diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7356e9e..bd96cf7 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -26,9 +26,9 @@ jobs:
       github.repository == 'stainless-sdks/stagehand-ruby' &&
       (github.event_name == 'push' || github.event.pull_request.head.repo.fork) && (github.event_name != 'push' || github.event.head_commit.message != 'codegen metadata')
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
       - name: Set up Ruby
-        uses: ruby/setup-ruby@v1
+        uses: ruby/setup-ruby@c4e5b1316158f92e3d49443a9d58b31d25ac0f8f # v1.306.0
         with:
           bundler-cache: false
       - run: |-
@@ -39,7 +39,7 @@ jobs:
           github.repository == 'stainless-sdks/stagehand-ruby' &&
           !startsWith(github.ref, 'refs/heads/stl/')
         id: github-oidc
-        uses: actions/github-script@v8
+        uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8.0.0
         with:
           script: core.setOutput('github_token', await core.getIDToken());
 
@@ -60,9 +60,9 @@ jobs:
     if: github.event_name == 'push' || github.event.pull_request.head.repo.fork
 
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
       - name: Set up Ruby
-        uses: ruby/setup-ruby@v1
+        uses: ruby/setup-ruby@c4e5b1316158f92e3d49443a9d58b31d25ac0f8f # v1.306.0
         with:
           bundler-cache: false
       - run: |-
@@ -76,9 +76,9 @@ jobs:
     runs-on: ${{ github.repository == 'stainless-sdks/stagehand-ruby' && 'depot-ubuntu-24.04' || 'ubuntu-latest' }}
     if: github.event_name == 'push' || github.event.pull_request.head.repo.fork
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
       - name: Set up Ruby
-        uses: ruby/setup-ruby@v1
+        uses: ruby/setup-ruby@c4e5b1316158f92e3d49443a9d58b31d25ac0f8f # v1.306.0
         with:
           bundler-cache: false
       - run: |-
diff --git a/.github/workflows/publish-gem.yml b/.github/workflows/publish-gem.yml
index 160f82b..c47e5b8 100644
--- a/.github/workflows/publish-gem.yml
+++ b/.github/workflows/publish-gem.yml
@@ -14,9 +14,9 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
       - name: Set up Ruby
-        uses: ruby/setup-ruby@v1
+        uses: ruby/setup-ruby@c4e5b1316158f92e3d49443a9d58b31d25ac0f8f # v1.306.0
         with:
           bundler-cache: false
       - run: |-
diff --git a/.github/workflows/release-doctor.yml b/.github/workflows/release-doctor.yml
index 801df3e..e75d806 100644
--- a/.github/workflows/release-doctor.yml
+++ b/.github/workflows/release-doctor.yml
@@ -12,7 +12,7 @@ jobs:
     if: github.repository == 'browserbase/stagehand-ruby' && (github.event_name == 'push' || github.event_name == 'workflow_dispatch' || startsWith(github.head_ref, 'release-please') || github.head_ref == 'next')
 
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
       - name: Check release environment
         run: |
diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index d11c8fc..eba8a04 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "3.20.0"
+  ".": "3.21.0"
 }
\ No newline at end of file
diff --git a/.stats.yml b/.stats.yml
index 391cde3..15099ca 100644
--- a/.stats.yml
+++ b/.stats.yml
@@ -1,4 +1,4 @@
 configured_endpoints: 8
-openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/browserbase/stagehand-6f6bfb81d092f30a5e2005328c97d61b9ea36132bb19e9e79e55294b9534ce20.yml
-openapi_spec_hash: f3fc1e3688a38dc2c28f7178f7d534e5
+openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/browserbase/stagehand-c7910965e66e73ad8b65b6cc391d431094b2a6c6577c3e9d82feaa8138e74cff.yml
+openapi_spec_hash: 37748bb69c22a9ce721d9b5a5861f964
 config_hash: 1fb12ae9b478488bc1e56bfbdc210b01
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8fd0ed0..8cf228c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,21 @@
 # Changelog
 
+## 3.21.0 (2026-05-27)
+
+Full Changelog: [v3.20.0...v3.21.0](https://github.com/browserbase/stagehand-ruby/compare/v3.20.0...v3.21.0)
+
+### Features
+
+* [feat]: add `ignoreSelectors` to `observe()` ([0acc093](https://github.com/browserbase/stagehand-ruby/commit/0acc093944e72ee488393ec1fb73dc16450cc825))
+* [STG-1756] forward Vertex model config ([f9752bc](https://github.com/browserbase/stagehand-ruby/commit/f9752bc3297bb9feef4d4b46d7faeac2a5e73335))
+* Add `screenshot` option to Extract ([7b65ca7](https://github.com/browserbase/stagehand-ruby/commit/7b65ca776e1e13c489f13991b012fa24aecc60e6))
+* STG-1756 add Vertex auth params to Stagehand spec ([4b65f22](https://github.com/browserbase/stagehand-ruby/commit/4b65f221055c7d0d3d7426845fbd0e49ba13d2df))
+
+
+### Bug Fixes
+
+* **client:** elide content type header on requests without body ([6149c11](https://github.com/browserbase/stagehand-ruby/commit/6149c11d9ab60a0cac69f1e26e3a2f42425ad616))
+
 ## 3.20.0 (2026-05-06)
 
 Full Changelog: [v3.19.3...v3.20.0](https://github.com/browserbase/stagehand-ruby/compare/v3.19.3...v3.20.0)
diff --git a/Gemfile.lock b/Gemfile.lock
index 4490644..adcbab3 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -11,7 +11,7 @@ GIT
 PATH
   remote: .
   specs:
-    stagehand (3.20.0)
+    stagehand (3.21.0)
       cgi
       connection_pool
 
diff --git a/lib/stagehand/internal/transport/base_client.rb b/lib/stagehand/internal/transport/base_client.rb
index 54200c4..9b452d3 100644
--- a/lib/stagehand/internal/transport/base_client.rb
+++ b/lib/stagehand/internal/transport/base_client.rb
@@ -306,6 +306,8 @@ def initialize(
               Stagehand::Internal::Util.deep_merge(*[req[:body], opts[:extra_body]].compact)
             end
 
+          headers.delete("content-type") if body.nil?
+
           url = Stagehand::Internal::Util.join_parsed_uri(
             @base_url_components,
             {**req, path: path, query: query}
diff --git a/lib/stagehand/internal/type/union.rb b/lib/stagehand/internal/type/union.rb
index 14b9cfe..aac57d0 100644
--- a/lib/stagehand/internal/type/union.rb
+++ b/lib/stagehand/internal/type/union.rb
@@ -4,6 +4,17 @@ module Stagehand
   module Internal
     module Type
       # @api private
+      #
+      # @example
+      #   # `model_config` is a `Stagehand::ModelConfig`
+      #   case model_config
+      #   when Stagehand::ModelConfig::VertexModelConfigObject
+      #     puts(model_config.auth)
+      #   when Stagehand::ModelConfig::GenericModelConfigObject
+      #     puts(model_config.model_name)
+      #   else
+      #     puts(model_config)
+      #   end
       module Union
         include Stagehand::Internal::Type::Converter
         include Stagehand::Internal::Util::SorbetRuntimeSupport
diff --git a/lib/stagehand/models/model_config.rb b/lib/stagehand/models/model_config.rb
index 806ca18..92281b1 100644
--- a/lib/stagehand/models/model_config.rb
+++ b/lib/stagehand/models/model_config.rb
@@ -2,63 +2,333 @@
 
 module Stagehand
   module Models
-    class ModelConfig < Stagehand::Internal::Type::BaseModel
-      # @!attribute model_name
-      #   Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
-      #
-      #   @return [String]
-      required :model_name, String, api_name: :modelName
-
-      # @!attribute api_key
-      #   API key for the model provider
-      #
-      #   @return [String, nil]
-      optional :api_key, String, api_name: :apiKey
-
-      # @!attribute base_url
-      #   Base URL for the model provider
-      #
-      #   @return [String, nil]
-      optional :base_url, String, api_name: :baseURL
-
-      # @!attribute headers
-      #   Custom headers sent with every request to the model provider
-      #
-      #   @return [Hash{Symbol=>String}, nil]
-      optional :headers, Stagehand::Internal::Type::HashOf[String]
-
-      # @!attribute provider
-      #   AI provider for the model (or provide a baseURL endpoint instead)
-      #
-      #   @return [Symbol, Stagehand::Models::ModelConfig::Provider, nil]
-      optional :provider, enum: -> { Stagehand::ModelConfig::Provider }
-
-      # @!method initialize(model_name:, api_key: nil, base_url: nil, headers: nil, provider: nil)
-      #   @param model_name [String] Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
-      #
-      #   @param api_key [String] API key for the model provider
-      #
-      #   @param base_url [String] Base URL for the model provider
-      #
-      #   @param headers [Hash{Symbol=>String}] Custom headers sent with every request to the model provider
-      #
-      #   @param provider [Symbol, Stagehand::Models::ModelConfig::Provider] AI provider for the model (or provide a baseURL endpoint instead)
-
-      # AI provider for the model (or provide a baseURL endpoint instead)
-      #
-      # @see Stagehand::Models::ModelConfig#provider
-      module Provider
-        extend Stagehand::Internal::Type::Enum
-
-        OPENAI = :openai
-        ANTHROPIC = :anthropic
-        GOOGLE = :google
-        MICROSOFT = :microsoft
-        BEDROCK = :bedrock
-
-        # @!method self.values
-        #   @return [Array<Symbol>]
+    module ModelConfig
+      extend Stagehand::Internal::Type::Union
+
+      variant -> { Stagehand::ModelConfig::VertexModelConfigObject }
+
+      variant -> { Stagehand::ModelConfig::GenericModelConfigObject }
+
+      class VertexModelConfigObject < Stagehand::Internal::Type::BaseModel
+        # @!attribute auth
+        #   Vertex provider authentication configuration
+        #
+        #   @return [Stagehand::Models::ModelConfig::VertexModelConfigObject::Auth]
+        required :auth, -> { Stagehand::ModelConfig::VertexModelConfigObject::Auth }
+
+        # @!attribute model_name
+        #   Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+        #
+        #   @return [String]
+        required :model_name, String, api_name: :modelName
+
+        # @!attribute provider
+        #   Vertex AI model provider
+        #
+        #   @return [Symbol, :vertex]
+        required :provider, const: :vertex
+
+        # @!attribute provider_options
+        #   Vertex provider-specific model configuration
+        #
+        #   @return [Stagehand::Models::ModelConfig::VertexModelConfigObject::ProviderOptions]
+        required :provider_options,
+                 -> { Stagehand::ModelConfig::VertexModelConfigObject::ProviderOptions },
+                 api_name: :providerOptions
+
+        # @!attribute api_key
+        #   API key for the model provider
+        #
+        #   @return [String, nil]
+        optional :api_key, String, api_name: :apiKey
+
+        # @!attribute base_url
+        #   Base URL for the model provider
+        #
+        #   @return [String, nil]
+        optional :base_url, String, api_name: :baseURL
+
+        # @!attribute headers
+        #   Custom headers sent with every request to the model provider
+        #
+        #   @return [Hash{Symbol=>String}, nil]
+        optional :headers, Stagehand::Internal::Type::HashOf[String]
+
+        # @!method initialize(auth:, model_name:, provider_options:, api_key: nil, base_url: nil, headers: nil, provider: :vertex)
+        #   @param auth [Stagehand::Models::ModelConfig::VertexModelConfigObject::Auth] Vertex provider authentication configuration
+        #
+        #   @param model_name [String] Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+        #
+        #   @param provider_options [Stagehand::Models::ModelConfig::VertexModelConfigObject::ProviderOptions] Vertex provider-specific model configuration
+        #
+        #   @param api_key [String] API key for the model provider
+        #
+        #   @param base_url [String] Base URL for the model provider
+        #
+        #   @param headers [Hash{Symbol=>String}] Custom headers sent with every request to the model provider
+        #
+        #   @param provider [Symbol, :vertex] Vertex AI model provider
+
+        # @see Stagehand::Models::ModelConfig::VertexModelConfigObject#auth
+        class Auth < Stagehand::Internal::Type::BaseModel
+          # @!attribute credentials
+          #   Google Cloud service account credentials
+          #
+          #   @return [Stagehand::Models::ModelConfig::VertexModelConfigObject::Auth::Credentials]
+          required :credentials, -> { Stagehand::ModelConfig::VertexModelConfigObject::Auth::Credentials }
+
+          # @!attribute type
+          #   Use inline Google Cloud service account credentials for provider authentication
+          #
+          #   @return [Symbol, :googleServiceAccount]
+          required :type, const: :googleServiceAccount
+
+          # @!attribute project_id
+          #   Google Cloud project ID used by google-auth-library
+          #
+          #   @return [String, nil]
+          optional :project_id, String, api_name: :projectId
+
+          # @!attribute scopes
+          #   Google auth scopes for the desired API request
+          #
+          #   @return [String, Array<String>, nil]
+          optional :scopes, union: -> { Stagehand::ModelConfig::VertexModelConfigObject::Auth::Scopes }
+
+          # @!attribute universe_domain
+          #   Google Cloud universe domain
+          #
+          #   @return [String, nil]
+          optional :universe_domain, String, api_name: :universeDomain
+
+          # @!method initialize(credentials:, project_id: nil, scopes: nil, universe_domain: nil, type: :googleServiceAccount)
+          #   Vertex provider authentication configuration
+          #
+          #   @param credentials [Stagehand::Models::ModelConfig::VertexModelConfigObject::Auth::Credentials] Google Cloud service account credentials
+          #
+          #   @param project_id [String] Google Cloud project ID used by google-auth-library
+          #
+          #   @param scopes [String, Array<String>] Google auth scopes for the desired API request
+          #
+          #   @param universe_domain [String] Google Cloud universe domain
+          #
+          #   @param type [Symbol, :googleServiceAccount] Use inline Google Cloud service account credentials for provider authentication
+
+          # @see Stagehand::Models::ModelConfig::VertexModelConfigObject::Auth#credentials
+          class Credentials < Stagehand::Internal::Type::BaseModel
+            # @!attribute client_email
+            #
+            #   @return [String]
+            required :client_email, String
+
+            # @!attribute private_key
+            #
+            #   @return [String]
+            required :private_key, String
+
+            # @!attribute auth_provider_x509_cert_url
+            #
+            #   @return [String, nil]
+            optional :auth_provider_x509_cert_url, String
+
+            # @!attribute auth_uri
+            #
+            #   @return [String, nil]
+            optional :auth_uri, String
+
+            # @!attribute client_id
+            #
+            #   @return [String, nil]
+            optional :client_id, String
+
+            # @!attribute client_x509_cert_url
+            #
+            #   @return [String, nil]
+            optional :client_x509_cert_url, String
+
+            # @!attribute private_key_id
+            #
+            #   @return [String, nil]
+            optional :private_key_id, String
+
+            # @!attribute project_id
+            #
+            #   @return [String, nil]
+            optional :project_id, String
+
+            # @!attribute token_uri
+            #
+            #   @return [String, nil]
+            optional :token_uri, String
+
+            # @!attribute type
+            #
+            #   @return [Symbol, Stagehand::Models::ModelConfig::VertexModelConfigObject::Auth::Credentials::Type, nil]
+            optional :type, enum: -> { Stagehand::ModelConfig::VertexModelConfigObject::Auth::Credentials::Type }
+
+            # @!attribute universe_domain
+            #
+            #   @return [String, nil]
+            optional :universe_domain, String
+
+            # @!method initialize(client_email:, private_key:, auth_provider_x509_cert_url: nil, auth_uri: nil, client_id: nil, client_x509_cert_url: nil, private_key_id: nil, project_id: nil, token_uri: nil, type: nil, universe_domain: nil)
+            #   Google Cloud service account credentials
+            #
+            #   @param client_email [String]
+            #   @param private_key [String]
+            #   @param auth_provider_x509_cert_url [String]
+            #   @param auth_uri [String]
+            #   @param client_id [String]
+            #   @param client_x509_cert_url [String]
+            #   @param private_key_id [String]
+            #   @param project_id [String]
+            #   @param token_uri [String]
+            #   @param type [Symbol, Stagehand::Models::ModelConfig::VertexModelConfigObject::Auth::Credentials::Type]
+            #   @param universe_domain [String]
+
+            # @see Stagehand::Models::ModelConfig::VertexModelConfigObject::Auth::Credentials#type
+            module Type
+              extend Stagehand::Internal::Type::Enum
+
+              SERVICE_ACCOUNT = :service_account
+
+              # @!method self.values
+              #   @return [Array<Symbol>]
+            end
+          end
+
+          # Google auth scopes for the desired API request
+          #
+          # @see Stagehand::Models::ModelConfig::VertexModelConfigObject::Auth#scopes
+          module Scopes
+            extend Stagehand::Internal::Type::Union
+
+            variant String
+
+            variant -> { Stagehand::Models::ModelConfig::VertexModelConfigObject::Auth::Scopes::StringArray }
+
+            # @!method self.variants
+            #   @return [Array(String, Array<String>)]
+
+            # @type [Stagehand::Internal::Type::Converter]
+            StringArray = Stagehand::Internal::Type::ArrayOf[String]
+          end
+        end
+
+        # @see Stagehand::Models::ModelConfig::VertexModelConfigObject#provider_options
+        class ProviderOptions < Stagehand::Internal::Type::BaseModel
+          # @!attribute vertex
+          #   Vertex AI provider-specific settings
+          #
+          #   @return [Stagehand::Models::ModelConfig::VertexModelConfigObject::ProviderOptions::Vertex]
+          required :vertex, -> { Stagehand::ModelConfig::VertexModelConfigObject::ProviderOptions::Vertex }
+
+          # @!method initialize(vertex:)
+          #   Vertex provider-specific model configuration
+          #
+          #   @param vertex [Stagehand::Models::ModelConfig::VertexModelConfigObject::ProviderOptions::Vertex] Vertex AI provider-specific settings
+
+          # @see Stagehand::Models::ModelConfig::VertexModelConfigObject::ProviderOptions#vertex
+          class Vertex < Stagehand::Internal::Type::BaseModel
+            # @!attribute location
+            #   Google Cloud location for Vertex AI models
+            #
+            #   @return [String]
+            required :location, String
+
+            # @!attribute project
+            #   Google Cloud project ID for Vertex AI models
+            #
+            #   @return [String]
+            required :project, String
+
+            # @!attribute base_url
+            #   Base URL for the Vertex AI provider
+            #
+            #   @return [String, nil]
+            optional :base_url, String, api_name: :baseURL
+
+            # @!attribute headers
+            #   Custom headers sent with every request to the Vertex AI provider
+            #
+            #   @return [Hash{Symbol=>String}, nil]
+            optional :headers, Stagehand::Internal::Type::HashOf[String]
+
+            # @!method initialize(location:, project:, base_url: nil, headers: nil)
+            #   Vertex AI provider-specific settings
+            #
+            #   @param location [String] Google Cloud location for Vertex AI models
+            #
+            #   @param project [String] Google Cloud project ID for Vertex AI models
+            #
+            #   @param base_url [String] Base URL for the Vertex AI provider
+            #
+            #   @param headers [Hash{Symbol=>String}] Custom headers sent with every request to the Vertex AI provider
+          end
+        end
       end
+
+      class GenericModelConfigObject < Stagehand::Internal::Type::BaseModel
+        # @!attribute model_name
+        #   Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+        #
+        #   @return [String]
+        required :model_name, String, api_name: :modelName
+
+        # @!attribute api_key
+        #   API key for the model provider
+        #
+        #   @return [String, nil]
+        optional :api_key, String, api_name: :apiKey
+
+        # @!attribute base_url
+        #   Base URL for the model provider
+        #
+        #   @return [String, nil]
+        optional :base_url, String, api_name: :baseURL
+
+        # @!attribute headers
+        #   Custom headers sent with every request to the model provider
+        #
+        #   @return [Hash{Symbol=>String}, nil]
+        optional :headers, Stagehand::Internal::Type::HashOf[String]
+
+        # @!attribute provider
+        #   AI provider for the model (or provide a baseURL endpoint instead)
+        #
+        #   @return [Symbol, Stagehand::Models::ModelConfig::GenericModelConfigObject::Provider, nil]
+        optional :provider, enum: -> { Stagehand::ModelConfig::GenericModelConfigObject::Provider }
+
+        # @!method initialize(model_name:, api_key: nil, base_url: nil, headers: nil, provider: nil)
+        #   @param model_name [String] Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+        #
+        #   @param api_key [String] API key for the model provider
+        #
+        #   @param base_url [String] Base URL for the model provider
+        #
+        #   @param headers [Hash{Symbol=>String}] Custom headers sent with every request to the model provider
+        #
+        #   @param provider [Symbol, Stagehand::Models::ModelConfig::GenericModelConfigObject::Provider] AI provider for the model (or provide a baseURL endpoint instead)
+
+        # AI provider for the model (or provide a baseURL endpoint instead)
+        #
+        # @see Stagehand::Models::ModelConfig::GenericModelConfigObject#provider
+        module Provider
+          extend Stagehand::Internal::Type::Enum
+
+          OPENAI = :openai
+          ANTHROPIC = :anthropic
+          GOOGLE = :google
+          MICROSOFT = :microsoft
+          BEDROCK = :bedrock
+
+          # @!method self.values
+          #   @return [Array<Symbol>]
+        end
+      end
+
+      # @!method self.variants
+      #   @return [Array(Stagehand::Models::ModelConfig::VertexModelConfigObject, Stagehand::Models::ModelConfig::GenericModelConfigObject)]
     end
   end
 end
diff --git a/lib/stagehand/models/session_act_params.rb b/lib/stagehand/models/session_act_params.rb
index ae7488b..9ed0570 100644
--- a/lib/stagehand/models/session_act_params.rb
+++ b/lib/stagehand/models/session_act_params.rb
@@ -68,7 +68,7 @@ class Options < Stagehand::Internal::Type::BaseModel
         # @!attribute model
         #   Model configuration object or model name string (e.g., 'openai/gpt-5-nano')
         #
-        #   @return [Stagehand::Models::ModelConfig, String, nil]
+        #   @return [Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject, Stagehand::Models::SessionActParams::Options::Model::GenericModelConfigObject, String, nil]
         optional :model, union: -> { Stagehand::SessionActParams::Options::Model }
 
         # @!attribute timeout
@@ -89,7 +89,7 @@ class Options < Stagehand::Internal::Type::BaseModel
         #   Some parameter documentations has been truncated, see
         #   {Stagehand::Models::SessionActParams::Options} for more details.
         #
-        #   @param model [Stagehand::Models::ModelConfig, String] Model configuration object or model name string (e.g., 'openai/gpt-5-nano')
+        #   @param model [Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject, Stagehand::Models::SessionActParams::Options::Model::GenericModelConfigObject, String] Model configuration object or model name string (e.g., 'openai/gpt-5-nano')
         #
         #   @param timeout [Float] Timeout in ms for the action
         #
@@ -101,12 +101,339 @@ class Options < Stagehand::Internal::Type::BaseModel
         module Model
           extend Stagehand::Internal::Type::Union
 
-          variant -> { Stagehand::ModelConfig }
+          variant -> { Stagehand::SessionActParams::Options::Model::VertexModelConfigObject }
+
+          variant -> { Stagehand::SessionActParams::Options::Model::GenericModelConfigObject }
 
           variant String
 
+          class VertexModelConfigObject < Stagehand::Internal::Type::BaseModel
+            # @!attribute auth
+            #   Vertex provider authentication configuration
+            #
+            #   @return [Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::Auth]
+            required :auth, -> { Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth }
+
+            # @!attribute model_name
+            #   Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            #
+            #   @return [String]
+            required :model_name, String, api_name: :modelName
+
+            # @!attribute provider
+            #   Vertex AI model provider
+            #
+            #   @return [Symbol, :vertex]
+            required :provider, const: :vertex
+
+            # @!attribute provider_options
+            #   Vertex provider-specific model configuration
+            #
+            #   @return [Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::ProviderOptions]
+            required :provider_options,
+                     -> {
+                       Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::ProviderOptions
+                     },
+                     api_name: :providerOptions
+
+            # @!attribute api_key
+            #   API key for the model provider
+            #
+            #   @return [String, nil]
+            optional :api_key, String, api_name: :apiKey
+
+            # @!attribute base_url
+            #   Base URL for the model provider
+            #
+            #   @return [String, nil]
+            optional :base_url, String, api_name: :baseURL
+
+            # @!attribute headers
+            #   Custom headers sent with every request to the model provider
+            #
+            #   @return [Hash{Symbol=>String}, nil]
+            optional :headers, Stagehand::Internal::Type::HashOf[String]
+
+            # @!method initialize(auth:, model_name:, provider_options:, api_key: nil, base_url: nil, headers: nil, provider: :vertex)
+            #   @param auth [Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::Auth] Vertex provider authentication configuration
+            #
+            #   @param model_name [String] Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            #
+            #   @param provider_options [Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::ProviderOptions] Vertex provider-specific model configuration
+            #
+            #   @param api_key [String] API key for the model provider
+            #
+            #   @param base_url [String] Base URL for the model provider
+            #
+            #   @param headers [Hash{Symbol=>String}] Custom headers sent with every request to the model provider
+            #
+            #   @param provider [Symbol, :vertex] Vertex AI model provider
+
+            # @see Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject#auth
+            class Auth < Stagehand::Internal::Type::BaseModel
+              # @!attribute credentials
+              #   Google Cloud service account credentials
+              #
+              #   @return [Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials]
+              required :credentials,
+                       -> { Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials }
+
+              # @!attribute type
+              #   Use inline Google Cloud service account credentials for provider authentication
+              #
+              #   @return [Symbol, :googleServiceAccount]
+              required :type, const: :googleServiceAccount
+
+              # @!attribute project_id
+              #   Google Cloud project ID used by google-auth-library
+              #
+              #   @return [String, nil]
+              optional :project_id, String, api_name: :projectId
+
+              # @!attribute scopes
+              #   Google auth scopes for the desired API request
+              #
+              #   @return [String, Array<String>, nil]
+              optional :scopes,
+                       union: -> { Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Scopes }
+
+              # @!attribute universe_domain
+              #   Google Cloud universe domain
+              #
+              #   @return [String, nil]
+              optional :universe_domain, String, api_name: :universeDomain
+
+              # @!method initialize(credentials:, project_id: nil, scopes: nil, universe_domain: nil, type: :googleServiceAccount)
+              #   Vertex provider authentication configuration
+              #
+              #   @param credentials [Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials] Google Cloud service account credentials
+              #
+              #   @param project_id [String] Google Cloud project ID used by google-auth-library
+              #
+              #   @param scopes [String, Array<String>] Google auth scopes for the desired API request
+              #
+              #   @param universe_domain [String] Google Cloud universe domain
+              #
+              #   @param type [Symbol, :googleServiceAccount] Use inline Google Cloud service account credentials for provider authentication
+
+              # @see Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::Auth#credentials
+              class Credentials < Stagehand::Internal::Type::BaseModel
+                # @!attribute client_email
+                #
+                #   @return [String]
+                required :client_email, String
+
+                # @!attribute private_key
+                #
+                #   @return [String]
+                required :private_key, String
+
+                # @!attribute auth_provider_x509_cert_url
+                #
+                #   @return [String, nil]
+                optional :auth_provider_x509_cert_url, String
+
+                # @!attribute auth_uri
+                #
+                #   @return [String, nil]
+                optional :auth_uri, String
+
+                # @!attribute client_id
+                #
+                #   @return [String, nil]
+                optional :client_id, String
+
+                # @!attribute client_x509_cert_url
+                #
+                #   @return [String, nil]
+                optional :client_x509_cert_url, String
+
+                # @!attribute private_key_id
+                #
+                #   @return [String, nil]
+                optional :private_key_id, String
+
+                # @!attribute project_id
+                #
+                #   @return [String, nil]
+                optional :project_id, String
+
+                # @!attribute token_uri
+                #
+                #   @return [String, nil]
+                optional :token_uri, String
+
+                # @!attribute type
+                #
+                #   @return [Symbol, Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type, nil]
+                optional :type,
+                         enum: -> { Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type }
+
+                # @!attribute universe_domain
+                #
+                #   @return [String, nil]
+                optional :universe_domain, String
+
+                # @!method initialize(client_email:, private_key:, auth_provider_x509_cert_url: nil, auth_uri: nil, client_id: nil, client_x509_cert_url: nil, private_key_id: nil, project_id: nil, token_uri: nil, type: nil, universe_domain: nil)
+                #   Google Cloud service account credentials
+                #
+                #   @param client_email [String]
+                #   @param private_key [String]
+                #   @param auth_provider_x509_cert_url [String]
+                #   @param auth_uri [String]
+                #   @param client_id [String]
+                #   @param client_x509_cert_url [String]
+                #   @param private_key_id [String]
+                #   @param project_id [String]
+                #   @param token_uri [String]
+                #   @param type [Symbol, Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type]
+                #   @param universe_domain [String]
+
+                # @see Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials#type
+                module Type
+                  extend Stagehand::Internal::Type::Enum
+
+                  SERVICE_ACCOUNT = :service_account
+
+                  # @!method self.values
+                  #   @return [Array<Symbol>]
+                end
+              end
+
+              # Google auth scopes for the desired API request
+              #
+              # @see Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::Auth#scopes
+              module Scopes
+                extend Stagehand::Internal::Type::Union
+
+                variant String
+
+                variant -> { Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Scopes::StringArray }
+
+                # @!method self.variants
+                #   @return [Array(String, Array<String>)]
+
+                # @type [Stagehand::Internal::Type::Converter]
+                StringArray = Stagehand::Internal::Type::ArrayOf[String]
+              end
+            end
+
+            # @see Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject#provider_options
+            class ProviderOptions < Stagehand::Internal::Type::BaseModel
+              # @!attribute vertex
+              #   Vertex AI provider-specific settings
+              #
+              #   @return [Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex]
+              required :vertex,
+                       -> { Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex }
+
+              # @!method initialize(vertex:)
+              #   Vertex provider-specific model configuration
+              #
+              #   @param vertex [Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex] Vertex AI provider-specific settings
+
+              # @see Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::ProviderOptions#vertex
+              class Vertex < Stagehand::Internal::Type::BaseModel
+                # @!attribute location
+                #   Google Cloud location for Vertex AI models
+                #
+                #   @return [String]
+                required :location, String
+
+                # @!attribute project
+                #   Google Cloud project ID for Vertex AI models
+                #
+                #   @return [String]
+                required :project, String
+
+                # @!attribute base_url
+                #   Base URL for the Vertex AI provider
+                #
+                #   @return [String, nil]
+                optional :base_url, String, api_name: :baseURL
+
+                # @!attribute headers
+                #   Custom headers sent with every request to the Vertex AI provider
+                #
+                #   @return [Hash{Symbol=>String}, nil]
+                optional :headers, Stagehand::Internal::Type::HashOf[String]
+
+                # @!method initialize(location:, project:, base_url: nil, headers: nil)
+                #   Vertex AI provider-specific settings
+                #
+                #   @param location [String] Google Cloud location for Vertex AI models
+                #
+                #   @param project [String] Google Cloud project ID for Vertex AI models
+                #
+                #   @param base_url [String] Base URL for the Vertex AI provider
+                #
+                #   @param headers [Hash{Symbol=>String}] Custom headers sent with every request to the Vertex AI provider
+              end
+            end
+          end
+
+          class GenericModelConfigObject < Stagehand::Internal::Type::BaseModel
+            # @!attribute model_name
+            #   Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            #
+            #   @return [String]
+            required :model_name, String, api_name: :modelName
+
+            # @!attribute api_key
+            #   API key for the model provider
+            #
+            #   @return [String, nil]
+            optional :api_key, String, api_name: :apiKey
+
+            # @!attribute base_url
+            #   Base URL for the model provider
+            #
+            #   @return [String, nil]
+            optional :base_url, String, api_name: :baseURL
+
+            # @!attribute headers
+            #   Custom headers sent with every request to the model provider
+            #
+            #   @return [Hash{Symbol=>String}, nil]
+            optional :headers, Stagehand::Internal::Type::HashOf[String]
+
+            # @!attribute provider
+            #   AI provider for the model (or provide a baseURL endpoint instead)
+            #
+            #   @return [Symbol, Stagehand::Models::SessionActParams::Options::Model::GenericModelConfigObject::Provider, nil]
+            optional :provider,
+                     enum: -> { Stagehand::SessionActParams::Options::Model::GenericModelConfigObject::Provider }
+
+            # @!method initialize(model_name:, api_key: nil, base_url: nil, headers: nil, provider: nil)
+            #   @param model_name [String] Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            #
+            #   @param api_key [String] API key for the model provider
+            #
+            #   @param base_url [String] Base URL for the model provider
+            #
+            #   @param headers [Hash{Symbol=>String}] Custom headers sent with every request to the model provider
+            #
+            #   @param provider [Symbol, Stagehand::Models::SessionActParams::Options::Model::GenericModelConfigObject::Provider] AI provider for the model (or provide a baseURL endpoint instead)
+
+            # AI provider for the model (or provide a baseURL endpoint instead)
+            #
+            # @see Stagehand::Models::SessionActParams::Options::Model::GenericModelConfigObject#provider
+            module Provider
+              extend Stagehand::Internal::Type::Enum
+
+              OPENAI = :openai
+              ANTHROPIC = :anthropic
+              GOOGLE = :google
+              MICROSOFT = :microsoft
+              BEDROCK = :bedrock
+
+              # @!method self.values
+              #   @return [Array<Symbol>]
+            end
+          end
+
           # @!method self.variants
-          #   @return [Array(Stagehand::Models::ModelConfig, String)]
+          #   @return [Array(Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject, Stagehand::Models::SessionActParams::Options::Model::GenericModelConfigObject, String)]
         end
 
         module Variable
diff --git a/lib/stagehand/models/session_execute_params.rb b/lib/stagehand/models/session_execute_params.rb
index 549fbc5..d71e506 100644
--- a/lib/stagehand/models/session_execute_params.rb
+++ b/lib/stagehand/models/session_execute_params.rb
@@ -73,7 +73,7 @@ class AgentConfig < Stagehand::Internal::Type::BaseModel
         #   tool execution (observe/act calls within agent tools). If not specified,
         #   inherits from the main model configuration.
         #
-        #   @return [Stagehand::Models::ModelConfig, String, nil]
+        #   @return [Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject, Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject, String, nil]
         optional :execution_model,
                  union: -> { Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel },
                  api_name: :executionModel
@@ -87,7 +87,7 @@ class AgentConfig < Stagehand::Internal::Type::BaseModel
         # @!attribute model
         #   Model configuration object or model name string (e.g., 'openai/gpt-5-nano')
         #
-        #   @return [Stagehand::Models::ModelConfig, String, nil]
+        #   @return [Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject, Stagehand::Models::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject, String, nil]
         optional :model, union: -> { Stagehand::SessionExecuteParams::AgentConfig::Model }
 
         # @!attribute provider
@@ -108,11 +108,11 @@ class AgentConfig < Stagehand::Internal::Type::BaseModel
         #
         #   @param cua [Boolean] Deprecated. Use mode: 'cua' instead. If both are provided, mode takes precedence
         #
-        #   @param execution_model [Stagehand::Models::ModelConfig, String] Model configuration object or model name string (e.g., 'openai/gpt-5-nano') for
+        #   @param execution_model [Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject, Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject, String] Model configuration object or model name string (e.g., 'openai/gpt-5-nano') for
         #
         #   @param mode [Symbol, Stagehand::Models::SessionExecuteParams::AgentConfig::Mode] Tool mode for the agent (dom, hybrid, cua). If set, overrides cua.
         #
-        #   @param model [Stagehand::Models::ModelConfig, String] Model configuration object or model name string (e.g., 'openai/gpt-5-nano')
+        #   @param model [Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject, Stagehand::Models::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject, String] Model configuration object or model name string (e.g., 'openai/gpt-5-nano')
         #
         #   @param provider [Symbol, Stagehand::Models::SessionExecuteParams::AgentConfig::Provider] AI provider for the agent (legacy, use model: openai/gpt-5-nano instead)
         #
@@ -126,12 +126,340 @@ class AgentConfig < Stagehand::Internal::Type::BaseModel
         module ExecutionModel
           extend Stagehand::Internal::Type::Union
 
-          variant -> { Stagehand::ModelConfig }
+          variant -> { Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject }
+
+          variant -> { Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject }
 
           variant String
 
+          class VertexModelConfigObject < Stagehand::Internal::Type::BaseModel
+            # @!attribute auth
+            #   Vertex provider authentication configuration
+            #
+            #   @return [Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth]
+            required :auth,
+                     -> { Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth }
+
+            # @!attribute model_name
+            #   Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            #
+            #   @return [String]
+            required :model_name, String, api_name: :modelName
+
+            # @!attribute provider
+            #   Vertex AI model provider
+            #
+            #   @return [Symbol, :vertex]
+            required :provider, const: :vertex
+
+            # @!attribute provider_options
+            #   Vertex provider-specific model configuration
+            #
+            #   @return [Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::ProviderOptions]
+            required :provider_options,
+                     -> {
+                       Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::ProviderOptions
+                     },
+                     api_name: :providerOptions
+
+            # @!attribute api_key
+            #   API key for the model provider
+            #
+            #   @return [String, nil]
+            optional :api_key, String, api_name: :apiKey
+
+            # @!attribute base_url
+            #   Base URL for the model provider
+            #
+            #   @return [String, nil]
+            optional :base_url, String, api_name: :baseURL
+
+            # @!attribute headers
+            #   Custom headers sent with every request to the model provider
+            #
+            #   @return [Hash{Symbol=>String}, nil]
+            optional :headers, Stagehand::Internal::Type::HashOf[String]
+
+            # @!method initialize(auth:, model_name:, provider_options:, api_key: nil, base_url: nil, headers: nil, provider: :vertex)
+            #   @param auth [Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth] Vertex provider authentication configuration
+            #
+            #   @param model_name [String] Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            #
+            #   @param provider_options [Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::ProviderOptions] Vertex provider-specific model configuration
+            #
+            #   @param api_key [String] API key for the model provider
+            #
+            #   @param base_url [String] Base URL for the model provider
+            #
+            #   @param headers [Hash{Symbol=>String}] Custom headers sent with every request to the model provider
+            #
+            #   @param provider [Symbol, :vertex] Vertex AI model provider
+
+            # @see Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject#auth
+            class Auth < Stagehand::Internal::Type::BaseModel
+              # @!attribute credentials
+              #   Google Cloud service account credentials
+              #
+              #   @return [Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials]
+              required :credentials,
+                       -> { Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials }
+
+              # @!attribute type
+              #   Use inline Google Cloud service account credentials for provider authentication
+              #
+              #   @return [Symbol, :googleServiceAccount]
+              required :type, const: :googleServiceAccount
+
+              # @!attribute project_id
+              #   Google Cloud project ID used by google-auth-library
+              #
+              #   @return [String, nil]
+              optional :project_id, String, api_name: :projectId
+
+              # @!attribute scopes
+              #   Google auth scopes for the desired API request
+              #
+              #   @return [String, Array<String>, nil]
+              optional :scopes,
+                       union: -> { Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Scopes }
+
+              # @!attribute universe_domain
+              #   Google Cloud universe domain
+              #
+              #   @return [String, nil]
+              optional :universe_domain, String, api_name: :universeDomain
+
+              # @!method initialize(credentials:, project_id: nil, scopes: nil, universe_domain: nil, type: :googleServiceAccount)
+              #   Vertex provider authentication configuration
+              #
+              #   @param credentials [Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials] Google Cloud service account credentials
+              #
+              #   @param project_id [String] Google Cloud project ID used by google-auth-library
+              #
+              #   @param scopes [String, Array<String>] Google auth scopes for the desired API request
+              #
+              #   @param universe_domain [String] Google Cloud universe domain
+              #
+              #   @param type [Symbol, :googleServiceAccount] Use inline Google Cloud service account credentials for provider authentication
+
+              # @see Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth#credentials
+              class Credentials < Stagehand::Internal::Type::BaseModel
+                # @!attribute client_email
+                #
+                #   @return [String]
+                required :client_email, String
+
+                # @!attribute private_key
+                #
+                #   @return [String]
+                required :private_key, String
+
+                # @!attribute auth_provider_x509_cert_url
+                #
+                #   @return [String, nil]
+                optional :auth_provider_x509_cert_url, String
+
+                # @!attribute auth_uri
+                #
+                #   @return [String, nil]
+                optional :auth_uri, String
+
+                # @!attribute client_id
+                #
+                #   @return [String, nil]
+                optional :client_id, String
+
+                # @!attribute client_x509_cert_url
+                #
+                #   @return [String, nil]
+                optional :client_x509_cert_url, String
+
+                # @!attribute private_key_id
+                #
+                #   @return [String, nil]
+                optional :private_key_id, String
+
+                # @!attribute project_id
+                #
+                #   @return [String, nil]
+                optional :project_id, String
+
+                # @!attribute token_uri
+                #
+                #   @return [String, nil]
+                optional :token_uri, String
+
+                # @!attribute type
+                #
+                #   @return [Symbol, Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials::Type, nil]
+                optional :type,
+                         enum: -> { Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials::Type }
+
+                # @!attribute universe_domain
+                #
+                #   @return [String, nil]
+                optional :universe_domain, String
+
+                # @!method initialize(client_email:, private_key:, auth_provider_x509_cert_url: nil, auth_uri: nil, client_id: nil, client_x509_cert_url: nil, private_key_id: nil, project_id: nil, token_uri: nil, type: nil, universe_domain: nil)
+                #   Google Cloud service account credentials
+                #
+                #   @param client_email [String]
+                #   @param private_key [String]
+                #   @param auth_provider_x509_cert_url [String]
+                #   @param auth_uri [String]
+                #   @param client_id [String]
+                #   @param client_x509_cert_url [String]
+                #   @param private_key_id [String]
+                #   @param project_id [String]
+                #   @param token_uri [String]
+                #   @param type [Symbol, Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials::Type]
+                #   @param universe_domain [String]
+
+                # @see Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials#type
+                module Type
+                  extend Stagehand::Internal::Type::Enum
+
+                  SERVICE_ACCOUNT = :service_account
+
+                  # @!method self.values
+                  #   @return [Array<Symbol>]
+                end
+              end
+
+              # Google auth scopes for the desired API request
+              #
+              # @see Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth#scopes
+              module Scopes
+                extend Stagehand::Internal::Type::Union
+
+                variant String
+
+                variant -> { Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Scopes::StringArray }
+
+                # @!method self.variants
+                #   @return [Array(String, Array<String>)]
+
+                # @type [Stagehand::Internal::Type::Converter]
+                StringArray = Stagehand::Internal::Type::ArrayOf[String]
+              end
+            end
+
+            # @see Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject#provider_options
+            class ProviderOptions < Stagehand::Internal::Type::BaseModel
+              # @!attribute vertex
+              #   Vertex AI provider-specific settings
+              #
+              #   @return [Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::ProviderOptions::Vertex]
+              required :vertex,
+                       -> { Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::ProviderOptions::Vertex }
+
+              # @!method initialize(vertex:)
+              #   Vertex provider-specific model configuration
+              #
+              #   @param vertex [Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::ProviderOptions::Vertex] Vertex AI provider-specific settings
+
+              # @see Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::ProviderOptions#vertex
+              class Vertex < Stagehand::Internal::Type::BaseModel
+                # @!attribute location
+                #   Google Cloud location for Vertex AI models
+                #
+                #   @return [String]
+                required :location, String
+
+                # @!attribute project
+                #   Google Cloud project ID for Vertex AI models
+                #
+                #   @return [String]
+                required :project, String
+
+                # @!attribute base_url
+                #   Base URL for the Vertex AI provider
+                #
+                #   @return [String, nil]
+                optional :base_url, String, api_name: :baseURL
+
+                # @!attribute headers
+                #   Custom headers sent with every request to the Vertex AI provider
+                #
+                #   @return [Hash{Symbol=>String}, nil]
+                optional :headers, Stagehand::Internal::Type::HashOf[String]
+
+                # @!method initialize(location:, project:, base_url: nil, headers: nil)
+                #   Vertex AI provider-specific settings
+                #
+                #   @param location [String] Google Cloud location for Vertex AI models
+                #
+                #   @param project [String] Google Cloud project ID for Vertex AI models
+                #
+                #   @param base_url [String] Base URL for the Vertex AI provider
+                #
+                #   @param headers [Hash{Symbol=>String}] Custom headers sent with every request to the Vertex AI provider
+              end
+            end
+          end
+
+          class GenericModelConfigObject < Stagehand::Internal::Type::BaseModel
+            # @!attribute model_name
+            #   Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            #
+            #   @return [String]
+            required :model_name, String, api_name: :modelName
+
+            # @!attribute api_key
+            #   API key for the model provider
+            #
+            #   @return [String, nil]
+            optional :api_key, String, api_name: :apiKey
+
+            # @!attribute base_url
+            #   Base URL for the model provider
+            #
+            #   @return [String, nil]
+            optional :base_url, String, api_name: :baseURL
+
+            # @!attribute headers
+            #   Custom headers sent with every request to the model provider
+            #
+            #   @return [Hash{Symbol=>String}, nil]
+            optional :headers, Stagehand::Internal::Type::HashOf[String]
+
+            # @!attribute provider
+            #   AI provider for the model (or provide a baseURL endpoint instead)
+            #
+            #   @return [Symbol, Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject::Provider, nil]
+            optional :provider,
+                     enum: -> { Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject::Provider }
+
+            # @!method initialize(model_name:, api_key: nil, base_url: nil, headers: nil, provider: nil)
+            #   @param model_name [String] Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            #
+            #   @param api_key [String] API key for the model provider
+            #
+            #   @param base_url [String] Base URL for the model provider
+            #
+            #   @param headers [Hash{Symbol=>String}] Custom headers sent with every request to the model provider
+            #
+            #   @param provider [Symbol, Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject::Provider] AI provider for the model (or provide a baseURL endpoint instead)
+
+            # AI provider for the model (or provide a baseURL endpoint instead)
+            #
+            # @see Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject#provider
+            module Provider
+              extend Stagehand::Internal::Type::Enum
+
+              OPENAI = :openai
+              ANTHROPIC = :anthropic
+              GOOGLE = :google
+              MICROSOFT = :microsoft
+              BEDROCK = :bedrock
+
+              # @!method self.values
+              #   @return [Array<Symbol>]
+            end
+          end
+
           # @!method self.variants
-          #   @return [Array(Stagehand::Models::ModelConfig, String)]
+          #   @return [Array(Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject, Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject, String)]
         end
 
         # Tool mode for the agent (dom, hybrid, cua). If set, overrides cua.
@@ -154,12 +482,339 @@ module Mode
         module Model
           extend Stagehand::Internal::Type::Union
 
-          variant -> { Stagehand::ModelConfig }
+          variant -> { Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject }
+
+          variant -> { Stagehand::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject }
 
           variant String
 
+          class VertexModelConfigObject < Stagehand::Internal::Type::BaseModel
+            # @!attribute auth
+            #   Vertex provider authentication configuration
+            #
+            #   @return [Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth]
+            required :auth, -> { Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth }
+
+            # @!attribute model_name
+            #   Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            #
+            #   @return [String]
+            required :model_name, String, api_name: :modelName
+
+            # @!attribute provider
+            #   Vertex AI model provider
+            #
+            #   @return [Symbol, :vertex]
+            required :provider, const: :vertex
+
+            # @!attribute provider_options
+            #   Vertex provider-specific model configuration
+            #
+            #   @return [Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::ProviderOptions]
+            required :provider_options,
+                     -> {
+                       Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::ProviderOptions
+                     },
+                     api_name: :providerOptions
+
+            # @!attribute api_key
+            #   API key for the model provider
+            #
+            #   @return [String, nil]
+            optional :api_key, String, api_name: :apiKey
+
+            # @!attribute base_url
+            #   Base URL for the model provider
+            #
+            #   @return [String, nil]
+            optional :base_url, String, api_name: :baseURL
+
+            # @!attribute headers
+            #   Custom headers sent with every request to the model provider
+            #
+            #   @return [Hash{Symbol=>String}, nil]
+            optional :headers, Stagehand::Internal::Type::HashOf[String]
+
+            # @!method initialize(auth:, model_name:, provider_options:, api_key: nil, base_url: nil, headers: nil, provider: :vertex)
+            #   @param auth [Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth] Vertex provider authentication configuration
+            #
+            #   @param model_name [String] Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            #
+            #   @param provider_options [Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::ProviderOptions] Vertex provider-specific model configuration
+            #
+            #   @param api_key [String] API key for the model provider
+            #
+            #   @param base_url [String] Base URL for the model provider
+            #
+            #   @param headers [Hash{Symbol=>String}] Custom headers sent with every request to the model provider
+            #
+            #   @param provider [Symbol, :vertex] Vertex AI model provider
+
+            # @see Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject#auth
+            class Auth < Stagehand::Internal::Type::BaseModel
+              # @!attribute credentials
+              #   Google Cloud service account credentials
+              #
+              #   @return [Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials]
+              required :credentials,
+                       -> { Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials }
+
+              # @!attribute type
+              #   Use inline Google Cloud service account credentials for provider authentication
+              #
+              #   @return [Symbol, :googleServiceAccount]
+              required :type, const: :googleServiceAccount
+
+              # @!attribute project_id
+              #   Google Cloud project ID used by google-auth-library
+              #
+              #   @return [String, nil]
+              optional :project_id, String, api_name: :projectId
+
+              # @!attribute scopes
+              #   Google auth scopes for the desired API request
+              #
+              #   @return [String, Array<String>, nil]
+              optional :scopes,
+                       union: -> { Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Scopes }
+
+              # @!attribute universe_domain
+              #   Google Cloud universe domain
+              #
+              #   @return [String, nil]
+              optional :universe_domain, String, api_name: :universeDomain
+
+              # @!method initialize(credentials:, project_id: nil, scopes: nil, universe_domain: nil, type: :googleServiceAccount)
+              #   Vertex provider authentication configuration
+              #
+              #   @param credentials [Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials] Google Cloud service account credentials
+              #
+              #   @param project_id [String] Google Cloud project ID used by google-auth-library
+              #
+              #   @param scopes [String, Array<String>] Google auth scopes for the desired API request
+              #
+              #   @param universe_domain [String] Google Cloud universe domain
+              #
+              #   @param type [Symbol, :googleServiceAccount] Use inline Google Cloud service account credentials for provider authentication
+
+              # @see Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth#credentials
+              class Credentials < Stagehand::Internal::Type::BaseModel
+                # @!attribute client_email
+                #
+                #   @return [String]
+                required :client_email, String
+
+                # @!attribute private_key
+                #
+                #   @return [String]
+                required :private_key, String
+
+                # @!attribute auth_provider_x509_cert_url
+                #
+                #   @return [String, nil]
+                optional :auth_provider_x509_cert_url, String
+
+                # @!attribute auth_uri
+                #
+                #   @return [String, nil]
+                optional :auth_uri, String
+
+                # @!attribute client_id
+                #
+                #   @return [String, nil]
+                optional :client_id, String
+
+                # @!attribute client_x509_cert_url
+                #
+                #   @return [String, nil]
+                optional :client_x509_cert_url, String
+
+                # @!attribute private_key_id
+                #
+                #   @return [String, nil]
+                optional :private_key_id, String
+
+                # @!attribute project_id
+                #
+                #   @return [String, nil]
+                optional :project_id, String
+
+                # @!attribute token_uri
+                #
+                #   @return [String, nil]
+                optional :token_uri, String
+
+                # @!attribute type
+                #
+                #   @return [Symbol, Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials::Type, nil]
+                optional :type,
+                         enum: -> { Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials::Type }
+
+                # @!attribute universe_domain
+                #
+                #   @return [String, nil]
+                optional :universe_domain, String
+
+                # @!method initialize(client_email:, private_key:, auth_provider_x509_cert_url: nil, auth_uri: nil, client_id: nil, client_x509_cert_url: nil, private_key_id: nil, project_id: nil, token_uri: nil, type: nil, universe_domain: nil)
+                #   Google Cloud service account credentials
+                #
+                #   @param client_email [String]
+                #   @param private_key [String]
+                #   @param auth_provider_x509_cert_url [String]
+                #   @param auth_uri [String]
+                #   @param client_id [String]
+                #   @param client_x509_cert_url [String]
+                #   @param private_key_id [String]
+                #   @param project_id [String]
+                #   @param token_uri [String]
+                #   @param type [Symbol, Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials::Type]
+                #   @param universe_domain [String]
+
+                # @see Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials#type
+                module Type
+                  extend Stagehand::Internal::Type::Enum
+
+                  SERVICE_ACCOUNT = :service_account
+
+                  # @!method self.values
+                  #   @return [Array<Symbol>]
+                end
+              end
+
+              # Google auth scopes for the desired API request
+              #
+              # @see Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth#scopes
+              module Scopes
+                extend Stagehand::Internal::Type::Union
+
+                variant String
+
+                variant -> { Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Scopes::StringArray }
+
+                # @!method self.variants
+                #   @return [Array(String, Array<String>)]
+
+                # @type [Stagehand::Internal::Type::Converter]
+                StringArray = Stagehand::Internal::Type::ArrayOf[String]
+              end
+            end
+
+            # @see Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject#provider_options
+            class ProviderOptions < Stagehand::Internal::Type::BaseModel
+              # @!attribute vertex
+              #   Vertex AI provider-specific settings
+              #
+              #   @return [Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::ProviderOptions::Vertex]
+              required :vertex,
+                       -> { Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::ProviderOptions::Vertex }
+
+              # @!method initialize(vertex:)
+              #   Vertex provider-specific model configuration
+              #
+              #   @param vertex [Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::ProviderOptions::Vertex] Vertex AI provider-specific settings
+
+              # @see Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::ProviderOptions#vertex
+              class Vertex < Stagehand::Internal::Type::BaseModel
+                # @!attribute location
+                #   Google Cloud location for Vertex AI models
+                #
+                #   @return [String]
+                required :location, String
+
+                # @!attribute project
+                #   Google Cloud project ID for Vertex AI models
+                #
+                #   @return [String]
+                required :project, String
+
+                # @!attribute base_url
+                #   Base URL for the Vertex AI provider
+                #
+                #   @return [String, nil]
+                optional :base_url, String, api_name: :baseURL
+
+                # @!attribute headers
+                #   Custom headers sent with every request to the Vertex AI provider
+                #
+                #   @return [Hash{Symbol=>String}, nil]
+                optional :headers, Stagehand::Internal::Type::HashOf[String]
+
+                # @!method initialize(location:, project:, base_url: nil, headers: nil)
+                #   Vertex AI provider-specific settings
+                #
+                #   @param location [String] Google Cloud location for Vertex AI models
+                #
+                #   @param project [String] Google Cloud project ID for Vertex AI models
+                #
+                #   @param base_url [String] Base URL for the Vertex AI provider
+                #
+                #   @param headers [Hash{Symbol=>String}] Custom headers sent with every request to the Vertex AI provider
+              end
+            end
+          end
+
+          class GenericModelConfigObject < Stagehand::Internal::Type::BaseModel
+            # @!attribute model_name
+            #   Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            #
+            #   @return [String]
+            required :model_name, String, api_name: :modelName
+
+            # @!attribute api_key
+            #   API key for the model provider
+            #
+            #   @return [String, nil]
+            optional :api_key, String, api_name: :apiKey
+
+            # @!attribute base_url
+            #   Base URL for the model provider
+            #
+            #   @return [String, nil]
+            optional :base_url, String, api_name: :baseURL
+
+            # @!attribute headers
+            #   Custom headers sent with every request to the model provider
+            #
+            #   @return [Hash{Symbol=>String}, nil]
+            optional :headers, Stagehand::Internal::Type::HashOf[String]
+
+            # @!attribute provider
+            #   AI provider for the model (or provide a baseURL endpoint instead)
+            #
+            #   @return [Symbol, Stagehand::Models::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject::Provider, nil]
+            optional :provider,
+                     enum: -> { Stagehand::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject::Provider }
+
+            # @!method initialize(model_name:, api_key: nil, base_url: nil, headers: nil, provider: nil)
+            #   @param model_name [String] Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            #
+            #   @param api_key [String] API key for the model provider
+            #
+            #   @param base_url [String] Base URL for the model provider
+            #
+            #   @param headers [Hash{Symbol=>String}] Custom headers sent with every request to the model provider
+            #
+            #   @param provider [Symbol, Stagehand::Models::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject::Provider] AI provider for the model (or provide a baseURL endpoint instead)
+
+            # AI provider for the model (or provide a baseURL endpoint instead)
+            #
+            # @see Stagehand::Models::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject#provider
+            module Provider
+              extend Stagehand::Internal::Type::Enum
+
+              OPENAI = :openai
+              ANTHROPIC = :anthropic
+              GOOGLE = :google
+              MICROSOFT = :microsoft
+              BEDROCK = :bedrock
+
+              # @!method self.values
+              #   @return [Array<Symbol>]
+            end
+          end
+
           # @!method self.variants
-          #   @return [Array(Stagehand::Models::ModelConfig, String)]
+          #   @return [Array(Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject, Stagehand::Models::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject, String)]
         end
 
         # AI provider for the agent (legacy, use model: openai/gpt-5-nano instead)
diff --git a/lib/stagehand/models/session_extract_params.rb b/lib/stagehand/models/session_extract_params.rb
index 1b304fb..ae043c3 100644
--- a/lib/stagehand/models/session_extract_params.rb
+++ b/lib/stagehand/models/session_extract_params.rb
@@ -69,9 +69,16 @@ class Options < Stagehand::Internal::Type::BaseModel
         # @!attribute model
         #   Model configuration object or model name string (e.g., 'openai/gpt-5-nano')
         #
-        #   @return [Stagehand::Models::ModelConfig, String, nil]
+        #   @return [Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject, Stagehand::Models::SessionExtractParams::Options::Model::GenericModelConfigObject, String, nil]
         optional :model, union: -> { Stagehand::SessionExtractParams::Options::Model }
 
+        # @!attribute screenshot
+        #   When true, include a screenshot of the current viewport in the extraction LLM
+        #   call. Defaults to false.
+        #
+        #   @return [Boolean, nil]
+        optional :screenshot, Stagehand::Internal::Type::Boolean
+
         # @!attribute selector
         #   CSS selector to scope extraction to a specific element
         #
@@ -84,10 +91,15 @@ class Options < Stagehand::Internal::Type::BaseModel
         #   @return [Float, nil]
         optional :timeout, Float
 
-        # @!method initialize(ignore_selectors: nil, model: nil, selector: nil, timeout: nil)
+        # @!method initialize(ignore_selectors: nil, model: nil, screenshot: nil, selector: nil, timeout: nil)
+        #   Some parameter documentations has been truncated, see
+        #   {Stagehand::Models::SessionExtractParams::Options} for more details.
+        #
         #   @param ignore_selectors [Array<String>] Selectors for elements and subtrees that should be excluded from extraction
         #
-        #   @param model [Stagehand::Models::ModelConfig, String] Model configuration object or model name string (e.g., 'openai/gpt-5-nano')
+        #   @param model [Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject, Stagehand::Models::SessionExtractParams::Options::Model::GenericModelConfigObject, String] Model configuration object or model name string (e.g., 'openai/gpt-5-nano')
+        #
+        #   @param screenshot [Boolean] When true, include a screenshot of the current viewport in the extraction LLM ca
         #
         #   @param selector [String] CSS selector to scope extraction to a specific element
         #
@@ -99,12 +111,339 @@ class Options < Stagehand::Internal::Type::BaseModel
         module Model
           extend Stagehand::Internal::Type::Union
 
-          variant -> { Stagehand::ModelConfig }
+          variant -> { Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject }
+
+          variant -> { Stagehand::SessionExtractParams::Options::Model::GenericModelConfigObject }
 
           variant String
 
+          class VertexModelConfigObject < Stagehand::Internal::Type::BaseModel
+            # @!attribute auth
+            #   Vertex provider authentication configuration
+            #
+            #   @return [Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth]
+            required :auth, -> { Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth }
+
+            # @!attribute model_name
+            #   Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            #
+            #   @return [String]
+            required :model_name, String, api_name: :modelName
+
+            # @!attribute provider
+            #   Vertex AI model provider
+            #
+            #   @return [Symbol, :vertex]
+            required :provider, const: :vertex
+
+            # @!attribute provider_options
+            #   Vertex provider-specific model configuration
+            #
+            #   @return [Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::ProviderOptions]
+            required :provider_options,
+                     -> {
+                       Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::ProviderOptions
+                     },
+                     api_name: :providerOptions
+
+            # @!attribute api_key
+            #   API key for the model provider
+            #
+            #   @return [String, nil]
+            optional :api_key, String, api_name: :apiKey
+
+            # @!attribute base_url
+            #   Base URL for the model provider
+            #
+            #   @return [String, nil]
+            optional :base_url, String, api_name: :baseURL
+
+            # @!attribute headers
+            #   Custom headers sent with every request to the model provider
+            #
+            #   @return [Hash{Symbol=>String}, nil]
+            optional :headers, Stagehand::Internal::Type::HashOf[String]
+
+            # @!method initialize(auth:, model_name:, provider_options:, api_key: nil, base_url: nil, headers: nil, provider: :vertex)
+            #   @param auth [Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth] Vertex provider authentication configuration
+            #
+            #   @param model_name [String] Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            #
+            #   @param provider_options [Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::ProviderOptions] Vertex provider-specific model configuration
+            #
+            #   @param api_key [String] API key for the model provider
+            #
+            #   @param base_url [String] Base URL for the model provider
+            #
+            #   @param headers [Hash{Symbol=>String}] Custom headers sent with every request to the model provider
+            #
+            #   @param provider [Symbol, :vertex] Vertex AI model provider
+
+            # @see Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject#auth
+            class Auth < Stagehand::Internal::Type::BaseModel
+              # @!attribute credentials
+              #   Google Cloud service account credentials
+              #
+              #   @return [Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials]
+              required :credentials,
+                       -> { Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials }
+
+              # @!attribute type
+              #   Use inline Google Cloud service account credentials for provider authentication
+              #
+              #   @return [Symbol, :googleServiceAccount]
+              required :type, const: :googleServiceAccount
+
+              # @!attribute project_id
+              #   Google Cloud project ID used by google-auth-library
+              #
+              #   @return [String, nil]
+              optional :project_id, String, api_name: :projectId
+
+              # @!attribute scopes
+              #   Google auth scopes for the desired API request
+              #
+              #   @return [String, Array<String>, nil]
+              optional :scopes,
+                       union: -> { Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Scopes }
+
+              # @!attribute universe_domain
+              #   Google Cloud universe domain
+              #
+              #   @return [String, nil]
+              optional :universe_domain, String, api_name: :universeDomain
+
+              # @!method initialize(credentials:, project_id: nil, scopes: nil, universe_domain: nil, type: :googleServiceAccount)
+              #   Vertex provider authentication configuration
+              #
+              #   @param credentials [Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials] Google Cloud service account credentials
+              #
+              #   @param project_id [String] Google Cloud project ID used by google-auth-library
+              #
+              #   @param scopes [String, Array<String>] Google auth scopes for the desired API request
+              #
+              #   @param universe_domain [String] Google Cloud universe domain
+              #
+              #   @param type [Symbol, :googleServiceAccount] Use inline Google Cloud service account credentials for provider authentication
+
+              # @see Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth#credentials
+              class Credentials < Stagehand::Internal::Type::BaseModel
+                # @!attribute client_email
+                #
+                #   @return [String]
+                required :client_email, String
+
+                # @!attribute private_key
+                #
+                #   @return [String]
+                required :private_key, String
+
+                # @!attribute auth_provider_x509_cert_url
+                #
+                #   @return [String, nil]
+                optional :auth_provider_x509_cert_url, String
+
+                # @!attribute auth_uri
+                #
+                #   @return [String, nil]
+                optional :auth_uri, String
+
+                # @!attribute client_id
+                #
+                #   @return [String, nil]
+                optional :client_id, String
+
+                # @!attribute client_x509_cert_url
+                #
+                #   @return [String, nil]
+                optional :client_x509_cert_url, String
+
+                # @!attribute private_key_id
+                #
+                #   @return [String, nil]
+                optional :private_key_id, String
+
+                # @!attribute project_id
+                #
+                #   @return [String, nil]
+                optional :project_id, String
+
+                # @!attribute token_uri
+                #
+                #   @return [String, nil]
+                optional :token_uri, String
+
+                # @!attribute type
+                #
+                #   @return [Symbol, Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type, nil]
+                optional :type,
+                         enum: -> { Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type }
+
+                # @!attribute universe_domain
+                #
+                #   @return [String, nil]
+                optional :universe_domain, String
+
+                # @!method initialize(client_email:, private_key:, auth_provider_x509_cert_url: nil, auth_uri: nil, client_id: nil, client_x509_cert_url: nil, private_key_id: nil, project_id: nil, token_uri: nil, type: nil, universe_domain: nil)
+                #   Google Cloud service account credentials
+                #
+                #   @param client_email [String]
+                #   @param private_key [String]
+                #   @param auth_provider_x509_cert_url [String]
+                #   @param auth_uri [String]
+                #   @param client_id [String]
+                #   @param client_x509_cert_url [String]
+                #   @param private_key_id [String]
+                #   @param project_id [String]
+                #   @param token_uri [String]
+                #   @param type [Symbol, Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type]
+                #   @param universe_domain [String]
+
+                # @see Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials#type
+                module Type
+                  extend Stagehand::Internal::Type::Enum
+
+                  SERVICE_ACCOUNT = :service_account
+
+                  # @!method self.values
+                  #   @return [Array<Symbol>]
+                end
+              end
+
+              # Google auth scopes for the desired API request
+              #
+              # @see Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth#scopes
+              module Scopes
+                extend Stagehand::Internal::Type::Union
+
+                variant String
+
+                variant -> { Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Scopes::StringArray }
+
+                # @!method self.variants
+                #   @return [Array(String, Array<String>)]
+
+                # @type [Stagehand::Internal::Type::Converter]
+                StringArray = Stagehand::Internal::Type::ArrayOf[String]
+              end
+            end
+
+            # @see Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject#provider_options
+            class ProviderOptions < Stagehand::Internal::Type::BaseModel
+              # @!attribute vertex
+              #   Vertex AI provider-specific settings
+              #
+              #   @return [Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex]
+              required :vertex,
+                       -> { Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex }
+
+              # @!method initialize(vertex:)
+              #   Vertex provider-specific model configuration
+              #
+              #   @param vertex [Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex] Vertex AI provider-specific settings
+
+              # @see Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::ProviderOptions#vertex
+              class Vertex < Stagehand::Internal::Type::BaseModel
+                # @!attribute location
+                #   Google Cloud location for Vertex AI models
+                #
+                #   @return [String]
+                required :location, String
+
+                # @!attribute project
+                #   Google Cloud project ID for Vertex AI models
+                #
+                #   @return [String]
+                required :project, String
+
+                # @!attribute base_url
+                #   Base URL for the Vertex AI provider
+                #
+                #   @return [String, nil]
+                optional :base_url, String, api_name: :baseURL
+
+                # @!attribute headers
+                #   Custom headers sent with every request to the Vertex AI provider
+                #
+                #   @return [Hash{Symbol=>String}, nil]
+                optional :headers, Stagehand::Internal::Type::HashOf[String]
+
+                # @!method initialize(location:, project:, base_url: nil, headers: nil)
+                #   Vertex AI provider-specific settings
+                #
+                #   @param location [String] Google Cloud location for Vertex AI models
+                #
+                #   @param project [String] Google Cloud project ID for Vertex AI models
+                #
+                #   @param base_url [String] Base URL for the Vertex AI provider
+                #
+                #   @param headers [Hash{Symbol=>String}] Custom headers sent with every request to the Vertex AI provider
+              end
+            end
+          end
+
+          class GenericModelConfigObject < Stagehand::Internal::Type::BaseModel
+            # @!attribute model_name
+            #   Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            #
+            #   @return [String]
+            required :model_name, String, api_name: :modelName
+
+            # @!attribute api_key
+            #   API key for the model provider
+            #
+            #   @return [String, nil]
+            optional :api_key, String, api_name: :apiKey
+
+            # @!attribute base_url
+            #   Base URL for the model provider
+            #
+            #   @return [String, nil]
+            optional :base_url, String, api_name: :baseURL
+
+            # @!attribute headers
+            #   Custom headers sent with every request to the model provider
+            #
+            #   @return [Hash{Symbol=>String}, nil]
+            optional :headers, Stagehand::Internal::Type::HashOf[String]
+
+            # @!attribute provider
+            #   AI provider for the model (or provide a baseURL endpoint instead)
+            #
+            #   @return [Symbol, Stagehand::Models::SessionExtractParams::Options::Model::GenericModelConfigObject::Provider, nil]
+            optional :provider,
+                     enum: -> { Stagehand::SessionExtractParams::Options::Model::GenericModelConfigObject::Provider }
+
+            # @!method initialize(model_name:, api_key: nil, base_url: nil, headers: nil, provider: nil)
+            #   @param model_name [String] Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            #
+            #   @param api_key [String] API key for the model provider
+            #
+            #   @param base_url [String] Base URL for the model provider
+            #
+            #   @param headers [Hash{Symbol=>String}] Custom headers sent with every request to the model provider
+            #
+            #   @param provider [Symbol, Stagehand::Models::SessionExtractParams::Options::Model::GenericModelConfigObject::Provider] AI provider for the model (or provide a baseURL endpoint instead)
+
+            # AI provider for the model (or provide a baseURL endpoint instead)
+            #
+            # @see Stagehand::Models::SessionExtractParams::Options::Model::GenericModelConfigObject#provider
+            module Provider
+              extend Stagehand::Internal::Type::Enum
+
+              OPENAI = :openai
+              ANTHROPIC = :anthropic
+              GOOGLE = :google
+              MICROSOFT = :microsoft
+              BEDROCK = :bedrock
+
+              # @!method self.values
+              #   @return [Array<Symbol>]
+            end
+          end
+
           # @!method self.variants
-          #   @return [Array(Stagehand::Models::ModelConfig, String)]
+          #   @return [Array(Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject, Stagehand::Models::SessionExtractParams::Options::Model::GenericModelConfigObject, String)]
         end
       end
 
diff --git a/lib/stagehand/models/session_observe_params.rb b/lib/stagehand/models/session_observe_params.rb
index b2c2f74..7ca65fe 100644
--- a/lib/stagehand/models/session_observe_params.rb
+++ b/lib/stagehand/models/session_observe_params.rb
@@ -52,10 +52,16 @@ class SessionObserveParams < Stagehand::Internal::Type::BaseModel
       #   @param request_options [Stagehand::RequestOptions, Hash{Symbol=>Object}]
 
       class Options < Stagehand::Internal::Type::BaseModel
+        # @!attribute ignore_selectors
+        #   Selectors for elements and subtrees that should be excluded from observation
+        #
+        #   @return [Array<String>, nil]
+        optional :ignore_selectors, Stagehand::Internal::Type::ArrayOf[String], api_name: :ignoreSelectors
+
         # @!attribute model
         #   Model configuration object or model name string (e.g., 'openai/gpt-5-nano')
         #
-        #   @return [Stagehand::Models::ModelConfig, String, nil]
+        #   @return [Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject, Stagehand::Models::SessionObserveParams::Options::Model::GenericModelConfigObject, String, nil]
         optional :model, union: -> { Stagehand::SessionObserveParams::Options::Model }
 
         # @!attribute selector
@@ -79,11 +85,13 @@ class Options < Stagehand::Internal::Type::BaseModel
         optional :variables,
                  -> { Stagehand::Internal::Type::HashOf[union: Stagehand::SessionObserveParams::Options::Variable] }
 
-        # @!method initialize(model: nil, selector: nil, timeout: nil, variables: nil)
+        # @!method initialize(ignore_selectors: nil, model: nil, selector: nil, timeout: nil, variables: nil)
         #   Some parameter documentations has been truncated, see
         #   {Stagehand::Models::SessionObserveParams::Options} for more details.
         #
-        #   @param model [Stagehand::Models::ModelConfig, String] Model configuration object or model name string (e.g., 'openai/gpt-5-nano')
+        #   @param ignore_selectors [Array<String>] Selectors for elements and subtrees that should be excluded from observation
+        #
+        #   @param model [Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject, Stagehand::Models::SessionObserveParams::Options::Model::GenericModelConfigObject, String] Model configuration object or model name string (e.g., 'openai/gpt-5-nano')
         #
         #   @param selector [String] CSS selector to scope observation to a specific element
         #
@@ -97,12 +105,339 @@ class Options < Stagehand::Internal::Type::BaseModel
         module Model
           extend Stagehand::Internal::Type::Union
 
-          variant -> { Stagehand::ModelConfig }
+          variant -> { Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject }
+
+          variant -> { Stagehand::SessionObserveParams::Options::Model::GenericModelConfigObject }
 
           variant String
 
+          class VertexModelConfigObject < Stagehand::Internal::Type::BaseModel
+            # @!attribute auth
+            #   Vertex provider authentication configuration
+            #
+            #   @return [Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth]
+            required :auth, -> { Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth }
+
+            # @!attribute model_name
+            #   Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            #
+            #   @return [String]
+            required :model_name, String, api_name: :modelName
+
+            # @!attribute provider
+            #   Vertex AI model provider
+            #
+            #   @return [Symbol, :vertex]
+            required :provider, const: :vertex
+
+            # @!attribute provider_options
+            #   Vertex provider-specific model configuration
+            #
+            #   @return [Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::ProviderOptions]
+            required :provider_options,
+                     -> {
+                       Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::ProviderOptions
+                     },
+                     api_name: :providerOptions
+
+            # @!attribute api_key
+            #   API key for the model provider
+            #
+            #   @return [String, nil]
+            optional :api_key, String, api_name: :apiKey
+
+            # @!attribute base_url
+            #   Base URL for the model provider
+            #
+            #   @return [String, nil]
+            optional :base_url, String, api_name: :baseURL
+
+            # @!attribute headers
+            #   Custom headers sent with every request to the model provider
+            #
+            #   @return [Hash{Symbol=>String}, nil]
+            optional :headers, Stagehand::Internal::Type::HashOf[String]
+
+            # @!method initialize(auth:, model_name:, provider_options:, api_key: nil, base_url: nil, headers: nil, provider: :vertex)
+            #   @param auth [Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth] Vertex provider authentication configuration
+            #
+            #   @param model_name [String] Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            #
+            #   @param provider_options [Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::ProviderOptions] Vertex provider-specific model configuration
+            #
+            #   @param api_key [String] API key for the model provider
+            #
+            #   @param base_url [String] Base URL for the model provider
+            #
+            #   @param headers [Hash{Symbol=>String}] Custom headers sent with every request to the model provider
+            #
+            #   @param provider [Symbol, :vertex] Vertex AI model provider
+
+            # @see Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject#auth
+            class Auth < Stagehand::Internal::Type::BaseModel
+              # @!attribute credentials
+              #   Google Cloud service account credentials
+              #
+              #   @return [Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials]
+              required :credentials,
+                       -> { Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials }
+
+              # @!attribute type
+              #   Use inline Google Cloud service account credentials for provider authentication
+              #
+              #   @return [Symbol, :googleServiceAccount]
+              required :type, const: :googleServiceAccount
+
+              # @!attribute project_id
+              #   Google Cloud project ID used by google-auth-library
+              #
+              #   @return [String, nil]
+              optional :project_id, String, api_name: :projectId
+
+              # @!attribute scopes
+              #   Google auth scopes for the desired API request
+              #
+              #   @return [String, Array<String>, nil]
+              optional :scopes,
+                       union: -> { Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Scopes }
+
+              # @!attribute universe_domain
+              #   Google Cloud universe domain
+              #
+              #   @return [String, nil]
+              optional :universe_domain, String, api_name: :universeDomain
+
+              # @!method initialize(credentials:, project_id: nil, scopes: nil, universe_domain: nil, type: :googleServiceAccount)
+              #   Vertex provider authentication configuration
+              #
+              #   @param credentials [Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials] Google Cloud service account credentials
+              #
+              #   @param project_id [String] Google Cloud project ID used by google-auth-library
+              #
+              #   @param scopes [String, Array<String>] Google auth scopes for the desired API request
+              #
+              #   @param universe_domain [String] Google Cloud universe domain
+              #
+              #   @param type [Symbol, :googleServiceAccount] Use inline Google Cloud service account credentials for provider authentication
+
+              # @see Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth#credentials
+              class Credentials < Stagehand::Internal::Type::BaseModel
+                # @!attribute client_email
+                #
+                #   @return [String]
+                required :client_email, String
+
+                # @!attribute private_key
+                #
+                #   @return [String]
+                required :private_key, String
+
+                # @!attribute auth_provider_x509_cert_url
+                #
+                #   @return [String, nil]
+                optional :auth_provider_x509_cert_url, String
+
+                # @!attribute auth_uri
+                #
+                #   @return [String, nil]
+                optional :auth_uri, String
+
+                # @!attribute client_id
+                #
+                #   @return [String, nil]
+                optional :client_id, String
+
+                # @!attribute client_x509_cert_url
+                #
+                #   @return [String, nil]
+                optional :client_x509_cert_url, String
+
+                # @!attribute private_key_id
+                #
+                #   @return [String, nil]
+                optional :private_key_id, String
+
+                # @!attribute project_id
+                #
+                #   @return [String, nil]
+                optional :project_id, String
+
+                # @!attribute token_uri
+                #
+                #   @return [String, nil]
+                optional :token_uri, String
+
+                # @!attribute type
+                #
+                #   @return [Symbol, Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type, nil]
+                optional :type,
+                         enum: -> { Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type }
+
+                # @!attribute universe_domain
+                #
+                #   @return [String, nil]
+                optional :universe_domain, String
+
+                # @!method initialize(client_email:, private_key:, auth_provider_x509_cert_url: nil, auth_uri: nil, client_id: nil, client_x509_cert_url: nil, private_key_id: nil, project_id: nil, token_uri: nil, type: nil, universe_domain: nil)
+                #   Google Cloud service account credentials
+                #
+                #   @param client_email [String]
+                #   @param private_key [String]
+                #   @param auth_provider_x509_cert_url [String]
+                #   @param auth_uri [String]
+                #   @param client_id [String]
+                #   @param client_x509_cert_url [String]
+                #   @param private_key_id [String]
+                #   @param project_id [String]
+                #   @param token_uri [String]
+                #   @param type [Symbol, Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type]
+                #   @param universe_domain [String]
+
+                # @see Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials#type
+                module Type
+                  extend Stagehand::Internal::Type::Enum
+
+                  SERVICE_ACCOUNT = :service_account
+
+                  # @!method self.values
+                  #   @return [Array<Symbol>]
+                end
+              end
+
+              # Google auth scopes for the desired API request
+              #
+              # @see Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth#scopes
+              module Scopes
+                extend Stagehand::Internal::Type::Union
+
+                variant String
+
+                variant -> { Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Scopes::StringArray }
+
+                # @!method self.variants
+                #   @return [Array(String, Array<String>)]
+
+                # @type [Stagehand::Internal::Type::Converter]
+                StringArray = Stagehand::Internal::Type::ArrayOf[String]
+              end
+            end
+
+            # @see Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject#provider_options
+            class ProviderOptions < Stagehand::Internal::Type::BaseModel
+              # @!attribute vertex
+              #   Vertex AI provider-specific settings
+              #
+              #   @return [Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex]
+              required :vertex,
+                       -> { Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex }
+
+              # @!method initialize(vertex:)
+              #   Vertex provider-specific model configuration
+              #
+              #   @param vertex [Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex] Vertex AI provider-specific settings
+
+              # @see Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::ProviderOptions#vertex
+              class Vertex < Stagehand::Internal::Type::BaseModel
+                # @!attribute location
+                #   Google Cloud location for Vertex AI models
+                #
+                #   @return [String]
+                required :location, String
+
+                # @!attribute project
+                #   Google Cloud project ID for Vertex AI models
+                #
+                #   @return [String]
+                required :project, String
+
+                # @!attribute base_url
+                #   Base URL for the Vertex AI provider
+                #
+                #   @return [String, nil]
+                optional :base_url, String, api_name: :baseURL
+
+                # @!attribute headers
+                #   Custom headers sent with every request to the Vertex AI provider
+                #
+                #   @return [Hash{Symbol=>String}, nil]
+                optional :headers, Stagehand::Internal::Type::HashOf[String]
+
+                # @!method initialize(location:, project:, base_url: nil, headers: nil)
+                #   Vertex AI provider-specific settings
+                #
+                #   @param location [String] Google Cloud location for Vertex AI models
+                #
+                #   @param project [String] Google Cloud project ID for Vertex AI models
+                #
+                #   @param base_url [String] Base URL for the Vertex AI provider
+                #
+                #   @param headers [Hash{Symbol=>String}] Custom headers sent with every request to the Vertex AI provider
+              end
+            end
+          end
+
+          class GenericModelConfigObject < Stagehand::Internal::Type::BaseModel
+            # @!attribute model_name
+            #   Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            #
+            #   @return [String]
+            required :model_name, String, api_name: :modelName
+
+            # @!attribute api_key
+            #   API key for the model provider
+            #
+            #   @return [String, nil]
+            optional :api_key, String, api_name: :apiKey
+
+            # @!attribute base_url
+            #   Base URL for the model provider
+            #
+            #   @return [String, nil]
+            optional :base_url, String, api_name: :baseURL
+
+            # @!attribute headers
+            #   Custom headers sent with every request to the model provider
+            #
+            #   @return [Hash{Symbol=>String}, nil]
+            optional :headers, Stagehand::Internal::Type::HashOf[String]
+
+            # @!attribute provider
+            #   AI provider for the model (or provide a baseURL endpoint instead)
+            #
+            #   @return [Symbol, Stagehand::Models::SessionObserveParams::Options::Model::GenericModelConfigObject::Provider, nil]
+            optional :provider,
+                     enum: -> { Stagehand::SessionObserveParams::Options::Model::GenericModelConfigObject::Provider }
+
+            # @!method initialize(model_name:, api_key: nil, base_url: nil, headers: nil, provider: nil)
+            #   @param model_name [String] Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            #
+            #   @param api_key [String] API key for the model provider
+            #
+            #   @param base_url [String] Base URL for the model provider
+            #
+            #   @param headers [Hash{Symbol=>String}] Custom headers sent with every request to the model provider
+            #
+            #   @param provider [Symbol, Stagehand::Models::SessionObserveParams::Options::Model::GenericModelConfigObject::Provider] AI provider for the model (or provide a baseURL endpoint instead)
+
+            # AI provider for the model (or provide a baseURL endpoint instead)
+            #
+            # @see Stagehand::Models::SessionObserveParams::Options::Model::GenericModelConfigObject#provider
+            module Provider
+              extend Stagehand::Internal::Type::Enum
+
+              OPENAI = :openai
+              ANTHROPIC = :anthropic
+              GOOGLE = :google
+              MICROSOFT = :microsoft
+              BEDROCK = :bedrock
+
+              # @!method self.values
+              #   @return [Array<Symbol>]
+            end
+          end
+
           # @!method self.variants
-          #   @return [Array(Stagehand::Models::ModelConfig, String)]
+          #   @return [Array(Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject, Stagehand::Models::SessionObserveParams::Options::Model::GenericModelConfigObject, String)]
         end
 
         module Variable
diff --git a/lib/stagehand/version.rb b/lib/stagehand/version.rb
index 2fbf718..bffebd2 100644
--- a/lib/stagehand/version.rb
+++ b/lib/stagehand/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module Stagehand
-  VERSION = "3.20.0"
+  VERSION = "3.21.0"
 end
diff --git a/rbi/stagehand/models/model_config.rbi b/rbi/stagehand/models/model_config.rbi
index 5d1bc44..d43b6d9 100644
--- a/rbi/stagehand/models/model_config.rbi
+++ b/rbi/stagehand/models/model_config.rbi
@@ -2,105 +2,680 @@
 
 module Stagehand
   module Models
-    class ModelConfig < Stagehand::Internal::Type::BaseModel
-      OrHash =
+    module ModelConfig
+      extend Stagehand::Internal::Type::Union
+
+      Variants =
         T.type_alias do
-          T.any(Stagehand::ModelConfig, Stagehand::Internal::AnyHash)
+          T.any(
+            Stagehand::ModelConfig::VertexModelConfigObject,
+            Stagehand::ModelConfig::GenericModelConfigObject
+          )
         end
 
-      # Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
-      sig { returns(String) }
-      attr_accessor :model_name
+      class VertexModelConfigObject < Stagehand::Internal::Type::BaseModel
+        OrHash =
+          T.type_alias do
+            T.any(
+              Stagehand::ModelConfig::VertexModelConfigObject,
+              Stagehand::Internal::AnyHash
+            )
+          end
 
-      # API key for the model provider
-      sig { returns(T.nilable(String)) }
-      attr_reader :api_key
+        # Vertex provider authentication configuration
+        sig { returns(Stagehand::ModelConfig::VertexModelConfigObject::Auth) }
+        attr_reader :auth
 
-      sig { params(api_key: String).void }
-      attr_writer :api_key
+        sig do
+          params(
+            auth: Stagehand::ModelConfig::VertexModelConfigObject::Auth::OrHash
+          ).void
+        end
+        attr_writer :auth
 
-      # Base URL for the model provider
-      sig { returns(T.nilable(String)) }
-      attr_reader :base_url
+        # Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+        sig { returns(String) }
+        attr_accessor :model_name
 
-      sig { params(base_url: String).void }
-      attr_writer :base_url
+        # Vertex AI model provider
+        sig { returns(Symbol) }
+        attr_accessor :provider
 
-      # Custom headers sent with every request to the model provider
-      sig { returns(T.nilable(T::Hash[Symbol, String])) }
-      attr_reader :headers
+        # Vertex provider-specific model configuration
+        sig do
+          returns(
+            Stagehand::ModelConfig::VertexModelConfigObject::ProviderOptions
+          )
+        end
+        attr_reader :provider_options
 
-      sig { params(headers: T::Hash[Symbol, String]).void }
-      attr_writer :headers
+        sig do
+          params(
+            provider_options:
+              Stagehand::ModelConfig::VertexModelConfigObject::ProviderOptions::OrHash
+          ).void
+        end
+        attr_writer :provider_options
 
-      # AI provider for the model (or provide a baseURL endpoint instead)
-      sig { returns(T.nilable(Stagehand::ModelConfig::Provider::OrSymbol)) }
-      attr_reader :provider
+        # API key for the model provider
+        sig { returns(T.nilable(String)) }
+        attr_reader :api_key
 
-      sig { params(provider: Stagehand::ModelConfig::Provider::OrSymbol).void }
-      attr_writer :provider
+        sig { params(api_key: String).void }
+        attr_writer :api_key
 
-      sig do
-        params(
-          model_name: String,
-          api_key: String,
-          base_url: String,
-          headers: T::Hash[Symbol, String],
-          provider: Stagehand::ModelConfig::Provider::OrSymbol
-        ).returns(T.attached_class)
-      end
-      def self.new(
-        # Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
-        model_name:,
-        # API key for the model provider
-        api_key: nil,
         # Base URL for the model provider
-        base_url: nil,
+        sig { returns(T.nilable(String)) }
+        attr_reader :base_url
+
+        sig { params(base_url: String).void }
+        attr_writer :base_url
+
         # Custom headers sent with every request to the model provider
-        headers: nil,
-        # AI provider for the model (or provide a baseURL endpoint instead)
-        provider: nil
-      )
-      end
+        sig { returns(T.nilable(T::Hash[Symbol, String])) }
+        attr_reader :headers
 
-      sig do
-        override.returns(
-          {
+        sig { params(headers: T::Hash[Symbol, String]).void }
+        attr_writer :headers
+
+        sig do
+          params(
+            auth: Stagehand::ModelConfig::VertexModelConfigObject::Auth::OrHash,
             model_name: String,
+            provider_options:
+              Stagehand::ModelConfig::VertexModelConfigObject::ProviderOptions::OrHash,
             api_key: String,
             base_url: String,
             headers: T::Hash[Symbol, String],
-            provider: Stagehand::ModelConfig::Provider::OrSymbol
-          }
+            provider: Symbol
+          ).returns(T.attached_class)
+        end
+        def self.new(
+          # Vertex provider authentication configuration
+          auth:,
+          # Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+          model_name:,
+          # Vertex provider-specific model configuration
+          provider_options:,
+          # API key for the model provider
+          api_key: nil,
+          # Base URL for the model provider
+          base_url: nil,
+          # Custom headers sent with every request to the model provider
+          headers: nil,
+          # Vertex AI model provider
+          provider: :vertex
         )
+        end
+
+        sig do
+          override.returns(
+            {
+              auth: Stagehand::ModelConfig::VertexModelConfigObject::Auth,
+              model_name: String,
+              provider: Symbol,
+              provider_options:
+                Stagehand::ModelConfig::VertexModelConfigObject::ProviderOptions,
+              api_key: String,
+              base_url: String,
+              headers: T::Hash[Symbol, String]
+            }
+          )
+        end
+        def to_hash
+        end
+
+        class Auth < Stagehand::Internal::Type::BaseModel
+          OrHash =
+            T.type_alias do
+              T.any(
+                Stagehand::ModelConfig::VertexModelConfigObject::Auth,
+                Stagehand::Internal::AnyHash
+              )
+            end
+
+          # Google Cloud service account credentials
+          sig do
+            returns(
+              Stagehand::ModelConfig::VertexModelConfigObject::Auth::Credentials
+            )
+          end
+          attr_reader :credentials
+
+          sig do
+            params(
+              credentials:
+                Stagehand::ModelConfig::VertexModelConfigObject::Auth::Credentials::OrHash
+            ).void
+          end
+          attr_writer :credentials
+
+          # Use inline Google Cloud service account credentials for provider authentication
+          sig { returns(Symbol) }
+          attr_accessor :type
+
+          # Google Cloud project ID used by google-auth-library
+          sig { returns(T.nilable(String)) }
+          attr_reader :project_id
+
+          sig { params(project_id: String).void }
+          attr_writer :project_id
+
+          # Google auth scopes for the desired API request
+          sig do
+            returns(
+              T.nilable(
+                Stagehand::ModelConfig::VertexModelConfigObject::Auth::Scopes::Variants
+              )
+            )
+          end
+          attr_reader :scopes
+
+          sig do
+            params(
+              scopes:
+                Stagehand::ModelConfig::VertexModelConfigObject::Auth::Scopes::Variants
+            ).void
+          end
+          attr_writer :scopes
+
+          # Google Cloud universe domain
+          sig { returns(T.nilable(String)) }
+          attr_reader :universe_domain
+
+          sig { params(universe_domain: String).void }
+          attr_writer :universe_domain
+
+          # Vertex provider authentication configuration
+          sig do
+            params(
+              credentials:
+                Stagehand::ModelConfig::VertexModelConfigObject::Auth::Credentials::OrHash,
+              project_id: String,
+              scopes:
+                Stagehand::ModelConfig::VertexModelConfigObject::Auth::Scopes::Variants,
+              universe_domain: String,
+              type: Symbol
+            ).returns(T.attached_class)
+          end
+          def self.new(
+            # Google Cloud service account credentials
+            credentials:,
+            # Google Cloud project ID used by google-auth-library
+            project_id: nil,
+            # Google auth scopes for the desired API request
+            scopes: nil,
+            # Google Cloud universe domain
+            universe_domain: nil,
+            # Use inline Google Cloud service account credentials for provider authentication
+            type: :googleServiceAccount
+          )
+          end
+
+          sig do
+            override.returns(
+              {
+                credentials:
+                  Stagehand::ModelConfig::VertexModelConfigObject::Auth::Credentials,
+                type: Symbol,
+                project_id: String,
+                scopes:
+                  Stagehand::ModelConfig::VertexModelConfigObject::Auth::Scopes::Variants,
+                universe_domain: String
+              }
+            )
+          end
+          def to_hash
+          end
+
+          class Credentials < Stagehand::Internal::Type::BaseModel
+            OrHash =
+              T.type_alias do
+                T.any(
+                  Stagehand::ModelConfig::VertexModelConfigObject::Auth::Credentials,
+                  Stagehand::Internal::AnyHash
+                )
+              end
+
+            sig { returns(String) }
+            attr_accessor :client_email
+
+            sig { returns(String) }
+            attr_accessor :private_key
+
+            sig { returns(T.nilable(String)) }
+            attr_reader :auth_provider_x509_cert_url
+
+            sig { params(auth_provider_x509_cert_url: String).void }
+            attr_writer :auth_provider_x509_cert_url
+
+            sig { returns(T.nilable(String)) }
+            attr_reader :auth_uri
+
+            sig { params(auth_uri: String).void }
+            attr_writer :auth_uri
+
+            sig { returns(T.nilable(String)) }
+            attr_reader :client_id
+
+            sig { params(client_id: String).void }
+            attr_writer :client_id
+
+            sig { returns(T.nilable(String)) }
+            attr_reader :client_x509_cert_url
+
+            sig { params(client_x509_cert_url: String).void }
+            attr_writer :client_x509_cert_url
+
+            sig { returns(T.nilable(String)) }
+            attr_reader :private_key_id
+
+            sig { params(private_key_id: String).void }
+            attr_writer :private_key_id
+
+            sig { returns(T.nilable(String)) }
+            attr_reader :project_id
+
+            sig { params(project_id: String).void }
+            attr_writer :project_id
+
+            sig { returns(T.nilable(String)) }
+            attr_reader :token_uri
+
+            sig { params(token_uri: String).void }
+            attr_writer :token_uri
+
+            sig do
+              returns(
+                T.nilable(
+                  Stagehand::ModelConfig::VertexModelConfigObject::Auth::Credentials::Type::OrSymbol
+                )
+              )
+            end
+            attr_reader :type
+
+            sig do
+              params(
+                type:
+                  Stagehand::ModelConfig::VertexModelConfigObject::Auth::Credentials::Type::OrSymbol
+              ).void
+            end
+            attr_writer :type
+
+            sig { returns(T.nilable(String)) }
+            attr_reader :universe_domain
+
+            sig { params(universe_domain: String).void }
+            attr_writer :universe_domain
+
+            # Google Cloud service account credentials
+            sig do
+              params(
+                client_email: String,
+                private_key: String,
+                auth_provider_x509_cert_url: String,
+                auth_uri: String,
+                client_id: String,
+                client_x509_cert_url: String,
+                private_key_id: String,
+                project_id: String,
+                token_uri: String,
+                type:
+                  Stagehand::ModelConfig::VertexModelConfigObject::Auth::Credentials::Type::OrSymbol,
+                universe_domain: String
+              ).returns(T.attached_class)
+            end
+            def self.new(
+              client_email:,
+              private_key:,
+              auth_provider_x509_cert_url: nil,
+              auth_uri: nil,
+              client_id: nil,
+              client_x509_cert_url: nil,
+              private_key_id: nil,
+              project_id: nil,
+              token_uri: nil,
+              type: nil,
+              universe_domain: nil
+            )
+            end
+
+            sig do
+              override.returns(
+                {
+                  client_email: String,
+                  private_key: String,
+                  auth_provider_x509_cert_url: String,
+                  auth_uri: String,
+                  client_id: String,
+                  client_x509_cert_url: String,
+                  private_key_id: String,
+                  project_id: String,
+                  token_uri: String,
+                  type:
+                    Stagehand::ModelConfig::VertexModelConfigObject::Auth::Credentials::Type::OrSymbol,
+                  universe_domain: String
+                }
+              )
+            end
+            def to_hash
+            end
+
+            module Type
+              extend Stagehand::Internal::Type::Enum
+
+              TaggedSymbol =
+                T.type_alias do
+                  T.all(
+                    Symbol,
+                    Stagehand::ModelConfig::VertexModelConfigObject::Auth::Credentials::Type
+                  )
+                end
+              OrSymbol = T.type_alias { T.any(Symbol, String) }
+
+              SERVICE_ACCOUNT =
+                T.let(
+                  :service_account,
+                  Stagehand::ModelConfig::VertexModelConfigObject::Auth::Credentials::Type::TaggedSymbol
+                )
+
+              sig do
+                override.returns(
+                  T::Array[
+                    Stagehand::ModelConfig::VertexModelConfigObject::Auth::Credentials::Type::TaggedSymbol
+                  ]
+                )
+              end
+              def self.values
+              end
+            end
+          end
+
+          # Google auth scopes for the desired API request
+          module Scopes
+            extend Stagehand::Internal::Type::Union
+
+            Variants = T.type_alias { T.any(String, T::Array[String]) }
+
+            sig do
+              override.returns(
+                T::Array[
+                  Stagehand::ModelConfig::VertexModelConfigObject::Auth::Scopes::Variants
+                ]
+              )
+            end
+            def self.variants
+            end
+
+            StringArray =
+              T.let(
+                Stagehand::Internal::Type::ArrayOf[String],
+                Stagehand::Internal::Type::Converter
+              )
+          end
+        end
+
+        class ProviderOptions < Stagehand::Internal::Type::BaseModel
+          OrHash =
+            T.type_alias do
+              T.any(
+                Stagehand::ModelConfig::VertexModelConfigObject::ProviderOptions,
+                Stagehand::Internal::AnyHash
+              )
+            end
+
+          # Vertex AI provider-specific settings
+          sig do
+            returns(
+              Stagehand::ModelConfig::VertexModelConfigObject::ProviderOptions::Vertex
+            )
+          end
+          attr_reader :vertex
+
+          sig do
+            params(
+              vertex:
+                Stagehand::ModelConfig::VertexModelConfigObject::ProviderOptions::Vertex::OrHash
+            ).void
+          end
+          attr_writer :vertex
+
+          # Vertex provider-specific model configuration
+          sig do
+            params(
+              vertex:
+                Stagehand::ModelConfig::VertexModelConfigObject::ProviderOptions::Vertex::OrHash
+            ).returns(T.attached_class)
+          end
+          def self.new(
+            # Vertex AI provider-specific settings
+            vertex:
+          )
+          end
+
+          sig do
+            override.returns(
+              {
+                vertex:
+                  Stagehand::ModelConfig::VertexModelConfigObject::ProviderOptions::Vertex
+              }
+            )
+          end
+          def to_hash
+          end
+
+          class Vertex < Stagehand::Internal::Type::BaseModel
+            OrHash =
+              T.type_alias do
+                T.any(
+                  Stagehand::ModelConfig::VertexModelConfigObject::ProviderOptions::Vertex,
+                  Stagehand::Internal::AnyHash
+                )
+              end
+
+            # Google Cloud location for Vertex AI models
+            sig { returns(String) }
+            attr_accessor :location
+
+            # Google Cloud project ID for Vertex AI models
+            sig { returns(String) }
+            attr_accessor :project
+
+            # Base URL for the Vertex AI provider
+            sig { returns(T.nilable(String)) }
+            attr_reader :base_url
+
+            sig { params(base_url: String).void }
+            attr_writer :base_url
+
+            # Custom headers sent with every request to the Vertex AI provider
+            sig { returns(T.nilable(T::Hash[Symbol, String])) }
+            attr_reader :headers
+
+            sig { params(headers: T::Hash[Symbol, String]).void }
+            attr_writer :headers
+
+            # Vertex AI provider-specific settings
+            sig do
+              params(
+                location: String,
+                project: String,
+                base_url: String,
+                headers: T::Hash[Symbol, String]
+              ).returns(T.attached_class)
+            end
+            def self.new(
+              # Google Cloud location for Vertex AI models
+              location:,
+              # Google Cloud project ID for Vertex AI models
+              project:,
+              # Base URL for the Vertex AI provider
+              base_url: nil,
+              # Custom headers sent with every request to the Vertex AI provider
+              headers: nil
+            )
+            end
+
+            sig do
+              override.returns(
+                {
+                  location: String,
+                  project: String,
+                  base_url: String,
+                  headers: T::Hash[Symbol, String]
+                }
+              )
+            end
+            def to_hash
+            end
+          end
+        end
       end
-      def to_hash
-      end
 
-      # AI provider for the model (or provide a baseURL endpoint instead)
-      module Provider
-        extend Stagehand::Internal::Type::Enum
+      class GenericModelConfigObject < Stagehand::Internal::Type::BaseModel
+        OrHash =
+          T.type_alias do
+            T.any(
+              Stagehand::ModelConfig::GenericModelConfigObject,
+              Stagehand::Internal::AnyHash
+            )
+          end
+
+        # Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+        sig { returns(String) }
+        attr_accessor :model_name
+
+        # API key for the model provider
+        sig { returns(T.nilable(String)) }
+        attr_reader :api_key
+
+        sig { params(api_key: String).void }
+        attr_writer :api_key
+
+        # Base URL for the model provider
+        sig { returns(T.nilable(String)) }
+        attr_reader :base_url
+
+        sig { params(base_url: String).void }
+        attr_writer :base_url
+
+        # Custom headers sent with every request to the model provider
+        sig { returns(T.nilable(T::Hash[Symbol, String])) }
+        attr_reader :headers
+
+        sig { params(headers: T::Hash[Symbol, String]).void }
+        attr_writer :headers
 
-        TaggedSymbol =
-          T.type_alias { T.all(Symbol, Stagehand::ModelConfig::Provider) }
-        OrSymbol = T.type_alias { T.any(Symbol, String) }
+        # AI provider for the model (or provide a baseURL endpoint instead)
+        sig do
+          returns(
+            T.nilable(
+              Stagehand::ModelConfig::GenericModelConfigObject::Provider::OrSymbol
+            )
+          )
+        end
+        attr_reader :provider
 
-        OPENAI = T.let(:openai, Stagehand::ModelConfig::Provider::TaggedSymbol)
-        ANTHROPIC =
-          T.let(:anthropic, Stagehand::ModelConfig::Provider::TaggedSymbol)
-        GOOGLE = T.let(:google, Stagehand::ModelConfig::Provider::TaggedSymbol)
-        MICROSOFT =
-          T.let(:microsoft, Stagehand::ModelConfig::Provider::TaggedSymbol)
-        BEDROCK =
-          T.let(:bedrock, Stagehand::ModelConfig::Provider::TaggedSymbol)
+        sig do
+          params(
+            provider:
+              Stagehand::ModelConfig::GenericModelConfigObject::Provider::OrSymbol
+          ).void
+        end
+        attr_writer :provider
+
+        sig do
+          params(
+            model_name: String,
+            api_key: String,
+            base_url: String,
+            headers: T::Hash[Symbol, String],
+            provider:
+              Stagehand::ModelConfig::GenericModelConfigObject::Provider::OrSymbol
+          ).returns(T.attached_class)
+        end
+        def self.new(
+          # Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+          model_name:,
+          # API key for the model provider
+          api_key: nil,
+          # Base URL for the model provider
+          base_url: nil,
+          # Custom headers sent with every request to the model provider
+          headers: nil,
+          # AI provider for the model (or provide a baseURL endpoint instead)
+          provider: nil
+        )
+        end
 
         sig do
           override.returns(
-            T::Array[Stagehand::ModelConfig::Provider::TaggedSymbol]
+            {
+              model_name: String,
+              api_key: String,
+              base_url: String,
+              headers: T::Hash[Symbol, String],
+              provider:
+                Stagehand::ModelConfig::GenericModelConfigObject::Provider::OrSymbol
+            }
           )
         end
-        def self.values
+        def to_hash
         end
+
+        # AI provider for the model (or provide a baseURL endpoint instead)
+        module Provider
+          extend Stagehand::Internal::Type::Enum
+
+          TaggedSymbol =
+            T.type_alias do
+              T.all(
+                Symbol,
+                Stagehand::ModelConfig::GenericModelConfigObject::Provider
+              )
+            end
+          OrSymbol = T.type_alias { T.any(Symbol, String) }
+
+          OPENAI =
+            T.let(
+              :openai,
+              Stagehand::ModelConfig::GenericModelConfigObject::Provider::TaggedSymbol
+            )
+          ANTHROPIC =
+            T.let(
+              :anthropic,
+              Stagehand::ModelConfig::GenericModelConfigObject::Provider::TaggedSymbol
+            )
+          GOOGLE =
+            T.let(
+              :google,
+              Stagehand::ModelConfig::GenericModelConfigObject::Provider::TaggedSymbol
+            )
+          MICROSOFT =
+            T.let(
+              :microsoft,
+              Stagehand::ModelConfig::GenericModelConfigObject::Provider::TaggedSymbol
+            )
+          BEDROCK =
+            T.let(
+              :bedrock,
+              Stagehand::ModelConfig::GenericModelConfigObject::Provider::TaggedSymbol
+            )
+
+          sig do
+            override.returns(
+              T::Array[
+                Stagehand::ModelConfig::GenericModelConfigObject::Provider::TaggedSymbol
+              ]
+            )
+          end
+          def self.values
+          end
+        end
+      end
+
+      sig { override.returns(T::Array[Stagehand::ModelConfig::Variants]) }
+      def self.variants
       end
     end
   end
diff --git a/rbi/stagehand/models/session_act_params.rbi b/rbi/stagehand/models/session_act_params.rbi
index 79e22a8..81b2454 100644
--- a/rbi/stagehand/models/session_act_params.rbi
+++ b/rbi/stagehand/models/session_act_params.rbi
@@ -111,11 +111,28 @@ module Stagehand
           end
 
         # Model configuration object or model name string (e.g., 'openai/gpt-5-nano')
-        sig { returns(T.nilable(T.any(Stagehand::ModelConfig, String))) }
+        sig do
+          returns(
+            T.nilable(
+              T.any(
+                Stagehand::SessionActParams::Options::Model::VertexModelConfigObject,
+                Stagehand::SessionActParams::Options::Model::GenericModelConfigObject,
+                String
+              )
+            )
+          )
+        end
         attr_reader :model
 
         sig do
-          params(model: T.any(Stagehand::ModelConfig::OrHash, String)).void
+          params(
+            model:
+              T.any(
+                Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::OrHash,
+                Stagehand::SessionActParams::Options::Model::GenericModelConfigObject::OrHash,
+                String
+              )
+          ).void
         end
         attr_writer :model
 
@@ -163,7 +180,12 @@ module Stagehand
 
         sig do
           params(
-            model: T.any(Stagehand::ModelConfig::OrHash, String),
+            model:
+              T.any(
+                Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::OrHash,
+                Stagehand::SessionActParams::Options::Model::GenericModelConfigObject::OrHash,
+                String
+              ),
             timeout: Float,
             variables:
               T::Hash[
@@ -191,7 +213,12 @@ module Stagehand
         sig do
           override.returns(
             {
-              model: T.any(Stagehand::ModelConfig, String),
+              model:
+                T.any(
+                  Stagehand::SessionActParams::Options::Model::VertexModelConfigObject,
+                  Stagehand::SessionActParams::Options::Model::GenericModelConfigObject,
+                  String
+                ),
               timeout: Float,
               variables:
                 T::Hash[
@@ -213,7 +240,682 @@ module Stagehand
         module Model
           extend Stagehand::Internal::Type::Union
 
-          Variants = T.type_alias { T.any(Stagehand::ModelConfig, String) }
+          Variants =
+            T.type_alias do
+              T.any(
+                Stagehand::SessionActParams::Options::Model::VertexModelConfigObject,
+                Stagehand::SessionActParams::Options::Model::GenericModelConfigObject,
+                String
+              )
+            end
+
+          class VertexModelConfigObject < Stagehand::Internal::Type::BaseModel
+            OrHash =
+              T.type_alias do
+                T.any(
+                  Stagehand::SessionActParams::Options::Model::VertexModelConfigObject,
+                  Stagehand::Internal::AnyHash
+                )
+              end
+
+            # Vertex provider authentication configuration
+            sig do
+              returns(
+                Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth
+              )
+            end
+            attr_reader :auth
+
+            sig do
+              params(
+                auth:
+                  Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth::OrHash
+              ).void
+            end
+            attr_writer :auth
+
+            # Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            sig { returns(String) }
+            attr_accessor :model_name
+
+            # Vertex AI model provider
+            sig { returns(Symbol) }
+            attr_accessor :provider
+
+            # Vertex provider-specific model configuration
+            sig do
+              returns(
+                Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::ProviderOptions
+              )
+            end
+            attr_reader :provider_options
+
+            sig do
+              params(
+                provider_options:
+                  Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::ProviderOptions::OrHash
+              ).void
+            end
+            attr_writer :provider_options
+
+            # API key for the model provider
+            sig { returns(T.nilable(String)) }
+            attr_reader :api_key
+
+            sig { params(api_key: String).void }
+            attr_writer :api_key
+
+            # Base URL for the model provider
+            sig { returns(T.nilable(String)) }
+            attr_reader :base_url
+
+            sig { params(base_url: String).void }
+            attr_writer :base_url
+
+            # Custom headers sent with every request to the model provider
+            sig { returns(T.nilable(T::Hash[Symbol, String])) }
+            attr_reader :headers
+
+            sig { params(headers: T::Hash[Symbol, String]).void }
+            attr_writer :headers
+
+            sig do
+              params(
+                auth:
+                  Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth::OrHash,
+                model_name: String,
+                provider_options:
+                  Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::ProviderOptions::OrHash,
+                api_key: String,
+                base_url: String,
+                headers: T::Hash[Symbol, String],
+                provider: Symbol
+              ).returns(T.attached_class)
+            end
+            def self.new(
+              # Vertex provider authentication configuration
+              auth:,
+              # Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+              model_name:,
+              # Vertex provider-specific model configuration
+              provider_options:,
+              # API key for the model provider
+              api_key: nil,
+              # Base URL for the model provider
+              base_url: nil,
+              # Custom headers sent with every request to the model provider
+              headers: nil,
+              # Vertex AI model provider
+              provider: :vertex
+            )
+            end
+
+            sig do
+              override.returns(
+                {
+                  auth:
+                    Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth,
+                  model_name: String,
+                  provider: Symbol,
+                  provider_options:
+                    Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::ProviderOptions,
+                  api_key: String,
+                  base_url: String,
+                  headers: T::Hash[Symbol, String]
+                }
+              )
+            end
+            def to_hash
+            end
+
+            class Auth < Stagehand::Internal::Type::BaseModel
+              OrHash =
+                T.type_alias do
+                  T.any(
+                    Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth,
+                    Stagehand::Internal::AnyHash
+                  )
+                end
+
+              # Google Cloud service account credentials
+              sig do
+                returns(
+                  Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials
+                )
+              end
+              attr_reader :credentials
+
+              sig do
+                params(
+                  credentials:
+                    Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials::OrHash
+                ).void
+              end
+              attr_writer :credentials
+
+              # Use inline Google Cloud service account credentials for provider authentication
+              sig { returns(Symbol) }
+              attr_accessor :type
+
+              # Google Cloud project ID used by google-auth-library
+              sig { returns(T.nilable(String)) }
+              attr_reader :project_id
+
+              sig { params(project_id: String).void }
+              attr_writer :project_id
+
+              # Google auth scopes for the desired API request
+              sig do
+                returns(
+                  T.nilable(
+                    Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Scopes::Variants
+                  )
+                )
+              end
+              attr_reader :scopes
+
+              sig do
+                params(
+                  scopes:
+                    Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Scopes::Variants
+                ).void
+              end
+              attr_writer :scopes
+
+              # Google Cloud universe domain
+              sig { returns(T.nilable(String)) }
+              attr_reader :universe_domain
+
+              sig { params(universe_domain: String).void }
+              attr_writer :universe_domain
+
+              # Vertex provider authentication configuration
+              sig do
+                params(
+                  credentials:
+                    Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials::OrHash,
+                  project_id: String,
+                  scopes:
+                    Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Scopes::Variants,
+                  universe_domain: String,
+                  type: Symbol
+                ).returns(T.attached_class)
+              end
+              def self.new(
+                # Google Cloud service account credentials
+                credentials:,
+                # Google Cloud project ID used by google-auth-library
+                project_id: nil,
+                # Google auth scopes for the desired API request
+                scopes: nil,
+                # Google Cloud universe domain
+                universe_domain: nil,
+                # Use inline Google Cloud service account credentials for provider authentication
+                type: :googleServiceAccount
+              )
+              end
+
+              sig do
+                override.returns(
+                  {
+                    credentials:
+                      Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials,
+                    type: Symbol,
+                    project_id: String,
+                    scopes:
+                      Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Scopes::Variants,
+                    universe_domain: String
+                  }
+                )
+              end
+              def to_hash
+              end
+
+              class Credentials < Stagehand::Internal::Type::BaseModel
+                OrHash =
+                  T.type_alias do
+                    T.any(
+                      Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials,
+                      Stagehand::Internal::AnyHash
+                    )
+                  end
+
+                sig { returns(String) }
+                attr_accessor :client_email
+
+                sig { returns(String) }
+                attr_accessor :private_key
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :auth_provider_x509_cert_url
+
+                sig { params(auth_provider_x509_cert_url: String).void }
+                attr_writer :auth_provider_x509_cert_url
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :auth_uri
+
+                sig { params(auth_uri: String).void }
+                attr_writer :auth_uri
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :client_id
+
+                sig { params(client_id: String).void }
+                attr_writer :client_id
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :client_x509_cert_url
+
+                sig { params(client_x509_cert_url: String).void }
+                attr_writer :client_x509_cert_url
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :private_key_id
+
+                sig { params(private_key_id: String).void }
+                attr_writer :private_key_id
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :project_id
+
+                sig { params(project_id: String).void }
+                attr_writer :project_id
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :token_uri
+
+                sig { params(token_uri: String).void }
+                attr_writer :token_uri
+
+                sig do
+                  returns(
+                    T.nilable(
+                      Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type::OrSymbol
+                    )
+                  )
+                end
+                attr_reader :type
+
+                sig do
+                  params(
+                    type:
+                      Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type::OrSymbol
+                  ).void
+                end
+                attr_writer :type
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :universe_domain
+
+                sig { params(universe_domain: String).void }
+                attr_writer :universe_domain
+
+                # Google Cloud service account credentials
+                sig do
+                  params(
+                    client_email: String,
+                    private_key: String,
+                    auth_provider_x509_cert_url: String,
+                    auth_uri: String,
+                    client_id: String,
+                    client_x509_cert_url: String,
+                    private_key_id: String,
+                    project_id: String,
+                    token_uri: String,
+                    type:
+                      Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type::OrSymbol,
+                    universe_domain: String
+                  ).returns(T.attached_class)
+                end
+                def self.new(
+                  client_email:,
+                  private_key:,
+                  auth_provider_x509_cert_url: nil,
+                  auth_uri: nil,
+                  client_id: nil,
+                  client_x509_cert_url: nil,
+                  private_key_id: nil,
+                  project_id: nil,
+                  token_uri: nil,
+                  type: nil,
+                  universe_domain: nil
+                )
+                end
+
+                sig do
+                  override.returns(
+                    {
+                      client_email: String,
+                      private_key: String,
+                      auth_provider_x509_cert_url: String,
+                      auth_uri: String,
+                      client_id: String,
+                      client_x509_cert_url: String,
+                      private_key_id: String,
+                      project_id: String,
+                      token_uri: String,
+                      type:
+                        Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type::OrSymbol,
+                      universe_domain: String
+                    }
+                  )
+                end
+                def to_hash
+                end
+
+                module Type
+                  extend Stagehand::Internal::Type::Enum
+
+                  TaggedSymbol =
+                    T.type_alias do
+                      T.all(
+                        Symbol,
+                        Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type
+                      )
+                    end
+                  OrSymbol = T.type_alias { T.any(Symbol, String) }
+
+                  SERVICE_ACCOUNT =
+                    T.let(
+                      :service_account,
+                      Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type::TaggedSymbol
+                    )
+
+                  sig do
+                    override.returns(
+                      T::Array[
+                        Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type::TaggedSymbol
+                      ]
+                    )
+                  end
+                  def self.values
+                  end
+                end
+              end
+
+              # Google auth scopes for the desired API request
+              module Scopes
+                extend Stagehand::Internal::Type::Union
+
+                Variants = T.type_alias { T.any(String, T::Array[String]) }
+
+                sig do
+                  override.returns(
+                    T::Array[
+                      Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Scopes::Variants
+                    ]
+                  )
+                end
+                def self.variants
+                end
+
+                StringArray =
+                  T.let(
+                    Stagehand::Internal::Type::ArrayOf[String],
+                    Stagehand::Internal::Type::Converter
+                  )
+              end
+            end
+
+            class ProviderOptions < Stagehand::Internal::Type::BaseModel
+              OrHash =
+                T.type_alias do
+                  T.any(
+                    Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::ProviderOptions,
+                    Stagehand::Internal::AnyHash
+                  )
+                end
+
+              # Vertex AI provider-specific settings
+              sig do
+                returns(
+                  Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex
+                )
+              end
+              attr_reader :vertex
+
+              sig do
+                params(
+                  vertex:
+                    Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex::OrHash
+                ).void
+              end
+              attr_writer :vertex
+
+              # Vertex provider-specific model configuration
+              sig do
+                params(
+                  vertex:
+                    Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex::OrHash
+                ).returns(T.attached_class)
+              end
+              def self.new(
+                # Vertex AI provider-specific settings
+                vertex:
+              )
+              end
+
+              sig do
+                override.returns(
+                  {
+                    vertex:
+                      Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex
+                  }
+                )
+              end
+              def to_hash
+              end
+
+              class Vertex < Stagehand::Internal::Type::BaseModel
+                OrHash =
+                  T.type_alias do
+                    T.any(
+                      Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex,
+                      Stagehand::Internal::AnyHash
+                    )
+                  end
+
+                # Google Cloud location for Vertex AI models
+                sig { returns(String) }
+                attr_accessor :location
+
+                # Google Cloud project ID for Vertex AI models
+                sig { returns(String) }
+                attr_accessor :project
+
+                # Base URL for the Vertex AI provider
+                sig { returns(T.nilable(String)) }
+                attr_reader :base_url
+
+                sig { params(base_url: String).void }
+                attr_writer :base_url
+
+                # Custom headers sent with every request to the Vertex AI provider
+                sig { returns(T.nilable(T::Hash[Symbol, String])) }
+                attr_reader :headers
+
+                sig { params(headers: T::Hash[Symbol, String]).void }
+                attr_writer :headers
+
+                # Vertex AI provider-specific settings
+                sig do
+                  params(
+                    location: String,
+                    project: String,
+                    base_url: String,
+                    headers: T::Hash[Symbol, String]
+                  ).returns(T.attached_class)
+                end
+                def self.new(
+                  # Google Cloud location for Vertex AI models
+                  location:,
+                  # Google Cloud project ID for Vertex AI models
+                  project:,
+                  # Base URL for the Vertex AI provider
+                  base_url: nil,
+                  # Custom headers sent with every request to the Vertex AI provider
+                  headers: nil
+                )
+                end
+
+                sig do
+                  override.returns(
+                    {
+                      location: String,
+                      project: String,
+                      base_url: String,
+                      headers: T::Hash[Symbol, String]
+                    }
+                  )
+                end
+                def to_hash
+                end
+              end
+            end
+          end
+
+          class GenericModelConfigObject < Stagehand::Internal::Type::BaseModel
+            OrHash =
+              T.type_alias do
+                T.any(
+                  Stagehand::SessionActParams::Options::Model::GenericModelConfigObject,
+                  Stagehand::Internal::AnyHash
+                )
+              end
+
+            # Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            sig { returns(String) }
+            attr_accessor :model_name
+
+            # API key for the model provider
+            sig { returns(T.nilable(String)) }
+            attr_reader :api_key
+
+            sig { params(api_key: String).void }
+            attr_writer :api_key
+
+            # Base URL for the model provider
+            sig { returns(T.nilable(String)) }
+            attr_reader :base_url
+
+            sig { params(base_url: String).void }
+            attr_writer :base_url
+
+            # Custom headers sent with every request to the model provider
+            sig { returns(T.nilable(T::Hash[Symbol, String])) }
+            attr_reader :headers
+
+            sig { params(headers: T::Hash[Symbol, String]).void }
+            attr_writer :headers
+
+            # AI provider for the model (or provide a baseURL endpoint instead)
+            sig do
+              returns(
+                T.nilable(
+                  Stagehand::SessionActParams::Options::Model::GenericModelConfigObject::Provider::OrSymbol
+                )
+              )
+            end
+            attr_reader :provider
+
+            sig do
+              params(
+                provider:
+                  Stagehand::SessionActParams::Options::Model::GenericModelConfigObject::Provider::OrSymbol
+              ).void
+            end
+            attr_writer :provider
+
+            sig do
+              params(
+                model_name: String,
+                api_key: String,
+                base_url: String,
+                headers: T::Hash[Symbol, String],
+                provider:
+                  Stagehand::SessionActParams::Options::Model::GenericModelConfigObject::Provider::OrSymbol
+              ).returns(T.attached_class)
+            end
+            def self.new(
+              # Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+              model_name:,
+              # API key for the model provider
+              api_key: nil,
+              # Base URL for the model provider
+              base_url: nil,
+              # Custom headers sent with every request to the model provider
+              headers: nil,
+              # AI provider for the model (or provide a baseURL endpoint instead)
+              provider: nil
+            )
+            end
+
+            sig do
+              override.returns(
+                {
+                  model_name: String,
+                  api_key: String,
+                  base_url: String,
+                  headers: T::Hash[Symbol, String],
+                  provider:
+                    Stagehand::SessionActParams::Options::Model::GenericModelConfigObject::Provider::OrSymbol
+                }
+              )
+            end
+            def to_hash
+            end
+
+            # AI provider for the model (or provide a baseURL endpoint instead)
+            module Provider
+              extend Stagehand::Internal::Type::Enum
+
+              TaggedSymbol =
+                T.type_alias do
+                  T.all(
+                    Symbol,
+                    Stagehand::SessionActParams::Options::Model::GenericModelConfigObject::Provider
+                  )
+                end
+              OrSymbol = T.type_alias { T.any(Symbol, String) }
+
+              OPENAI =
+                T.let(
+                  :openai,
+                  Stagehand::SessionActParams::Options::Model::GenericModelConfigObject::Provider::TaggedSymbol
+                )
+              ANTHROPIC =
+                T.let(
+                  :anthropic,
+                  Stagehand::SessionActParams::Options::Model::GenericModelConfigObject::Provider::TaggedSymbol
+                )
+              GOOGLE =
+                T.let(
+                  :google,
+                  Stagehand::SessionActParams::Options::Model::GenericModelConfigObject::Provider::TaggedSymbol
+                )
+              MICROSOFT =
+                T.let(
+                  :microsoft,
+                  Stagehand::SessionActParams::Options::Model::GenericModelConfigObject::Provider::TaggedSymbol
+                )
+              BEDROCK =
+                T.let(
+                  :bedrock,
+                  Stagehand::SessionActParams::Options::Model::GenericModelConfigObject::Provider::TaggedSymbol
+                )
+
+              sig do
+                override.returns(
+                  T::Array[
+                    Stagehand::SessionActParams::Options::Model::GenericModelConfigObject::Provider::TaggedSymbol
+                  ]
+                )
+              end
+              def self.values
+              end
+            end
+          end
 
           sig do
             override.returns(
diff --git a/rbi/stagehand/models/session_execute_params.rbi b/rbi/stagehand/models/session_execute_params.rbi
index 4fafc4d..ed8174c 100644
--- a/rbi/stagehand/models/session_execute_params.rbi
+++ b/rbi/stagehand/models/session_execute_params.rbi
@@ -128,12 +128,27 @@ module Stagehand
         # Model configuration object or model name string (e.g., 'openai/gpt-5-nano') for
         # tool execution (observe/act calls within agent tools). If not specified,
         # inherits from the main model configuration.
-        sig { returns(T.nilable(T.any(Stagehand::ModelConfig, String))) }
+        sig do
+          returns(
+            T.nilable(
+              T.any(
+                Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject,
+                Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject,
+                String
+              )
+            )
+          )
+        end
         attr_reader :execution_model
 
         sig do
           params(
-            execution_model: T.any(Stagehand::ModelConfig::OrHash, String)
+            execution_model:
+              T.any(
+                Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::OrHash,
+                Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject::OrHash,
+                String
+              )
           ).void
         end
         attr_writer :execution_model
@@ -156,11 +171,28 @@ module Stagehand
         attr_writer :mode
 
         # Model configuration object or model name string (e.g., 'openai/gpt-5-nano')
-        sig { returns(T.nilable(T.any(Stagehand::ModelConfig, String))) }
+        sig do
+          returns(
+            T.nilable(
+              T.any(
+                Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject,
+                Stagehand::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject,
+                String
+              )
+            )
+          )
+        end
         attr_reader :model
 
         sig do
-          params(model: T.any(Stagehand::ModelConfig::OrHash, String)).void
+          params(
+            model:
+              T.any(
+                Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::OrHash,
+                Stagehand::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject::OrHash,
+                String
+              )
+          ).void
         end
         attr_writer :model
 
@@ -192,9 +224,19 @@ module Stagehand
         sig do
           params(
             cua: T::Boolean,
-            execution_model: T.any(Stagehand::ModelConfig::OrHash, String),
+            execution_model:
+              T.any(
+                Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::OrHash,
+                Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject::OrHash,
+                String
+              ),
             mode: Stagehand::SessionExecuteParams::AgentConfig::Mode::OrSymbol,
-            model: T.any(Stagehand::ModelConfig::OrHash, String),
+            model:
+              T.any(
+                Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::OrHash,
+                Stagehand::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject::OrHash,
+                String
+              ),
             provider:
               Stagehand::SessionExecuteParams::AgentConfig::Provider::OrSymbol,
             system_prompt: String
@@ -223,10 +265,20 @@ module Stagehand
           override.returns(
             {
               cua: T::Boolean,
-              execution_model: T.any(Stagehand::ModelConfig, String),
+              execution_model:
+                T.any(
+                  Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject,
+                  Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject,
+                  String
+                ),
               mode:
                 Stagehand::SessionExecuteParams::AgentConfig::Mode::OrSymbol,
-              model: T.any(Stagehand::ModelConfig, String),
+              model:
+                T.any(
+                  Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject,
+                  Stagehand::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject,
+                  String
+                ),
               provider:
                 Stagehand::SessionExecuteParams::AgentConfig::Provider::OrSymbol,
               system_prompt: String
@@ -242,7 +294,682 @@ module Stagehand
         module ExecutionModel
           extend Stagehand::Internal::Type::Union
 
-          Variants = T.type_alias { T.any(Stagehand::ModelConfig, String) }
+          Variants =
+            T.type_alias do
+              T.any(
+                Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject,
+                Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject,
+                String
+              )
+            end
+
+          class VertexModelConfigObject < Stagehand::Internal::Type::BaseModel
+            OrHash =
+              T.type_alias do
+                T.any(
+                  Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject,
+                  Stagehand::Internal::AnyHash
+                )
+              end
+
+            # Vertex provider authentication configuration
+            sig do
+              returns(
+                Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth
+              )
+            end
+            attr_reader :auth
+
+            sig do
+              params(
+                auth:
+                  Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::OrHash
+              ).void
+            end
+            attr_writer :auth
+
+            # Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            sig { returns(String) }
+            attr_accessor :model_name
+
+            # Vertex AI model provider
+            sig { returns(Symbol) }
+            attr_accessor :provider
+
+            # Vertex provider-specific model configuration
+            sig do
+              returns(
+                Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::ProviderOptions
+              )
+            end
+            attr_reader :provider_options
+
+            sig do
+              params(
+                provider_options:
+                  Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::ProviderOptions::OrHash
+              ).void
+            end
+            attr_writer :provider_options
+
+            # API key for the model provider
+            sig { returns(T.nilable(String)) }
+            attr_reader :api_key
+
+            sig { params(api_key: String).void }
+            attr_writer :api_key
+
+            # Base URL for the model provider
+            sig { returns(T.nilable(String)) }
+            attr_reader :base_url
+
+            sig { params(base_url: String).void }
+            attr_writer :base_url
+
+            # Custom headers sent with every request to the model provider
+            sig { returns(T.nilable(T::Hash[Symbol, String])) }
+            attr_reader :headers
+
+            sig { params(headers: T::Hash[Symbol, String]).void }
+            attr_writer :headers
+
+            sig do
+              params(
+                auth:
+                  Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::OrHash,
+                model_name: String,
+                provider_options:
+                  Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::ProviderOptions::OrHash,
+                api_key: String,
+                base_url: String,
+                headers: T::Hash[Symbol, String],
+                provider: Symbol
+              ).returns(T.attached_class)
+            end
+            def self.new(
+              # Vertex provider authentication configuration
+              auth:,
+              # Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+              model_name:,
+              # Vertex provider-specific model configuration
+              provider_options:,
+              # API key for the model provider
+              api_key: nil,
+              # Base URL for the model provider
+              base_url: nil,
+              # Custom headers sent with every request to the model provider
+              headers: nil,
+              # Vertex AI model provider
+              provider: :vertex
+            )
+            end
+
+            sig do
+              override.returns(
+                {
+                  auth:
+                    Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth,
+                  model_name: String,
+                  provider: Symbol,
+                  provider_options:
+                    Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::ProviderOptions,
+                  api_key: String,
+                  base_url: String,
+                  headers: T::Hash[Symbol, String]
+                }
+              )
+            end
+            def to_hash
+            end
+
+            class Auth < Stagehand::Internal::Type::BaseModel
+              OrHash =
+                T.type_alias do
+                  T.any(
+                    Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth,
+                    Stagehand::Internal::AnyHash
+                  )
+                end
+
+              # Google Cloud service account credentials
+              sig do
+                returns(
+                  Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials
+                )
+              end
+              attr_reader :credentials
+
+              sig do
+                params(
+                  credentials:
+                    Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials::OrHash
+                ).void
+              end
+              attr_writer :credentials
+
+              # Use inline Google Cloud service account credentials for provider authentication
+              sig { returns(Symbol) }
+              attr_accessor :type
+
+              # Google Cloud project ID used by google-auth-library
+              sig { returns(T.nilable(String)) }
+              attr_reader :project_id
+
+              sig { params(project_id: String).void }
+              attr_writer :project_id
+
+              # Google auth scopes for the desired API request
+              sig do
+                returns(
+                  T.nilable(
+                    Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Scopes::Variants
+                  )
+                )
+              end
+              attr_reader :scopes
+
+              sig do
+                params(
+                  scopes:
+                    Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Scopes::Variants
+                ).void
+              end
+              attr_writer :scopes
+
+              # Google Cloud universe domain
+              sig { returns(T.nilable(String)) }
+              attr_reader :universe_domain
+
+              sig { params(universe_domain: String).void }
+              attr_writer :universe_domain
+
+              # Vertex provider authentication configuration
+              sig do
+                params(
+                  credentials:
+                    Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials::OrHash,
+                  project_id: String,
+                  scopes:
+                    Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Scopes::Variants,
+                  universe_domain: String,
+                  type: Symbol
+                ).returns(T.attached_class)
+              end
+              def self.new(
+                # Google Cloud service account credentials
+                credentials:,
+                # Google Cloud project ID used by google-auth-library
+                project_id: nil,
+                # Google auth scopes for the desired API request
+                scopes: nil,
+                # Google Cloud universe domain
+                universe_domain: nil,
+                # Use inline Google Cloud service account credentials for provider authentication
+                type: :googleServiceAccount
+              )
+              end
+
+              sig do
+                override.returns(
+                  {
+                    credentials:
+                      Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials,
+                    type: Symbol,
+                    project_id: String,
+                    scopes:
+                      Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Scopes::Variants,
+                    universe_domain: String
+                  }
+                )
+              end
+              def to_hash
+              end
+
+              class Credentials < Stagehand::Internal::Type::BaseModel
+                OrHash =
+                  T.type_alias do
+                    T.any(
+                      Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials,
+                      Stagehand::Internal::AnyHash
+                    )
+                  end
+
+                sig { returns(String) }
+                attr_accessor :client_email
+
+                sig { returns(String) }
+                attr_accessor :private_key
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :auth_provider_x509_cert_url
+
+                sig { params(auth_provider_x509_cert_url: String).void }
+                attr_writer :auth_provider_x509_cert_url
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :auth_uri
+
+                sig { params(auth_uri: String).void }
+                attr_writer :auth_uri
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :client_id
+
+                sig { params(client_id: String).void }
+                attr_writer :client_id
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :client_x509_cert_url
+
+                sig { params(client_x509_cert_url: String).void }
+                attr_writer :client_x509_cert_url
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :private_key_id
+
+                sig { params(private_key_id: String).void }
+                attr_writer :private_key_id
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :project_id
+
+                sig { params(project_id: String).void }
+                attr_writer :project_id
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :token_uri
+
+                sig { params(token_uri: String).void }
+                attr_writer :token_uri
+
+                sig do
+                  returns(
+                    T.nilable(
+                      Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials::Type::OrSymbol
+                    )
+                  )
+                end
+                attr_reader :type
+
+                sig do
+                  params(
+                    type:
+                      Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials::Type::OrSymbol
+                  ).void
+                end
+                attr_writer :type
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :universe_domain
+
+                sig { params(universe_domain: String).void }
+                attr_writer :universe_domain
+
+                # Google Cloud service account credentials
+                sig do
+                  params(
+                    client_email: String,
+                    private_key: String,
+                    auth_provider_x509_cert_url: String,
+                    auth_uri: String,
+                    client_id: String,
+                    client_x509_cert_url: String,
+                    private_key_id: String,
+                    project_id: String,
+                    token_uri: String,
+                    type:
+                      Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials::Type::OrSymbol,
+                    universe_domain: String
+                  ).returns(T.attached_class)
+                end
+                def self.new(
+                  client_email:,
+                  private_key:,
+                  auth_provider_x509_cert_url: nil,
+                  auth_uri: nil,
+                  client_id: nil,
+                  client_x509_cert_url: nil,
+                  private_key_id: nil,
+                  project_id: nil,
+                  token_uri: nil,
+                  type: nil,
+                  universe_domain: nil
+                )
+                end
+
+                sig do
+                  override.returns(
+                    {
+                      client_email: String,
+                      private_key: String,
+                      auth_provider_x509_cert_url: String,
+                      auth_uri: String,
+                      client_id: String,
+                      client_x509_cert_url: String,
+                      private_key_id: String,
+                      project_id: String,
+                      token_uri: String,
+                      type:
+                        Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials::Type::OrSymbol,
+                      universe_domain: String
+                    }
+                  )
+                end
+                def to_hash
+                end
+
+                module Type
+                  extend Stagehand::Internal::Type::Enum
+
+                  TaggedSymbol =
+                    T.type_alias do
+                      T.all(
+                        Symbol,
+                        Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials::Type
+                      )
+                    end
+                  OrSymbol = T.type_alias { T.any(Symbol, String) }
+
+                  SERVICE_ACCOUNT =
+                    T.let(
+                      :service_account,
+                      Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials::Type::TaggedSymbol
+                    )
+
+                  sig do
+                    override.returns(
+                      T::Array[
+                        Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials::Type::TaggedSymbol
+                      ]
+                    )
+                  end
+                  def self.values
+                  end
+                end
+              end
+
+              # Google auth scopes for the desired API request
+              module Scopes
+                extend Stagehand::Internal::Type::Union
+
+                Variants = T.type_alias { T.any(String, T::Array[String]) }
+
+                sig do
+                  override.returns(
+                    T::Array[
+                      Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Scopes::Variants
+                    ]
+                  )
+                end
+                def self.variants
+                end
+
+                StringArray =
+                  T.let(
+                    Stagehand::Internal::Type::ArrayOf[String],
+                    Stagehand::Internal::Type::Converter
+                  )
+              end
+            end
+
+            class ProviderOptions < Stagehand::Internal::Type::BaseModel
+              OrHash =
+                T.type_alias do
+                  T.any(
+                    Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::ProviderOptions,
+                    Stagehand::Internal::AnyHash
+                  )
+                end
+
+              # Vertex AI provider-specific settings
+              sig do
+                returns(
+                  Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::ProviderOptions::Vertex
+                )
+              end
+              attr_reader :vertex
+
+              sig do
+                params(
+                  vertex:
+                    Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::ProviderOptions::Vertex::OrHash
+                ).void
+              end
+              attr_writer :vertex
+
+              # Vertex provider-specific model configuration
+              sig do
+                params(
+                  vertex:
+                    Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::ProviderOptions::Vertex::OrHash
+                ).returns(T.attached_class)
+              end
+              def self.new(
+                # Vertex AI provider-specific settings
+                vertex:
+              )
+              end
+
+              sig do
+                override.returns(
+                  {
+                    vertex:
+                      Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::ProviderOptions::Vertex
+                  }
+                )
+              end
+              def to_hash
+              end
+
+              class Vertex < Stagehand::Internal::Type::BaseModel
+                OrHash =
+                  T.type_alias do
+                    T.any(
+                      Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::ProviderOptions::Vertex,
+                      Stagehand::Internal::AnyHash
+                    )
+                  end
+
+                # Google Cloud location for Vertex AI models
+                sig { returns(String) }
+                attr_accessor :location
+
+                # Google Cloud project ID for Vertex AI models
+                sig { returns(String) }
+                attr_accessor :project
+
+                # Base URL for the Vertex AI provider
+                sig { returns(T.nilable(String)) }
+                attr_reader :base_url
+
+                sig { params(base_url: String).void }
+                attr_writer :base_url
+
+                # Custom headers sent with every request to the Vertex AI provider
+                sig { returns(T.nilable(T::Hash[Symbol, String])) }
+                attr_reader :headers
+
+                sig { params(headers: T::Hash[Symbol, String]).void }
+                attr_writer :headers
+
+                # Vertex AI provider-specific settings
+                sig do
+                  params(
+                    location: String,
+                    project: String,
+                    base_url: String,
+                    headers: T::Hash[Symbol, String]
+                  ).returns(T.attached_class)
+                end
+                def self.new(
+                  # Google Cloud location for Vertex AI models
+                  location:,
+                  # Google Cloud project ID for Vertex AI models
+                  project:,
+                  # Base URL for the Vertex AI provider
+                  base_url: nil,
+                  # Custom headers sent with every request to the Vertex AI provider
+                  headers: nil
+                )
+                end
+
+                sig do
+                  override.returns(
+                    {
+                      location: String,
+                      project: String,
+                      base_url: String,
+                      headers: T::Hash[Symbol, String]
+                    }
+                  )
+                end
+                def to_hash
+                end
+              end
+            end
+          end
+
+          class GenericModelConfigObject < Stagehand::Internal::Type::BaseModel
+            OrHash =
+              T.type_alias do
+                T.any(
+                  Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject,
+                  Stagehand::Internal::AnyHash
+                )
+              end
+
+            # Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            sig { returns(String) }
+            attr_accessor :model_name
+
+            # API key for the model provider
+            sig { returns(T.nilable(String)) }
+            attr_reader :api_key
+
+            sig { params(api_key: String).void }
+            attr_writer :api_key
+
+            # Base URL for the model provider
+            sig { returns(T.nilable(String)) }
+            attr_reader :base_url
+
+            sig { params(base_url: String).void }
+            attr_writer :base_url
+
+            # Custom headers sent with every request to the model provider
+            sig { returns(T.nilable(T::Hash[Symbol, String])) }
+            attr_reader :headers
+
+            sig { params(headers: T::Hash[Symbol, String]).void }
+            attr_writer :headers
+
+            # AI provider for the model (or provide a baseURL endpoint instead)
+            sig do
+              returns(
+                T.nilable(
+                  Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject::Provider::OrSymbol
+                )
+              )
+            end
+            attr_reader :provider
+
+            sig do
+              params(
+                provider:
+                  Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject::Provider::OrSymbol
+              ).void
+            end
+            attr_writer :provider
+
+            sig do
+              params(
+                model_name: String,
+                api_key: String,
+                base_url: String,
+                headers: T::Hash[Symbol, String],
+                provider:
+                  Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject::Provider::OrSymbol
+              ).returns(T.attached_class)
+            end
+            def self.new(
+              # Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+              model_name:,
+              # API key for the model provider
+              api_key: nil,
+              # Base URL for the model provider
+              base_url: nil,
+              # Custom headers sent with every request to the model provider
+              headers: nil,
+              # AI provider for the model (or provide a baseURL endpoint instead)
+              provider: nil
+            )
+            end
+
+            sig do
+              override.returns(
+                {
+                  model_name: String,
+                  api_key: String,
+                  base_url: String,
+                  headers: T::Hash[Symbol, String],
+                  provider:
+                    Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject::Provider::OrSymbol
+                }
+              )
+            end
+            def to_hash
+            end
+
+            # AI provider for the model (or provide a baseURL endpoint instead)
+            module Provider
+              extend Stagehand::Internal::Type::Enum
+
+              TaggedSymbol =
+                T.type_alias do
+                  T.all(
+                    Symbol,
+                    Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject::Provider
+                  )
+                end
+              OrSymbol = T.type_alias { T.any(Symbol, String) }
+
+              OPENAI =
+                T.let(
+                  :openai,
+                  Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject::Provider::TaggedSymbol
+                )
+              ANTHROPIC =
+                T.let(
+                  :anthropic,
+                  Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject::Provider::TaggedSymbol
+                )
+              GOOGLE =
+                T.let(
+                  :google,
+                  Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject::Provider::TaggedSymbol
+                )
+              MICROSOFT =
+                T.let(
+                  :microsoft,
+                  Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject::Provider::TaggedSymbol
+                )
+              BEDROCK =
+                T.let(
+                  :bedrock,
+                  Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject::Provider::TaggedSymbol
+                )
+
+              sig do
+                override.returns(
+                  T::Array[
+                    Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject::Provider::TaggedSymbol
+                  ]
+                )
+              end
+              def self.values
+              end
+            end
+          end
 
           sig do
             override.returns(
@@ -296,7 +1023,682 @@ module Stagehand
         module Model
           extend Stagehand::Internal::Type::Union
 
-          Variants = T.type_alias { T.any(Stagehand::ModelConfig, String) }
+          Variants =
+            T.type_alias do
+              T.any(
+                Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject,
+                Stagehand::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject,
+                String
+              )
+            end
+
+          class VertexModelConfigObject < Stagehand::Internal::Type::BaseModel
+            OrHash =
+              T.type_alias do
+                T.any(
+                  Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject,
+                  Stagehand::Internal::AnyHash
+                )
+              end
+
+            # Vertex provider authentication configuration
+            sig do
+              returns(
+                Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth
+              )
+            end
+            attr_reader :auth
+
+            sig do
+              params(
+                auth:
+                  Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::OrHash
+              ).void
+            end
+            attr_writer :auth
+
+            # Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            sig { returns(String) }
+            attr_accessor :model_name
+
+            # Vertex AI model provider
+            sig { returns(Symbol) }
+            attr_accessor :provider
+
+            # Vertex provider-specific model configuration
+            sig do
+              returns(
+                Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::ProviderOptions
+              )
+            end
+            attr_reader :provider_options
+
+            sig do
+              params(
+                provider_options:
+                  Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::ProviderOptions::OrHash
+              ).void
+            end
+            attr_writer :provider_options
+
+            # API key for the model provider
+            sig { returns(T.nilable(String)) }
+            attr_reader :api_key
+
+            sig { params(api_key: String).void }
+            attr_writer :api_key
+
+            # Base URL for the model provider
+            sig { returns(T.nilable(String)) }
+            attr_reader :base_url
+
+            sig { params(base_url: String).void }
+            attr_writer :base_url
+
+            # Custom headers sent with every request to the model provider
+            sig { returns(T.nilable(T::Hash[Symbol, String])) }
+            attr_reader :headers
+
+            sig { params(headers: T::Hash[Symbol, String]).void }
+            attr_writer :headers
+
+            sig do
+              params(
+                auth:
+                  Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::OrHash,
+                model_name: String,
+                provider_options:
+                  Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::ProviderOptions::OrHash,
+                api_key: String,
+                base_url: String,
+                headers: T::Hash[Symbol, String],
+                provider: Symbol
+              ).returns(T.attached_class)
+            end
+            def self.new(
+              # Vertex provider authentication configuration
+              auth:,
+              # Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+              model_name:,
+              # Vertex provider-specific model configuration
+              provider_options:,
+              # API key for the model provider
+              api_key: nil,
+              # Base URL for the model provider
+              base_url: nil,
+              # Custom headers sent with every request to the model provider
+              headers: nil,
+              # Vertex AI model provider
+              provider: :vertex
+            )
+            end
+
+            sig do
+              override.returns(
+                {
+                  auth:
+                    Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth,
+                  model_name: String,
+                  provider: Symbol,
+                  provider_options:
+                    Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::ProviderOptions,
+                  api_key: String,
+                  base_url: String,
+                  headers: T::Hash[Symbol, String]
+                }
+              )
+            end
+            def to_hash
+            end
+
+            class Auth < Stagehand::Internal::Type::BaseModel
+              OrHash =
+                T.type_alias do
+                  T.any(
+                    Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth,
+                    Stagehand::Internal::AnyHash
+                  )
+                end
+
+              # Google Cloud service account credentials
+              sig do
+                returns(
+                  Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials
+                )
+              end
+              attr_reader :credentials
+
+              sig do
+                params(
+                  credentials:
+                    Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials::OrHash
+                ).void
+              end
+              attr_writer :credentials
+
+              # Use inline Google Cloud service account credentials for provider authentication
+              sig { returns(Symbol) }
+              attr_accessor :type
+
+              # Google Cloud project ID used by google-auth-library
+              sig { returns(T.nilable(String)) }
+              attr_reader :project_id
+
+              sig { params(project_id: String).void }
+              attr_writer :project_id
+
+              # Google auth scopes for the desired API request
+              sig do
+                returns(
+                  T.nilable(
+                    Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Scopes::Variants
+                  )
+                )
+              end
+              attr_reader :scopes
+
+              sig do
+                params(
+                  scopes:
+                    Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Scopes::Variants
+                ).void
+              end
+              attr_writer :scopes
+
+              # Google Cloud universe domain
+              sig { returns(T.nilable(String)) }
+              attr_reader :universe_domain
+
+              sig { params(universe_domain: String).void }
+              attr_writer :universe_domain
+
+              # Vertex provider authentication configuration
+              sig do
+                params(
+                  credentials:
+                    Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials::OrHash,
+                  project_id: String,
+                  scopes:
+                    Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Scopes::Variants,
+                  universe_domain: String,
+                  type: Symbol
+                ).returns(T.attached_class)
+              end
+              def self.new(
+                # Google Cloud service account credentials
+                credentials:,
+                # Google Cloud project ID used by google-auth-library
+                project_id: nil,
+                # Google auth scopes for the desired API request
+                scopes: nil,
+                # Google Cloud universe domain
+                universe_domain: nil,
+                # Use inline Google Cloud service account credentials for provider authentication
+                type: :googleServiceAccount
+              )
+              end
+
+              sig do
+                override.returns(
+                  {
+                    credentials:
+                      Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials,
+                    type: Symbol,
+                    project_id: String,
+                    scopes:
+                      Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Scopes::Variants,
+                    universe_domain: String
+                  }
+                )
+              end
+              def to_hash
+              end
+
+              class Credentials < Stagehand::Internal::Type::BaseModel
+                OrHash =
+                  T.type_alias do
+                    T.any(
+                      Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials,
+                      Stagehand::Internal::AnyHash
+                    )
+                  end
+
+                sig { returns(String) }
+                attr_accessor :client_email
+
+                sig { returns(String) }
+                attr_accessor :private_key
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :auth_provider_x509_cert_url
+
+                sig { params(auth_provider_x509_cert_url: String).void }
+                attr_writer :auth_provider_x509_cert_url
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :auth_uri
+
+                sig { params(auth_uri: String).void }
+                attr_writer :auth_uri
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :client_id
+
+                sig { params(client_id: String).void }
+                attr_writer :client_id
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :client_x509_cert_url
+
+                sig { params(client_x509_cert_url: String).void }
+                attr_writer :client_x509_cert_url
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :private_key_id
+
+                sig { params(private_key_id: String).void }
+                attr_writer :private_key_id
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :project_id
+
+                sig { params(project_id: String).void }
+                attr_writer :project_id
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :token_uri
+
+                sig { params(token_uri: String).void }
+                attr_writer :token_uri
+
+                sig do
+                  returns(
+                    T.nilable(
+                      Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials::Type::OrSymbol
+                    )
+                  )
+                end
+                attr_reader :type
+
+                sig do
+                  params(
+                    type:
+                      Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials::Type::OrSymbol
+                  ).void
+                end
+                attr_writer :type
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :universe_domain
+
+                sig { params(universe_domain: String).void }
+                attr_writer :universe_domain
+
+                # Google Cloud service account credentials
+                sig do
+                  params(
+                    client_email: String,
+                    private_key: String,
+                    auth_provider_x509_cert_url: String,
+                    auth_uri: String,
+                    client_id: String,
+                    client_x509_cert_url: String,
+                    private_key_id: String,
+                    project_id: String,
+                    token_uri: String,
+                    type:
+                      Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials::Type::OrSymbol,
+                    universe_domain: String
+                  ).returns(T.attached_class)
+                end
+                def self.new(
+                  client_email:,
+                  private_key:,
+                  auth_provider_x509_cert_url: nil,
+                  auth_uri: nil,
+                  client_id: nil,
+                  client_x509_cert_url: nil,
+                  private_key_id: nil,
+                  project_id: nil,
+                  token_uri: nil,
+                  type: nil,
+                  universe_domain: nil
+                )
+                end
+
+                sig do
+                  override.returns(
+                    {
+                      client_email: String,
+                      private_key: String,
+                      auth_provider_x509_cert_url: String,
+                      auth_uri: String,
+                      client_id: String,
+                      client_x509_cert_url: String,
+                      private_key_id: String,
+                      project_id: String,
+                      token_uri: String,
+                      type:
+                        Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials::Type::OrSymbol,
+                      universe_domain: String
+                    }
+                  )
+                end
+                def to_hash
+                end
+
+                module Type
+                  extend Stagehand::Internal::Type::Enum
+
+                  TaggedSymbol =
+                    T.type_alias do
+                      T.all(
+                        Symbol,
+                        Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials::Type
+                      )
+                    end
+                  OrSymbol = T.type_alias { T.any(Symbol, String) }
+
+                  SERVICE_ACCOUNT =
+                    T.let(
+                      :service_account,
+                      Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials::Type::TaggedSymbol
+                    )
+
+                  sig do
+                    override.returns(
+                      T::Array[
+                        Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials::Type::TaggedSymbol
+                      ]
+                    )
+                  end
+                  def self.values
+                  end
+                end
+              end
+
+              # Google auth scopes for the desired API request
+              module Scopes
+                extend Stagehand::Internal::Type::Union
+
+                Variants = T.type_alias { T.any(String, T::Array[String]) }
+
+                sig do
+                  override.returns(
+                    T::Array[
+                      Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Scopes::Variants
+                    ]
+                  )
+                end
+                def self.variants
+                end
+
+                StringArray =
+                  T.let(
+                    Stagehand::Internal::Type::ArrayOf[String],
+                    Stagehand::Internal::Type::Converter
+                  )
+              end
+            end
+
+            class ProviderOptions < Stagehand::Internal::Type::BaseModel
+              OrHash =
+                T.type_alias do
+                  T.any(
+                    Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::ProviderOptions,
+                    Stagehand::Internal::AnyHash
+                  )
+                end
+
+              # Vertex AI provider-specific settings
+              sig do
+                returns(
+                  Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::ProviderOptions::Vertex
+                )
+              end
+              attr_reader :vertex
+
+              sig do
+                params(
+                  vertex:
+                    Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::ProviderOptions::Vertex::OrHash
+                ).void
+              end
+              attr_writer :vertex
+
+              # Vertex provider-specific model configuration
+              sig do
+                params(
+                  vertex:
+                    Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::ProviderOptions::Vertex::OrHash
+                ).returns(T.attached_class)
+              end
+              def self.new(
+                # Vertex AI provider-specific settings
+                vertex:
+              )
+              end
+
+              sig do
+                override.returns(
+                  {
+                    vertex:
+                      Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::ProviderOptions::Vertex
+                  }
+                )
+              end
+              def to_hash
+              end
+
+              class Vertex < Stagehand::Internal::Type::BaseModel
+                OrHash =
+                  T.type_alias do
+                    T.any(
+                      Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::ProviderOptions::Vertex,
+                      Stagehand::Internal::AnyHash
+                    )
+                  end
+
+                # Google Cloud location for Vertex AI models
+                sig { returns(String) }
+                attr_accessor :location
+
+                # Google Cloud project ID for Vertex AI models
+                sig { returns(String) }
+                attr_accessor :project
+
+                # Base URL for the Vertex AI provider
+                sig { returns(T.nilable(String)) }
+                attr_reader :base_url
+
+                sig { params(base_url: String).void }
+                attr_writer :base_url
+
+                # Custom headers sent with every request to the Vertex AI provider
+                sig { returns(T.nilable(T::Hash[Symbol, String])) }
+                attr_reader :headers
+
+                sig { params(headers: T::Hash[Symbol, String]).void }
+                attr_writer :headers
+
+                # Vertex AI provider-specific settings
+                sig do
+                  params(
+                    location: String,
+                    project: String,
+                    base_url: String,
+                    headers: T::Hash[Symbol, String]
+                  ).returns(T.attached_class)
+                end
+                def self.new(
+                  # Google Cloud location for Vertex AI models
+                  location:,
+                  # Google Cloud project ID for Vertex AI models
+                  project:,
+                  # Base URL for the Vertex AI provider
+                  base_url: nil,
+                  # Custom headers sent with every request to the Vertex AI provider
+                  headers: nil
+                )
+                end
+
+                sig do
+                  override.returns(
+                    {
+                      location: String,
+                      project: String,
+                      base_url: String,
+                      headers: T::Hash[Symbol, String]
+                    }
+                  )
+                end
+                def to_hash
+                end
+              end
+            end
+          end
+
+          class GenericModelConfigObject < Stagehand::Internal::Type::BaseModel
+            OrHash =
+              T.type_alias do
+                T.any(
+                  Stagehand::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject,
+                  Stagehand::Internal::AnyHash
+                )
+              end
+
+            # Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            sig { returns(String) }
+            attr_accessor :model_name
+
+            # API key for the model provider
+            sig { returns(T.nilable(String)) }
+            attr_reader :api_key
+
+            sig { params(api_key: String).void }
+            attr_writer :api_key
+
+            # Base URL for the model provider
+            sig { returns(T.nilable(String)) }
+            attr_reader :base_url
+
+            sig { params(base_url: String).void }
+            attr_writer :base_url
+
+            # Custom headers sent with every request to the model provider
+            sig { returns(T.nilable(T::Hash[Symbol, String])) }
+            attr_reader :headers
+
+            sig { params(headers: T::Hash[Symbol, String]).void }
+            attr_writer :headers
+
+            # AI provider for the model (or provide a baseURL endpoint instead)
+            sig do
+              returns(
+                T.nilable(
+                  Stagehand::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject::Provider::OrSymbol
+                )
+              )
+            end
+            attr_reader :provider
+
+            sig do
+              params(
+                provider:
+                  Stagehand::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject::Provider::OrSymbol
+              ).void
+            end
+            attr_writer :provider
+
+            sig do
+              params(
+                model_name: String,
+                api_key: String,
+                base_url: String,
+                headers: T::Hash[Symbol, String],
+                provider:
+                  Stagehand::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject::Provider::OrSymbol
+              ).returns(T.attached_class)
+            end
+            def self.new(
+              # Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+              model_name:,
+              # API key for the model provider
+              api_key: nil,
+              # Base URL for the model provider
+              base_url: nil,
+              # Custom headers sent with every request to the model provider
+              headers: nil,
+              # AI provider for the model (or provide a baseURL endpoint instead)
+              provider: nil
+            )
+            end
+
+            sig do
+              override.returns(
+                {
+                  model_name: String,
+                  api_key: String,
+                  base_url: String,
+                  headers: T::Hash[Symbol, String],
+                  provider:
+                    Stagehand::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject::Provider::OrSymbol
+                }
+              )
+            end
+            def to_hash
+            end
+
+            # AI provider for the model (or provide a baseURL endpoint instead)
+            module Provider
+              extend Stagehand::Internal::Type::Enum
+
+              TaggedSymbol =
+                T.type_alias do
+                  T.all(
+                    Symbol,
+                    Stagehand::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject::Provider
+                  )
+                end
+              OrSymbol = T.type_alias { T.any(Symbol, String) }
+
+              OPENAI =
+                T.let(
+                  :openai,
+                  Stagehand::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject::Provider::TaggedSymbol
+                )
+              ANTHROPIC =
+                T.let(
+                  :anthropic,
+                  Stagehand::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject::Provider::TaggedSymbol
+                )
+              GOOGLE =
+                T.let(
+                  :google,
+                  Stagehand::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject::Provider::TaggedSymbol
+                )
+              MICROSOFT =
+                T.let(
+                  :microsoft,
+                  Stagehand::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject::Provider::TaggedSymbol
+                )
+              BEDROCK =
+                T.let(
+                  :bedrock,
+                  Stagehand::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject::Provider::TaggedSymbol
+                )
+
+              sig do
+                override.returns(
+                  T::Array[
+                    Stagehand::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject::Provider::TaggedSymbol
+                  ]
+                )
+              end
+              def self.values
+              end
+            end
+          end
 
           sig do
             override.returns(
diff --git a/rbi/stagehand/models/session_extract_params.rbi b/rbi/stagehand/models/session_extract_params.rbi
index 2fc2eb4..970dce0 100644
--- a/rbi/stagehand/models/session_extract_params.rbi
+++ b/rbi/stagehand/models/session_extract_params.rbi
@@ -119,14 +119,39 @@ module Stagehand
         attr_writer :ignore_selectors
 
         # Model configuration object or model name string (e.g., 'openai/gpt-5-nano')
-        sig { returns(T.nilable(T.any(Stagehand::ModelConfig, String))) }
+        sig do
+          returns(
+            T.nilable(
+              T.any(
+                Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject,
+                Stagehand::SessionExtractParams::Options::Model::GenericModelConfigObject,
+                String
+              )
+            )
+          )
+        end
         attr_reader :model
 
         sig do
-          params(model: T.any(Stagehand::ModelConfig::OrHash, String)).void
+          params(
+            model:
+              T.any(
+                Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::OrHash,
+                Stagehand::SessionExtractParams::Options::Model::GenericModelConfigObject::OrHash,
+                String
+              )
+          ).void
         end
         attr_writer :model
 
+        # When true, include a screenshot of the current viewport in the extraction LLM
+        # call. Defaults to false.
+        sig { returns(T.nilable(T::Boolean)) }
+        attr_reader :screenshot
+
+        sig { params(screenshot: T::Boolean).void }
+        attr_writer :screenshot
+
         # CSS selector to scope extraction to a specific element
         sig { returns(T.nilable(String)) }
         attr_reader :selector
@@ -144,7 +169,13 @@ module Stagehand
         sig do
           params(
             ignore_selectors: T::Array[String],
-            model: T.any(Stagehand::ModelConfig::OrHash, String),
+            model:
+              T.any(
+                Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::OrHash,
+                Stagehand::SessionExtractParams::Options::Model::GenericModelConfigObject::OrHash,
+                String
+              ),
+            screenshot: T::Boolean,
             selector: String,
             timeout: Float
           ).returns(T.attached_class)
@@ -154,6 +185,9 @@ module Stagehand
           ignore_selectors: nil,
           # Model configuration object or model name string (e.g., 'openai/gpt-5-nano')
           model: nil,
+          # When true, include a screenshot of the current viewport in the extraction LLM
+          # call. Defaults to false.
+          screenshot: nil,
           # CSS selector to scope extraction to a specific element
           selector: nil,
           # Timeout in ms for the extraction
@@ -165,7 +199,13 @@ module Stagehand
           override.returns(
             {
               ignore_selectors: T::Array[String],
-              model: T.any(Stagehand::ModelConfig, String),
+              model:
+                T.any(
+                  Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject,
+                  Stagehand::SessionExtractParams::Options::Model::GenericModelConfigObject,
+                  String
+                ),
+              screenshot: T::Boolean,
               selector: String,
               timeout: Float
             }
@@ -178,7 +218,682 @@ module Stagehand
         module Model
           extend Stagehand::Internal::Type::Union
 
-          Variants = T.type_alias { T.any(Stagehand::ModelConfig, String) }
+          Variants =
+            T.type_alias do
+              T.any(
+                Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject,
+                Stagehand::SessionExtractParams::Options::Model::GenericModelConfigObject,
+                String
+              )
+            end
+
+          class VertexModelConfigObject < Stagehand::Internal::Type::BaseModel
+            OrHash =
+              T.type_alias do
+                T.any(
+                  Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject,
+                  Stagehand::Internal::AnyHash
+                )
+              end
+
+            # Vertex provider authentication configuration
+            sig do
+              returns(
+                Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth
+              )
+            end
+            attr_reader :auth
+
+            sig do
+              params(
+                auth:
+                  Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::OrHash
+              ).void
+            end
+            attr_writer :auth
+
+            # Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            sig { returns(String) }
+            attr_accessor :model_name
+
+            # Vertex AI model provider
+            sig { returns(Symbol) }
+            attr_accessor :provider
+
+            # Vertex provider-specific model configuration
+            sig do
+              returns(
+                Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::ProviderOptions
+              )
+            end
+            attr_reader :provider_options
+
+            sig do
+              params(
+                provider_options:
+                  Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::ProviderOptions::OrHash
+              ).void
+            end
+            attr_writer :provider_options
+
+            # API key for the model provider
+            sig { returns(T.nilable(String)) }
+            attr_reader :api_key
+
+            sig { params(api_key: String).void }
+            attr_writer :api_key
+
+            # Base URL for the model provider
+            sig { returns(T.nilable(String)) }
+            attr_reader :base_url
+
+            sig { params(base_url: String).void }
+            attr_writer :base_url
+
+            # Custom headers sent with every request to the model provider
+            sig { returns(T.nilable(T::Hash[Symbol, String])) }
+            attr_reader :headers
+
+            sig { params(headers: T::Hash[Symbol, String]).void }
+            attr_writer :headers
+
+            sig do
+              params(
+                auth:
+                  Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::OrHash,
+                model_name: String,
+                provider_options:
+                  Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::ProviderOptions::OrHash,
+                api_key: String,
+                base_url: String,
+                headers: T::Hash[Symbol, String],
+                provider: Symbol
+              ).returns(T.attached_class)
+            end
+            def self.new(
+              # Vertex provider authentication configuration
+              auth:,
+              # Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+              model_name:,
+              # Vertex provider-specific model configuration
+              provider_options:,
+              # API key for the model provider
+              api_key: nil,
+              # Base URL for the model provider
+              base_url: nil,
+              # Custom headers sent with every request to the model provider
+              headers: nil,
+              # Vertex AI model provider
+              provider: :vertex
+            )
+            end
+
+            sig do
+              override.returns(
+                {
+                  auth:
+                    Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth,
+                  model_name: String,
+                  provider: Symbol,
+                  provider_options:
+                    Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::ProviderOptions,
+                  api_key: String,
+                  base_url: String,
+                  headers: T::Hash[Symbol, String]
+                }
+              )
+            end
+            def to_hash
+            end
+
+            class Auth < Stagehand::Internal::Type::BaseModel
+              OrHash =
+                T.type_alias do
+                  T.any(
+                    Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth,
+                    Stagehand::Internal::AnyHash
+                  )
+                end
+
+              # Google Cloud service account credentials
+              sig do
+                returns(
+                  Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials
+                )
+              end
+              attr_reader :credentials
+
+              sig do
+                params(
+                  credentials:
+                    Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials::OrHash
+                ).void
+              end
+              attr_writer :credentials
+
+              # Use inline Google Cloud service account credentials for provider authentication
+              sig { returns(Symbol) }
+              attr_accessor :type
+
+              # Google Cloud project ID used by google-auth-library
+              sig { returns(T.nilable(String)) }
+              attr_reader :project_id
+
+              sig { params(project_id: String).void }
+              attr_writer :project_id
+
+              # Google auth scopes for the desired API request
+              sig do
+                returns(
+                  T.nilable(
+                    Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Scopes::Variants
+                  )
+                )
+              end
+              attr_reader :scopes
+
+              sig do
+                params(
+                  scopes:
+                    Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Scopes::Variants
+                ).void
+              end
+              attr_writer :scopes
+
+              # Google Cloud universe domain
+              sig { returns(T.nilable(String)) }
+              attr_reader :universe_domain
+
+              sig { params(universe_domain: String).void }
+              attr_writer :universe_domain
+
+              # Vertex provider authentication configuration
+              sig do
+                params(
+                  credentials:
+                    Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials::OrHash,
+                  project_id: String,
+                  scopes:
+                    Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Scopes::Variants,
+                  universe_domain: String,
+                  type: Symbol
+                ).returns(T.attached_class)
+              end
+              def self.new(
+                # Google Cloud service account credentials
+                credentials:,
+                # Google Cloud project ID used by google-auth-library
+                project_id: nil,
+                # Google auth scopes for the desired API request
+                scopes: nil,
+                # Google Cloud universe domain
+                universe_domain: nil,
+                # Use inline Google Cloud service account credentials for provider authentication
+                type: :googleServiceAccount
+              )
+              end
+
+              sig do
+                override.returns(
+                  {
+                    credentials:
+                      Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials,
+                    type: Symbol,
+                    project_id: String,
+                    scopes:
+                      Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Scopes::Variants,
+                    universe_domain: String
+                  }
+                )
+              end
+              def to_hash
+              end
+
+              class Credentials < Stagehand::Internal::Type::BaseModel
+                OrHash =
+                  T.type_alias do
+                    T.any(
+                      Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials,
+                      Stagehand::Internal::AnyHash
+                    )
+                  end
+
+                sig { returns(String) }
+                attr_accessor :client_email
+
+                sig { returns(String) }
+                attr_accessor :private_key
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :auth_provider_x509_cert_url
+
+                sig { params(auth_provider_x509_cert_url: String).void }
+                attr_writer :auth_provider_x509_cert_url
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :auth_uri
+
+                sig { params(auth_uri: String).void }
+                attr_writer :auth_uri
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :client_id
+
+                sig { params(client_id: String).void }
+                attr_writer :client_id
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :client_x509_cert_url
+
+                sig { params(client_x509_cert_url: String).void }
+                attr_writer :client_x509_cert_url
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :private_key_id
+
+                sig { params(private_key_id: String).void }
+                attr_writer :private_key_id
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :project_id
+
+                sig { params(project_id: String).void }
+                attr_writer :project_id
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :token_uri
+
+                sig { params(token_uri: String).void }
+                attr_writer :token_uri
+
+                sig do
+                  returns(
+                    T.nilable(
+                      Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type::OrSymbol
+                    )
+                  )
+                end
+                attr_reader :type
+
+                sig do
+                  params(
+                    type:
+                      Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type::OrSymbol
+                  ).void
+                end
+                attr_writer :type
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :universe_domain
+
+                sig { params(universe_domain: String).void }
+                attr_writer :universe_domain
+
+                # Google Cloud service account credentials
+                sig do
+                  params(
+                    client_email: String,
+                    private_key: String,
+                    auth_provider_x509_cert_url: String,
+                    auth_uri: String,
+                    client_id: String,
+                    client_x509_cert_url: String,
+                    private_key_id: String,
+                    project_id: String,
+                    token_uri: String,
+                    type:
+                      Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type::OrSymbol,
+                    universe_domain: String
+                  ).returns(T.attached_class)
+                end
+                def self.new(
+                  client_email:,
+                  private_key:,
+                  auth_provider_x509_cert_url: nil,
+                  auth_uri: nil,
+                  client_id: nil,
+                  client_x509_cert_url: nil,
+                  private_key_id: nil,
+                  project_id: nil,
+                  token_uri: nil,
+                  type: nil,
+                  universe_domain: nil
+                )
+                end
+
+                sig do
+                  override.returns(
+                    {
+                      client_email: String,
+                      private_key: String,
+                      auth_provider_x509_cert_url: String,
+                      auth_uri: String,
+                      client_id: String,
+                      client_x509_cert_url: String,
+                      private_key_id: String,
+                      project_id: String,
+                      token_uri: String,
+                      type:
+                        Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type::OrSymbol,
+                      universe_domain: String
+                    }
+                  )
+                end
+                def to_hash
+                end
+
+                module Type
+                  extend Stagehand::Internal::Type::Enum
+
+                  TaggedSymbol =
+                    T.type_alias do
+                      T.all(
+                        Symbol,
+                        Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type
+                      )
+                    end
+                  OrSymbol = T.type_alias { T.any(Symbol, String) }
+
+                  SERVICE_ACCOUNT =
+                    T.let(
+                      :service_account,
+                      Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type::TaggedSymbol
+                    )
+
+                  sig do
+                    override.returns(
+                      T::Array[
+                        Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type::TaggedSymbol
+                      ]
+                    )
+                  end
+                  def self.values
+                  end
+                end
+              end
+
+              # Google auth scopes for the desired API request
+              module Scopes
+                extend Stagehand::Internal::Type::Union
+
+                Variants = T.type_alias { T.any(String, T::Array[String]) }
+
+                sig do
+                  override.returns(
+                    T::Array[
+                      Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Scopes::Variants
+                    ]
+                  )
+                end
+                def self.variants
+                end
+
+                StringArray =
+                  T.let(
+                    Stagehand::Internal::Type::ArrayOf[String],
+                    Stagehand::Internal::Type::Converter
+                  )
+              end
+            end
+
+            class ProviderOptions < Stagehand::Internal::Type::BaseModel
+              OrHash =
+                T.type_alias do
+                  T.any(
+                    Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::ProviderOptions,
+                    Stagehand::Internal::AnyHash
+                  )
+                end
+
+              # Vertex AI provider-specific settings
+              sig do
+                returns(
+                  Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex
+                )
+              end
+              attr_reader :vertex
+
+              sig do
+                params(
+                  vertex:
+                    Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex::OrHash
+                ).void
+              end
+              attr_writer :vertex
+
+              # Vertex provider-specific model configuration
+              sig do
+                params(
+                  vertex:
+                    Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex::OrHash
+                ).returns(T.attached_class)
+              end
+              def self.new(
+                # Vertex AI provider-specific settings
+                vertex:
+              )
+              end
+
+              sig do
+                override.returns(
+                  {
+                    vertex:
+                      Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex
+                  }
+                )
+              end
+              def to_hash
+              end
+
+              class Vertex < Stagehand::Internal::Type::BaseModel
+                OrHash =
+                  T.type_alias do
+                    T.any(
+                      Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex,
+                      Stagehand::Internal::AnyHash
+                    )
+                  end
+
+                # Google Cloud location for Vertex AI models
+                sig { returns(String) }
+                attr_accessor :location
+
+                # Google Cloud project ID for Vertex AI models
+                sig { returns(String) }
+                attr_accessor :project
+
+                # Base URL for the Vertex AI provider
+                sig { returns(T.nilable(String)) }
+                attr_reader :base_url
+
+                sig { params(base_url: String).void }
+                attr_writer :base_url
+
+                # Custom headers sent with every request to the Vertex AI provider
+                sig { returns(T.nilable(T::Hash[Symbol, String])) }
+                attr_reader :headers
+
+                sig { params(headers: T::Hash[Symbol, String]).void }
+                attr_writer :headers
+
+                # Vertex AI provider-specific settings
+                sig do
+                  params(
+                    location: String,
+                    project: String,
+                    base_url: String,
+                    headers: T::Hash[Symbol, String]
+                  ).returns(T.attached_class)
+                end
+                def self.new(
+                  # Google Cloud location for Vertex AI models
+                  location:,
+                  # Google Cloud project ID for Vertex AI models
+                  project:,
+                  # Base URL for the Vertex AI provider
+                  base_url: nil,
+                  # Custom headers sent with every request to the Vertex AI provider
+                  headers: nil
+                )
+                end
+
+                sig do
+                  override.returns(
+                    {
+                      location: String,
+                      project: String,
+                      base_url: String,
+                      headers: T::Hash[Symbol, String]
+                    }
+                  )
+                end
+                def to_hash
+                end
+              end
+            end
+          end
+
+          class GenericModelConfigObject < Stagehand::Internal::Type::BaseModel
+            OrHash =
+              T.type_alias do
+                T.any(
+                  Stagehand::SessionExtractParams::Options::Model::GenericModelConfigObject,
+                  Stagehand::Internal::AnyHash
+                )
+              end
+
+            # Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            sig { returns(String) }
+            attr_accessor :model_name
+
+            # API key for the model provider
+            sig { returns(T.nilable(String)) }
+            attr_reader :api_key
+
+            sig { params(api_key: String).void }
+            attr_writer :api_key
+
+            # Base URL for the model provider
+            sig { returns(T.nilable(String)) }
+            attr_reader :base_url
+
+            sig { params(base_url: String).void }
+            attr_writer :base_url
+
+            # Custom headers sent with every request to the model provider
+            sig { returns(T.nilable(T::Hash[Symbol, String])) }
+            attr_reader :headers
+
+            sig { params(headers: T::Hash[Symbol, String]).void }
+            attr_writer :headers
+
+            # AI provider for the model (or provide a baseURL endpoint instead)
+            sig do
+              returns(
+                T.nilable(
+                  Stagehand::SessionExtractParams::Options::Model::GenericModelConfigObject::Provider::OrSymbol
+                )
+              )
+            end
+            attr_reader :provider
+
+            sig do
+              params(
+                provider:
+                  Stagehand::SessionExtractParams::Options::Model::GenericModelConfigObject::Provider::OrSymbol
+              ).void
+            end
+            attr_writer :provider
+
+            sig do
+              params(
+                model_name: String,
+                api_key: String,
+                base_url: String,
+                headers: T::Hash[Symbol, String],
+                provider:
+                  Stagehand::SessionExtractParams::Options::Model::GenericModelConfigObject::Provider::OrSymbol
+              ).returns(T.attached_class)
+            end
+            def self.new(
+              # Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+              model_name:,
+              # API key for the model provider
+              api_key: nil,
+              # Base URL for the model provider
+              base_url: nil,
+              # Custom headers sent with every request to the model provider
+              headers: nil,
+              # AI provider for the model (or provide a baseURL endpoint instead)
+              provider: nil
+            )
+            end
+
+            sig do
+              override.returns(
+                {
+                  model_name: String,
+                  api_key: String,
+                  base_url: String,
+                  headers: T::Hash[Symbol, String],
+                  provider:
+                    Stagehand::SessionExtractParams::Options::Model::GenericModelConfigObject::Provider::OrSymbol
+                }
+              )
+            end
+            def to_hash
+            end
+
+            # AI provider for the model (or provide a baseURL endpoint instead)
+            module Provider
+              extend Stagehand::Internal::Type::Enum
+
+              TaggedSymbol =
+                T.type_alias do
+                  T.all(
+                    Symbol,
+                    Stagehand::SessionExtractParams::Options::Model::GenericModelConfigObject::Provider
+                  )
+                end
+              OrSymbol = T.type_alias { T.any(Symbol, String) }
+
+              OPENAI =
+                T.let(
+                  :openai,
+                  Stagehand::SessionExtractParams::Options::Model::GenericModelConfigObject::Provider::TaggedSymbol
+                )
+              ANTHROPIC =
+                T.let(
+                  :anthropic,
+                  Stagehand::SessionExtractParams::Options::Model::GenericModelConfigObject::Provider::TaggedSymbol
+                )
+              GOOGLE =
+                T.let(
+                  :google,
+                  Stagehand::SessionExtractParams::Options::Model::GenericModelConfigObject::Provider::TaggedSymbol
+                )
+              MICROSOFT =
+                T.let(
+                  :microsoft,
+                  Stagehand::SessionExtractParams::Options::Model::GenericModelConfigObject::Provider::TaggedSymbol
+                )
+              BEDROCK =
+                T.let(
+                  :bedrock,
+                  Stagehand::SessionExtractParams::Options::Model::GenericModelConfigObject::Provider::TaggedSymbol
+                )
+
+              sig do
+                override.returns(
+                  T::Array[
+                    Stagehand::SessionExtractParams::Options::Model::GenericModelConfigObject::Provider::TaggedSymbol
+                  ]
+                )
+              end
+              def self.values
+              end
+            end
+          end
 
           sig do
             override.returns(
diff --git a/rbi/stagehand/models/session_observe_params.rbi b/rbi/stagehand/models/session_observe_params.rbi
index ba48ed4..8bde0a2 100644
--- a/rbi/stagehand/models/session_observe_params.rbi
+++ b/rbi/stagehand/models/session_observe_params.rbi
@@ -100,12 +100,36 @@ module Stagehand
             )
           end
 
+        # Selectors for elements and subtrees that should be excluded from observation
+        sig { returns(T.nilable(T::Array[String])) }
+        attr_reader :ignore_selectors
+
+        sig { params(ignore_selectors: T::Array[String]).void }
+        attr_writer :ignore_selectors
+
         # Model configuration object or model name string (e.g., 'openai/gpt-5-nano')
-        sig { returns(T.nilable(T.any(Stagehand::ModelConfig, String))) }
+        sig do
+          returns(
+            T.nilable(
+              T.any(
+                Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject,
+                Stagehand::SessionObserveParams::Options::Model::GenericModelConfigObject,
+                String
+              )
+            )
+          )
+        end
         attr_reader :model
 
         sig do
-          params(model: T.any(Stagehand::ModelConfig::OrHash, String)).void
+          params(
+            model:
+              T.any(
+                Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::OrHash,
+                Stagehand::SessionObserveParams::Options::Model::GenericModelConfigObject::OrHash,
+                String
+              )
+          ).void
         end
         attr_writer :model
 
@@ -161,7 +185,13 @@ module Stagehand
 
         sig do
           params(
-            model: T.any(Stagehand::ModelConfig::OrHash, String),
+            ignore_selectors: T::Array[String],
+            model:
+              T.any(
+                Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::OrHash,
+                Stagehand::SessionObserveParams::Options::Model::GenericModelConfigObject::OrHash,
+                String
+              ),
             selector: String,
             timeout: Float,
             variables:
@@ -177,6 +207,8 @@ module Stagehand
           ).returns(T.attached_class)
         end
         def self.new(
+          # Selectors for elements and subtrees that should be excluded from observation
+          ignore_selectors: nil,
           # Model configuration object or model name string (e.g., 'openai/gpt-5-nano')
           model: nil,
           # CSS selector to scope observation to a specific element
@@ -193,7 +225,13 @@ module Stagehand
         sig do
           override.returns(
             {
-              model: T.any(Stagehand::ModelConfig, String),
+              ignore_selectors: T::Array[String],
+              model:
+                T.any(
+                  Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject,
+                  Stagehand::SessionObserveParams::Options::Model::GenericModelConfigObject,
+                  String
+                ),
               selector: String,
               timeout: Float,
               variables:
@@ -216,7 +254,682 @@ module Stagehand
         module Model
           extend Stagehand::Internal::Type::Union
 
-          Variants = T.type_alias { T.any(Stagehand::ModelConfig, String) }
+          Variants =
+            T.type_alias do
+              T.any(
+                Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject,
+                Stagehand::SessionObserveParams::Options::Model::GenericModelConfigObject,
+                String
+              )
+            end
+
+          class VertexModelConfigObject < Stagehand::Internal::Type::BaseModel
+            OrHash =
+              T.type_alias do
+                T.any(
+                  Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject,
+                  Stagehand::Internal::AnyHash
+                )
+              end
+
+            # Vertex provider authentication configuration
+            sig do
+              returns(
+                Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth
+              )
+            end
+            attr_reader :auth
+
+            sig do
+              params(
+                auth:
+                  Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::OrHash
+              ).void
+            end
+            attr_writer :auth
+
+            # Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            sig { returns(String) }
+            attr_accessor :model_name
+
+            # Vertex AI model provider
+            sig { returns(Symbol) }
+            attr_accessor :provider
+
+            # Vertex provider-specific model configuration
+            sig do
+              returns(
+                Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::ProviderOptions
+              )
+            end
+            attr_reader :provider_options
+
+            sig do
+              params(
+                provider_options:
+                  Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::ProviderOptions::OrHash
+              ).void
+            end
+            attr_writer :provider_options
+
+            # API key for the model provider
+            sig { returns(T.nilable(String)) }
+            attr_reader :api_key
+
+            sig { params(api_key: String).void }
+            attr_writer :api_key
+
+            # Base URL for the model provider
+            sig { returns(T.nilable(String)) }
+            attr_reader :base_url
+
+            sig { params(base_url: String).void }
+            attr_writer :base_url
+
+            # Custom headers sent with every request to the model provider
+            sig { returns(T.nilable(T::Hash[Symbol, String])) }
+            attr_reader :headers
+
+            sig { params(headers: T::Hash[Symbol, String]).void }
+            attr_writer :headers
+
+            sig do
+              params(
+                auth:
+                  Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::OrHash,
+                model_name: String,
+                provider_options:
+                  Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::ProviderOptions::OrHash,
+                api_key: String,
+                base_url: String,
+                headers: T::Hash[Symbol, String],
+                provider: Symbol
+              ).returns(T.attached_class)
+            end
+            def self.new(
+              # Vertex provider authentication configuration
+              auth:,
+              # Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+              model_name:,
+              # Vertex provider-specific model configuration
+              provider_options:,
+              # API key for the model provider
+              api_key: nil,
+              # Base URL for the model provider
+              base_url: nil,
+              # Custom headers sent with every request to the model provider
+              headers: nil,
+              # Vertex AI model provider
+              provider: :vertex
+            )
+            end
+
+            sig do
+              override.returns(
+                {
+                  auth:
+                    Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth,
+                  model_name: String,
+                  provider: Symbol,
+                  provider_options:
+                    Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::ProviderOptions,
+                  api_key: String,
+                  base_url: String,
+                  headers: T::Hash[Symbol, String]
+                }
+              )
+            end
+            def to_hash
+            end
+
+            class Auth < Stagehand::Internal::Type::BaseModel
+              OrHash =
+                T.type_alias do
+                  T.any(
+                    Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth,
+                    Stagehand::Internal::AnyHash
+                  )
+                end
+
+              # Google Cloud service account credentials
+              sig do
+                returns(
+                  Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials
+                )
+              end
+              attr_reader :credentials
+
+              sig do
+                params(
+                  credentials:
+                    Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials::OrHash
+                ).void
+              end
+              attr_writer :credentials
+
+              # Use inline Google Cloud service account credentials for provider authentication
+              sig { returns(Symbol) }
+              attr_accessor :type
+
+              # Google Cloud project ID used by google-auth-library
+              sig { returns(T.nilable(String)) }
+              attr_reader :project_id
+
+              sig { params(project_id: String).void }
+              attr_writer :project_id
+
+              # Google auth scopes for the desired API request
+              sig do
+                returns(
+                  T.nilable(
+                    Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Scopes::Variants
+                  )
+                )
+              end
+              attr_reader :scopes
+
+              sig do
+                params(
+                  scopes:
+                    Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Scopes::Variants
+                ).void
+              end
+              attr_writer :scopes
+
+              # Google Cloud universe domain
+              sig { returns(T.nilable(String)) }
+              attr_reader :universe_domain
+
+              sig { params(universe_domain: String).void }
+              attr_writer :universe_domain
+
+              # Vertex provider authentication configuration
+              sig do
+                params(
+                  credentials:
+                    Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials::OrHash,
+                  project_id: String,
+                  scopes:
+                    Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Scopes::Variants,
+                  universe_domain: String,
+                  type: Symbol
+                ).returns(T.attached_class)
+              end
+              def self.new(
+                # Google Cloud service account credentials
+                credentials:,
+                # Google Cloud project ID used by google-auth-library
+                project_id: nil,
+                # Google auth scopes for the desired API request
+                scopes: nil,
+                # Google Cloud universe domain
+                universe_domain: nil,
+                # Use inline Google Cloud service account credentials for provider authentication
+                type: :googleServiceAccount
+              )
+              end
+
+              sig do
+                override.returns(
+                  {
+                    credentials:
+                      Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials,
+                    type: Symbol,
+                    project_id: String,
+                    scopes:
+                      Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Scopes::Variants,
+                    universe_domain: String
+                  }
+                )
+              end
+              def to_hash
+              end
+
+              class Credentials < Stagehand::Internal::Type::BaseModel
+                OrHash =
+                  T.type_alias do
+                    T.any(
+                      Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials,
+                      Stagehand::Internal::AnyHash
+                    )
+                  end
+
+                sig { returns(String) }
+                attr_accessor :client_email
+
+                sig { returns(String) }
+                attr_accessor :private_key
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :auth_provider_x509_cert_url
+
+                sig { params(auth_provider_x509_cert_url: String).void }
+                attr_writer :auth_provider_x509_cert_url
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :auth_uri
+
+                sig { params(auth_uri: String).void }
+                attr_writer :auth_uri
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :client_id
+
+                sig { params(client_id: String).void }
+                attr_writer :client_id
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :client_x509_cert_url
+
+                sig { params(client_x509_cert_url: String).void }
+                attr_writer :client_x509_cert_url
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :private_key_id
+
+                sig { params(private_key_id: String).void }
+                attr_writer :private_key_id
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :project_id
+
+                sig { params(project_id: String).void }
+                attr_writer :project_id
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :token_uri
+
+                sig { params(token_uri: String).void }
+                attr_writer :token_uri
+
+                sig do
+                  returns(
+                    T.nilable(
+                      Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type::OrSymbol
+                    )
+                  )
+                end
+                attr_reader :type
+
+                sig do
+                  params(
+                    type:
+                      Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type::OrSymbol
+                  ).void
+                end
+                attr_writer :type
+
+                sig { returns(T.nilable(String)) }
+                attr_reader :universe_domain
+
+                sig { params(universe_domain: String).void }
+                attr_writer :universe_domain
+
+                # Google Cloud service account credentials
+                sig do
+                  params(
+                    client_email: String,
+                    private_key: String,
+                    auth_provider_x509_cert_url: String,
+                    auth_uri: String,
+                    client_id: String,
+                    client_x509_cert_url: String,
+                    private_key_id: String,
+                    project_id: String,
+                    token_uri: String,
+                    type:
+                      Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type::OrSymbol,
+                    universe_domain: String
+                  ).returns(T.attached_class)
+                end
+                def self.new(
+                  client_email:,
+                  private_key:,
+                  auth_provider_x509_cert_url: nil,
+                  auth_uri: nil,
+                  client_id: nil,
+                  client_x509_cert_url: nil,
+                  private_key_id: nil,
+                  project_id: nil,
+                  token_uri: nil,
+                  type: nil,
+                  universe_domain: nil
+                )
+                end
+
+                sig do
+                  override.returns(
+                    {
+                      client_email: String,
+                      private_key: String,
+                      auth_provider_x509_cert_url: String,
+                      auth_uri: String,
+                      client_id: String,
+                      client_x509_cert_url: String,
+                      private_key_id: String,
+                      project_id: String,
+                      token_uri: String,
+                      type:
+                        Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type::OrSymbol,
+                      universe_domain: String
+                    }
+                  )
+                end
+                def to_hash
+                end
+
+                module Type
+                  extend Stagehand::Internal::Type::Enum
+
+                  TaggedSymbol =
+                    T.type_alias do
+                      T.all(
+                        Symbol,
+                        Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type
+                      )
+                    end
+                  OrSymbol = T.type_alias { T.any(Symbol, String) }
+
+                  SERVICE_ACCOUNT =
+                    T.let(
+                      :service_account,
+                      Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type::TaggedSymbol
+                    )
+
+                  sig do
+                    override.returns(
+                      T::Array[
+                        Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials::Type::TaggedSymbol
+                      ]
+                    )
+                  end
+                  def self.values
+                  end
+                end
+              end
+
+              # Google auth scopes for the desired API request
+              module Scopes
+                extend Stagehand::Internal::Type::Union
+
+                Variants = T.type_alias { T.any(String, T::Array[String]) }
+
+                sig do
+                  override.returns(
+                    T::Array[
+                      Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Scopes::Variants
+                    ]
+                  )
+                end
+                def self.variants
+                end
+
+                StringArray =
+                  T.let(
+                    Stagehand::Internal::Type::ArrayOf[String],
+                    Stagehand::Internal::Type::Converter
+                  )
+              end
+            end
+
+            class ProviderOptions < Stagehand::Internal::Type::BaseModel
+              OrHash =
+                T.type_alias do
+                  T.any(
+                    Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::ProviderOptions,
+                    Stagehand::Internal::AnyHash
+                  )
+                end
+
+              # Vertex AI provider-specific settings
+              sig do
+                returns(
+                  Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex
+                )
+              end
+              attr_reader :vertex
+
+              sig do
+                params(
+                  vertex:
+                    Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex::OrHash
+                ).void
+              end
+              attr_writer :vertex
+
+              # Vertex provider-specific model configuration
+              sig do
+                params(
+                  vertex:
+                    Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex::OrHash
+                ).returns(T.attached_class)
+              end
+              def self.new(
+                # Vertex AI provider-specific settings
+                vertex:
+              )
+              end
+
+              sig do
+                override.returns(
+                  {
+                    vertex:
+                      Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex
+                  }
+                )
+              end
+              def to_hash
+              end
+
+              class Vertex < Stagehand::Internal::Type::BaseModel
+                OrHash =
+                  T.type_alias do
+                    T.any(
+                      Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex,
+                      Stagehand::Internal::AnyHash
+                    )
+                  end
+
+                # Google Cloud location for Vertex AI models
+                sig { returns(String) }
+                attr_accessor :location
+
+                # Google Cloud project ID for Vertex AI models
+                sig { returns(String) }
+                attr_accessor :project
+
+                # Base URL for the Vertex AI provider
+                sig { returns(T.nilable(String)) }
+                attr_reader :base_url
+
+                sig { params(base_url: String).void }
+                attr_writer :base_url
+
+                # Custom headers sent with every request to the Vertex AI provider
+                sig { returns(T.nilable(T::Hash[Symbol, String])) }
+                attr_reader :headers
+
+                sig { params(headers: T::Hash[Symbol, String]).void }
+                attr_writer :headers
+
+                # Vertex AI provider-specific settings
+                sig do
+                  params(
+                    location: String,
+                    project: String,
+                    base_url: String,
+                    headers: T::Hash[Symbol, String]
+                  ).returns(T.attached_class)
+                end
+                def self.new(
+                  # Google Cloud location for Vertex AI models
+                  location:,
+                  # Google Cloud project ID for Vertex AI models
+                  project:,
+                  # Base URL for the Vertex AI provider
+                  base_url: nil,
+                  # Custom headers sent with every request to the Vertex AI provider
+                  headers: nil
+                )
+                end
+
+                sig do
+                  override.returns(
+                    {
+                      location: String,
+                      project: String,
+                      base_url: String,
+                      headers: T::Hash[Symbol, String]
+                    }
+                  )
+                end
+                def to_hash
+                end
+              end
+            end
+          end
+
+          class GenericModelConfigObject < Stagehand::Internal::Type::BaseModel
+            OrHash =
+              T.type_alias do
+                T.any(
+                  Stagehand::SessionObserveParams::Options::Model::GenericModelConfigObject,
+                  Stagehand::Internal::AnyHash
+                )
+              end
+
+            # Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+            sig { returns(String) }
+            attr_accessor :model_name
+
+            # API key for the model provider
+            sig { returns(T.nilable(String)) }
+            attr_reader :api_key
+
+            sig { params(api_key: String).void }
+            attr_writer :api_key
+
+            # Base URL for the model provider
+            sig { returns(T.nilable(String)) }
+            attr_reader :base_url
+
+            sig { params(base_url: String).void }
+            attr_writer :base_url
+
+            # Custom headers sent with every request to the model provider
+            sig { returns(T.nilable(T::Hash[Symbol, String])) }
+            attr_reader :headers
+
+            sig { params(headers: T::Hash[Symbol, String]).void }
+            attr_writer :headers
+
+            # AI provider for the model (or provide a baseURL endpoint instead)
+            sig do
+              returns(
+                T.nilable(
+                  Stagehand::SessionObserveParams::Options::Model::GenericModelConfigObject::Provider::OrSymbol
+                )
+              )
+            end
+            attr_reader :provider
+
+            sig do
+              params(
+                provider:
+                  Stagehand::SessionObserveParams::Options::Model::GenericModelConfigObject::Provider::OrSymbol
+              ).void
+            end
+            attr_writer :provider
+
+            sig do
+              params(
+                model_name: String,
+                api_key: String,
+                base_url: String,
+                headers: T::Hash[Symbol, String],
+                provider:
+                  Stagehand::SessionObserveParams::Options::Model::GenericModelConfigObject::Provider::OrSymbol
+              ).returns(T.attached_class)
+            end
+            def self.new(
+              # Model name string with provider prefix (e.g., 'openai/gpt-5-nano')
+              model_name:,
+              # API key for the model provider
+              api_key: nil,
+              # Base URL for the model provider
+              base_url: nil,
+              # Custom headers sent with every request to the model provider
+              headers: nil,
+              # AI provider for the model (or provide a baseURL endpoint instead)
+              provider: nil
+            )
+            end
+
+            sig do
+              override.returns(
+                {
+                  model_name: String,
+                  api_key: String,
+                  base_url: String,
+                  headers: T::Hash[Symbol, String],
+                  provider:
+                    Stagehand::SessionObserveParams::Options::Model::GenericModelConfigObject::Provider::OrSymbol
+                }
+              )
+            end
+            def to_hash
+            end
+
+            # AI provider for the model (or provide a baseURL endpoint instead)
+            module Provider
+              extend Stagehand::Internal::Type::Enum
+
+              TaggedSymbol =
+                T.type_alias do
+                  T.all(
+                    Symbol,
+                    Stagehand::SessionObserveParams::Options::Model::GenericModelConfigObject::Provider
+                  )
+                end
+              OrSymbol = T.type_alias { T.any(Symbol, String) }
+
+              OPENAI =
+                T.let(
+                  :openai,
+                  Stagehand::SessionObserveParams::Options::Model::GenericModelConfigObject::Provider::TaggedSymbol
+                )
+              ANTHROPIC =
+                T.let(
+                  :anthropic,
+                  Stagehand::SessionObserveParams::Options::Model::GenericModelConfigObject::Provider::TaggedSymbol
+                )
+              GOOGLE =
+                T.let(
+                  :google,
+                  Stagehand::SessionObserveParams::Options::Model::GenericModelConfigObject::Provider::TaggedSymbol
+                )
+              MICROSOFT =
+                T.let(
+                  :microsoft,
+                  Stagehand::SessionObserveParams::Options::Model::GenericModelConfigObject::Provider::TaggedSymbol
+                )
+              BEDROCK =
+                T.let(
+                  :bedrock,
+                  Stagehand::SessionObserveParams::Options::Model::GenericModelConfigObject::Provider::TaggedSymbol
+                )
+
+              sig do
+                override.returns(
+                  T::Array[
+                    Stagehand::SessionObserveParams::Options::Model::GenericModelConfigObject::Provider::TaggedSymbol
+                  ]
+                )
+              end
+              def self.values
+              end
+            end
+          end
 
           sig do
             override.returns(
diff --git a/sig/stagehand/models.rbs b/sig/stagehand/models.rbs
index b1942c9..2968f19 100644
--- a/sig/stagehand/models.rbs
+++ b/sig/stagehand/models.rbs
@@ -1,7 +1,7 @@
 module Stagehand
   class Action = Stagehand::Models::Action
 
-  class ModelConfig = Stagehand::Models::ModelConfig
+  module ModelConfig = Stagehand::Models::ModelConfig
 
   class SessionActParams = Stagehand::Models::SessionActParams
 
diff --git a/sig/stagehand/models/model_config.rbs b/sig/stagehand/models/model_config.rbs
index 60d3ebf..7962f75 100644
--- a/sig/stagehand/models/model_config.rbs
+++ b/sig/stagehand/models/model_config.rbs
@@ -1,64 +1,332 @@
 module Stagehand
   module Models
     type model_config =
-      {
-        model_name: String,
-        api_key: String,
-        base_url: String,
-        headers: ::Hash[Symbol, String],
-        provider: Stagehand::Models::ModelConfig::provider
-      }
+      Stagehand::ModelConfig::VertexModelConfigObject
+      | Stagehand::ModelConfig::GenericModelConfigObject
 
-    class ModelConfig < Stagehand::Internal::Type::BaseModel
-      attr_accessor model_name: String
+    module ModelConfig
+      extend Stagehand::Internal::Type::Union
 
-      attr_reader api_key: String?
+      type vertex_model_config_object =
+        {
+          auth: Stagehand::ModelConfig::VertexModelConfigObject::Auth,
+          model_name: String,
+          provider: :vertex,
+          provider_options: Stagehand::ModelConfig::VertexModelConfigObject::ProviderOptions,
+          api_key: String,
+          base_url: String,
+          headers: ::Hash[Symbol, String]
+        }
 
-      def api_key=: (String) -> String
+      class VertexModelConfigObject < Stagehand::Internal::Type::BaseModel
+        attr_accessor auth: Stagehand::ModelConfig::VertexModelConfigObject::Auth
 
-      attr_reader base_url: String?
+        attr_accessor model_name: String
 
-      def base_url=: (String) -> String
+        attr_accessor provider: :vertex
 
-      attr_reader headers: ::Hash[Symbol, String]?
+        attr_accessor provider_options: Stagehand::ModelConfig::VertexModelConfigObject::ProviderOptions
 
-      def headers=: (::Hash[Symbol, String]) -> ::Hash[Symbol, String]
+        attr_reader api_key: String?
 
-      attr_reader provider: Stagehand::Models::ModelConfig::provider?
+        def api_key=: (String) -> String
 
-      def provider=: (
-        Stagehand::Models::ModelConfig::provider
-      ) -> Stagehand::Models::ModelConfig::provider
+        attr_reader base_url: String?
 
-      def initialize: (
-        model_name: String,
-        ?api_key: String,
-        ?base_url: String,
-        ?headers: ::Hash[Symbol, String],
-        ?provider: Stagehand::Models::ModelConfig::provider
-      ) -> void
+        def base_url=: (String) -> String
 
-      def to_hash: -> {
-        model_name: String,
-        api_key: String,
-        base_url: String,
-        headers: ::Hash[Symbol, String],
-        provider: Stagehand::Models::ModelConfig::provider
-      }
+        attr_reader headers: ::Hash[Symbol, String]?
 
-      type provider = :openai | :anthropic | :google | :microsoft | :bedrock
+        def headers=: (::Hash[Symbol, String]) -> ::Hash[Symbol, String]
 
-      module Provider
-        extend Stagehand::Internal::Type::Enum
+        def initialize: (
+          auth: Stagehand::ModelConfig::VertexModelConfigObject::Auth,
+          model_name: String,
+          provider_options: Stagehand::ModelConfig::VertexModelConfigObject::ProviderOptions,
+          ?api_key: String,
+          ?base_url: String,
+          ?headers: ::Hash[Symbol, String],
+          ?provider: :vertex
+        ) -> void
 
-        OPENAI: :openai
-        ANTHROPIC: :anthropic
-        GOOGLE: :google
-        MICROSOFT: :microsoft
-        BEDROCK: :bedrock
+        def to_hash: -> {
+          auth: Stagehand::ModelConfig::VertexModelConfigObject::Auth,
+          model_name: String,
+          provider: :vertex,
+          provider_options: Stagehand::ModelConfig::VertexModelConfigObject::ProviderOptions,
+          api_key: String,
+          base_url: String,
+          headers: ::Hash[Symbol, String]
+        }
 
-        def self?.values: -> ::Array[Stagehand::Models::ModelConfig::provider]
+        type auth =
+          {
+            credentials: Stagehand::ModelConfig::VertexModelConfigObject::Auth::Credentials,
+            type: :googleServiceAccount,
+            project_id: String,
+            scopes: Stagehand::Models::ModelConfig::VertexModelConfigObject::Auth::scopes,
+            universe_domain: String
+          }
+
+        class Auth < Stagehand::Internal::Type::BaseModel
+          attr_accessor credentials: Stagehand::ModelConfig::VertexModelConfigObject::Auth::Credentials
+
+          attr_accessor type: :googleServiceAccount
+
+          attr_reader project_id: String?
+
+          def project_id=: (String) -> String
+
+          attr_reader scopes: Stagehand::Models::ModelConfig::VertexModelConfigObject::Auth::scopes?
+
+          def scopes=: (
+            Stagehand::Models::ModelConfig::VertexModelConfigObject::Auth::scopes
+          ) -> Stagehand::Models::ModelConfig::VertexModelConfigObject::Auth::scopes
+
+          attr_reader universe_domain: String?
+
+          def universe_domain=: (String) -> String
+
+          def initialize: (
+            credentials: Stagehand::ModelConfig::VertexModelConfigObject::Auth::Credentials,
+            ?project_id: String,
+            ?scopes: Stagehand::Models::ModelConfig::VertexModelConfigObject::Auth::scopes,
+            ?universe_domain: String,
+            ?type: :googleServiceAccount
+          ) -> void
+
+          def to_hash: -> {
+            credentials: Stagehand::ModelConfig::VertexModelConfigObject::Auth::Credentials,
+            type: :googleServiceAccount,
+            project_id: String,
+            scopes: Stagehand::Models::ModelConfig::VertexModelConfigObject::Auth::scopes,
+            universe_domain: String
+          }
+
+          type credentials =
+            {
+              client_email: String,
+              private_key: String,
+              :auth_provider_x509_cert_url => String,
+              auth_uri: String,
+              client_id: String,
+              :client_x509_cert_url => String,
+              private_key_id: String,
+              project_id: String,
+              token_uri: String,
+              type: Stagehand::Models::ModelConfig::VertexModelConfigObject::Auth::Credentials::type_,
+              universe_domain: String
+            }
+
+          class Credentials < Stagehand::Internal::Type::BaseModel
+            attr_accessor client_email: String
+
+            attr_accessor private_key: String
+
+            attr_reader auth_provider_x509_cert_url: String?
+
+            def auth_provider_x509_cert_url=: (String) -> String
+
+            attr_reader auth_uri: String?
+
+            def auth_uri=: (String) -> String
+
+            attr_reader client_id: String?
+
+            def client_id=: (String) -> String
+
+            attr_reader client_x509_cert_url: String?
+
+            def client_x509_cert_url=: (String) -> String
+
+            attr_reader private_key_id: String?
+
+            def private_key_id=: (String) -> String
+
+            attr_reader project_id: String?
+
+            def project_id=: (String) -> String
+
+            attr_reader token_uri: String?
+
+            def token_uri=: (String) -> String
+
+            attr_reader type: Stagehand::Models::ModelConfig::VertexModelConfigObject::Auth::Credentials::type_?
+
+            def type=: (
+              Stagehand::Models::ModelConfig::VertexModelConfigObject::Auth::Credentials::type_
+            ) -> Stagehand::Models::ModelConfig::VertexModelConfigObject::Auth::Credentials::type_
+
+            attr_reader universe_domain: String?
+
+            def universe_domain=: (String) -> String
+
+            def initialize: (
+              client_email: String,
+              private_key: String,
+              ?auth_provider_x509_cert_url: String,
+              ?auth_uri: String,
+              ?client_id: String,
+              ?client_x509_cert_url: String,
+              ?private_key_id: String,
+              ?project_id: String,
+              ?token_uri: String,
+              ?type: Stagehand::Models::ModelConfig::VertexModelConfigObject::Auth::Credentials::type_,
+              ?universe_domain: String
+            ) -> void
+
+            def to_hash: -> {
+              client_email: String,
+              private_key: String,
+              :auth_provider_x509_cert_url => String,
+              auth_uri: String,
+              client_id: String,
+              :client_x509_cert_url => String,
+              private_key_id: String,
+              project_id: String,
+              token_uri: String,
+              type: Stagehand::Models::ModelConfig::VertexModelConfigObject::Auth::Credentials::type_,
+              universe_domain: String
+            }
+
+            type type_ = :service_account
+
+            module Type
+              extend Stagehand::Internal::Type::Enum
+
+              SERVICE_ACCOUNT: :service_account
+
+              def self?.values: -> ::Array[Stagehand::Models::ModelConfig::VertexModelConfigObject::Auth::Credentials::type_]
+            end
+          end
+
+          type scopes = String | ::Array[String]
+
+          module Scopes
+            extend Stagehand::Internal::Type::Union
+
+            def self?.variants: -> ::Array[Stagehand::Models::ModelConfig::VertexModelConfigObject::Auth::scopes]
+
+            StringArray: Stagehand::Internal::Type::Converter
+          end
+        end
+
+        type provider_options =
+          {
+            vertex: Stagehand::ModelConfig::VertexModelConfigObject::ProviderOptions::Vertex
+          }
+
+        class ProviderOptions < Stagehand::Internal::Type::BaseModel
+          attr_accessor vertex: Stagehand::ModelConfig::VertexModelConfigObject::ProviderOptions::Vertex
+
+          def initialize: (
+            vertex: Stagehand::ModelConfig::VertexModelConfigObject::ProviderOptions::Vertex
+          ) -> void
+
+          def to_hash: -> {
+            vertex: Stagehand::ModelConfig::VertexModelConfigObject::ProviderOptions::Vertex
+          }
+
+          type vertex =
+            {
+              location: String,
+              project: String,
+              base_url: String,
+              headers: ::Hash[Symbol, String]
+            }
+
+          class Vertex < Stagehand::Internal::Type::BaseModel
+            attr_accessor location: String
+
+            attr_accessor project: String
+
+            attr_reader base_url: String?
+
+            def base_url=: (String) -> String
+
+            attr_reader headers: ::Hash[Symbol, String]?
+
+            def headers=: (::Hash[Symbol, String]) -> ::Hash[Symbol, String]
+
+            def initialize: (
+              location: String,
+              project: String,
+              ?base_url: String,
+              ?headers: ::Hash[Symbol, String]
+            ) -> void
+
+            def to_hash: -> {
+              location: String,
+              project: String,
+              base_url: String,
+              headers: ::Hash[Symbol, String]
+            }
+          end
+        end
       end
+
+      type generic_model_config_object =
+        {
+          model_name: String,
+          api_key: String,
+          base_url: String,
+          headers: ::Hash[Symbol, String],
+          provider: Stagehand::Models::ModelConfig::GenericModelConfigObject::provider
+        }
+
+      class GenericModelConfigObject < Stagehand::Internal::Type::BaseModel
+        attr_accessor model_name: String
+
+        attr_reader api_key: String?
+
+        def api_key=: (String) -> String
+
+        attr_reader base_url: String?
+
+        def base_url=: (String) -> String
+
+        attr_reader headers: ::Hash[Symbol, String]?
+
+        def headers=: (::Hash[Symbol, String]) -> ::Hash[Symbol, String]
+
+        attr_reader provider: Stagehand::Models::ModelConfig::GenericModelConfigObject::provider?
+
+        def provider=: (
+          Stagehand::Models::ModelConfig::GenericModelConfigObject::provider
+        ) -> Stagehand::Models::ModelConfig::GenericModelConfigObject::provider
+
+        def initialize: (
+          model_name: String,
+          ?api_key: String,
+          ?base_url: String,
+          ?headers: ::Hash[Symbol, String],
+          ?provider: Stagehand::Models::ModelConfig::GenericModelConfigObject::provider
+        ) -> void
+
+        def to_hash: -> {
+          model_name: String,
+          api_key: String,
+          base_url: String,
+          headers: ::Hash[Symbol, String],
+          provider: Stagehand::Models::ModelConfig::GenericModelConfigObject::provider
+        }
+
+        type provider = :openai | :anthropic | :google | :microsoft | :bedrock
+
+        module Provider
+          extend Stagehand::Internal::Type::Enum
+
+          OPENAI: :openai
+          ANTHROPIC: :anthropic
+          GOOGLE: :google
+          MICROSOFT: :microsoft
+          BEDROCK: :bedrock
+
+          def self?.values: -> ::Array[Stagehand::Models::ModelConfig::GenericModelConfigObject::provider]
+        end
+      end
+
+      def self?.variants: -> ::Array[Stagehand::Models::model_config]
     end
   end
 end
diff --git a/sig/stagehand/models/session_act_params.rbs b/sig/stagehand/models/session_act_params.rbs
index 36d79a1..9c40e2b 100644
--- a/sig/stagehand/models/session_act_params.rbs
+++ b/sig/stagehand/models/session_act_params.rbs
@@ -94,11 +94,334 @@ module Stagehand
           variables: ::Hash[Symbol, Stagehand::Models::SessionActParams::Options::variable]
         }
 
-        type model = Stagehand::ModelConfig | String
+        type model =
+          Stagehand::SessionActParams::Options::Model::VertexModelConfigObject
+          | Stagehand::SessionActParams::Options::Model::GenericModelConfigObject
+          | String
 
         module Model
           extend Stagehand::Internal::Type::Union
 
+          type vertex_model_config_object =
+            {
+              auth: Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth,
+              model_name: String,
+              provider: :vertex,
+              provider_options: Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::ProviderOptions,
+              api_key: String,
+              base_url: String,
+              headers: ::Hash[Symbol, String]
+            }
+
+          class VertexModelConfigObject < Stagehand::Internal::Type::BaseModel
+            attr_accessor auth: Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth
+
+            attr_accessor model_name: String
+
+            attr_accessor provider: :vertex
+
+            attr_accessor provider_options: Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::ProviderOptions
+
+            attr_reader api_key: String?
+
+            def api_key=: (String) -> String
+
+            attr_reader base_url: String?
+
+            def base_url=: (String) -> String
+
+            attr_reader headers: ::Hash[Symbol, String]?
+
+            def headers=: (::Hash[Symbol, String]) -> ::Hash[Symbol, String]
+
+            def initialize: (
+              auth: Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth,
+              model_name: String,
+              provider_options: Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::ProviderOptions,
+              ?api_key: String,
+              ?base_url: String,
+              ?headers: ::Hash[Symbol, String],
+              ?provider: :vertex
+            ) -> void
+
+            def to_hash: -> {
+              auth: Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth,
+              model_name: String,
+              provider: :vertex,
+              provider_options: Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::ProviderOptions,
+              api_key: String,
+              base_url: String,
+              headers: ::Hash[Symbol, String]
+            }
+
+            type auth =
+              {
+                credentials: Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials,
+                type: :googleServiceAccount,
+                project_id: String,
+                scopes: Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::Auth::scopes,
+                universe_domain: String
+              }
+
+            class Auth < Stagehand::Internal::Type::BaseModel
+              attr_accessor credentials: Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials
+
+              attr_accessor type: :googleServiceAccount
+
+              attr_reader project_id: String?
+
+              def project_id=: (String) -> String
+
+              attr_reader scopes: Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::Auth::scopes?
+
+              def scopes=: (
+                Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::Auth::scopes
+              ) -> Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::Auth::scopes
+
+              attr_reader universe_domain: String?
+
+              def universe_domain=: (String) -> String
+
+              def initialize: (
+                credentials: Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials,
+                ?project_id: String,
+                ?scopes: Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::Auth::scopes,
+                ?universe_domain: String,
+                ?type: :googleServiceAccount
+              ) -> void
+
+              def to_hash: -> {
+                credentials: Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials,
+                type: :googleServiceAccount,
+                project_id: String,
+                scopes: Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::Auth::scopes,
+                universe_domain: String
+              }
+
+              type credentials =
+                {
+                  client_email: String,
+                  private_key: String,
+                  :auth_provider_x509_cert_url => String,
+                  auth_uri: String,
+                  client_id: String,
+                  :client_x509_cert_url => String,
+                  private_key_id: String,
+                  project_id: String,
+                  token_uri: String,
+                  type: Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials::type_,
+                  universe_domain: String
+                }
+
+              class Credentials < Stagehand::Internal::Type::BaseModel
+                attr_accessor client_email: String
+
+                attr_accessor private_key: String
+
+                attr_reader auth_provider_x509_cert_url: String?
+
+                def auth_provider_x509_cert_url=: (String) -> String
+
+                attr_reader auth_uri: String?
+
+                def auth_uri=: (String) -> String
+
+                attr_reader client_id: String?
+
+                def client_id=: (String) -> String
+
+                attr_reader client_x509_cert_url: String?
+
+                def client_x509_cert_url=: (String) -> String
+
+                attr_reader private_key_id: String?
+
+                def private_key_id=: (String) -> String
+
+                attr_reader project_id: String?
+
+                def project_id=: (String) -> String
+
+                attr_reader token_uri: String?
+
+                def token_uri=: (String) -> String
+
+                attr_reader type: Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials::type_?
+
+                def type=: (
+                  Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials::type_
+                ) -> Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials::type_
+
+                attr_reader universe_domain: String?
+
+                def universe_domain=: (String) -> String
+
+                def initialize: (
+                  client_email: String,
+                  private_key: String,
+                  ?auth_provider_x509_cert_url: String,
+                  ?auth_uri: String,
+                  ?client_id: String,
+                  ?client_x509_cert_url: String,
+                  ?private_key_id: String,
+                  ?project_id: String,
+                  ?token_uri: String,
+                  ?type: Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials::type_,
+                  ?universe_domain: String
+                ) -> void
+
+                def to_hash: -> {
+                  client_email: String,
+                  private_key: String,
+                  :auth_provider_x509_cert_url => String,
+                  auth_uri: String,
+                  client_id: String,
+                  :client_x509_cert_url => String,
+                  private_key_id: String,
+                  project_id: String,
+                  token_uri: String,
+                  type: Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials::type_,
+                  universe_domain: String
+                }
+
+                type type_ = :service_account
+
+                module Type
+                  extend Stagehand::Internal::Type::Enum
+
+                  SERVICE_ACCOUNT: :service_account
+
+                  def self?.values: -> ::Array[Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::Auth::Credentials::type_]
+                end
+              end
+
+              type scopes = String | ::Array[String]
+
+              module Scopes
+                extend Stagehand::Internal::Type::Union
+
+                def self?.variants: -> ::Array[Stagehand::Models::SessionActParams::Options::Model::VertexModelConfigObject::Auth::scopes]
+
+                StringArray: Stagehand::Internal::Type::Converter
+              end
+            end
+
+            type provider_options =
+              {
+                vertex: Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex
+              }
+
+            class ProviderOptions < Stagehand::Internal::Type::BaseModel
+              attr_accessor vertex: Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex
+
+              def initialize: (
+                vertex: Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex
+              ) -> void
+
+              def to_hash: -> {
+                vertex: Stagehand::SessionActParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex
+              }
+
+              type vertex =
+                {
+                  location: String,
+                  project: String,
+                  base_url: String,
+                  headers: ::Hash[Symbol, String]
+                }
+
+              class Vertex < Stagehand::Internal::Type::BaseModel
+                attr_accessor location: String
+
+                attr_accessor project: String
+
+                attr_reader base_url: String?
+
+                def base_url=: (String) -> String
+
+                attr_reader headers: ::Hash[Symbol, String]?
+
+                def headers=: (::Hash[Symbol, String]) -> ::Hash[Symbol, String]
+
+                def initialize: (
+                  location: String,
+                  project: String,
+                  ?base_url: String,
+                  ?headers: ::Hash[Symbol, String]
+                ) -> void
+
+                def to_hash: -> {
+                  location: String,
+                  project: String,
+                  base_url: String,
+                  headers: ::Hash[Symbol, String]
+                }
+              end
+            end
+          end
+
+          type generic_model_config_object =
+            {
+              model_name: String,
+              api_key: String,
+              base_url: String,
+              headers: ::Hash[Symbol, String],
+              provider: Stagehand::Models::SessionActParams::Options::Model::GenericModelConfigObject::provider
+            }
+
+          class GenericModelConfigObject < Stagehand::Internal::Type::BaseModel
+            attr_accessor model_name: String
+
+            attr_reader api_key: String?
+
+            def api_key=: (String) -> String
+
+            attr_reader base_url: String?
+
+            def base_url=: (String) -> String
+
+            attr_reader headers: ::Hash[Symbol, String]?
+
+            def headers=: (::Hash[Symbol, String]) -> ::Hash[Symbol, String]
+
+            attr_reader provider: Stagehand::Models::SessionActParams::Options::Model::GenericModelConfigObject::provider?
+
+            def provider=: (
+              Stagehand::Models::SessionActParams::Options::Model::GenericModelConfigObject::provider
+            ) -> Stagehand::Models::SessionActParams::Options::Model::GenericModelConfigObject::provider
+
+            def initialize: (
+              model_name: String,
+              ?api_key: String,
+              ?base_url: String,
+              ?headers: ::Hash[Symbol, String],
+              ?provider: Stagehand::Models::SessionActParams::Options::Model::GenericModelConfigObject::provider
+            ) -> void
+
+            def to_hash: -> {
+              model_name: String,
+              api_key: String,
+              base_url: String,
+              headers: ::Hash[Symbol, String],
+              provider: Stagehand::Models::SessionActParams::Options::Model::GenericModelConfigObject::provider
+            }
+
+            type provider =
+              :openai | :anthropic | :google | :microsoft | :bedrock
+
+            module Provider
+              extend Stagehand::Internal::Type::Enum
+
+              OPENAI: :openai
+              ANTHROPIC: :anthropic
+              GOOGLE: :google
+              MICROSOFT: :microsoft
+              BEDROCK: :bedrock
+
+              def self?.values: -> ::Array[Stagehand::Models::SessionActParams::Options::Model::GenericModelConfigObject::provider]
+            end
+          end
+
           def self?.variants: -> ::Array[Stagehand::Models::SessionActParams::Options::model]
         end
 
diff --git a/sig/stagehand/models/session_execute_params.rbs b/sig/stagehand/models/session_execute_params.rbs
index 068d8eb..06dc774 100644
--- a/sig/stagehand/models/session_execute_params.rbs
+++ b/sig/stagehand/models/session_execute_params.rbs
@@ -114,11 +114,334 @@ module Stagehand
           system_prompt: String
         }
 
-        type execution_model = Stagehand::ModelConfig | String
+        type execution_model =
+          Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject
+          | Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject
+          | String
 
         module ExecutionModel
           extend Stagehand::Internal::Type::Union
 
+          type vertex_model_config_object =
+            {
+              auth: Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth,
+              model_name: String,
+              provider: :vertex,
+              provider_options: Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::ProviderOptions,
+              api_key: String,
+              base_url: String,
+              headers: ::Hash[Symbol, String]
+            }
+
+          class VertexModelConfigObject < Stagehand::Internal::Type::BaseModel
+            attr_accessor auth: Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth
+
+            attr_accessor model_name: String
+
+            attr_accessor provider: :vertex
+
+            attr_accessor provider_options: Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::ProviderOptions
+
+            attr_reader api_key: String?
+
+            def api_key=: (String) -> String
+
+            attr_reader base_url: String?
+
+            def base_url=: (String) -> String
+
+            attr_reader headers: ::Hash[Symbol, String]?
+
+            def headers=: (::Hash[Symbol, String]) -> ::Hash[Symbol, String]
+
+            def initialize: (
+              auth: Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth,
+              model_name: String,
+              provider_options: Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::ProviderOptions,
+              ?api_key: String,
+              ?base_url: String,
+              ?headers: ::Hash[Symbol, String],
+              ?provider: :vertex
+            ) -> void
+
+            def to_hash: -> {
+              auth: Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth,
+              model_name: String,
+              provider: :vertex,
+              provider_options: Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::ProviderOptions,
+              api_key: String,
+              base_url: String,
+              headers: ::Hash[Symbol, String]
+            }
+
+            type auth =
+              {
+                credentials: Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials,
+                type: :googleServiceAccount,
+                project_id: String,
+                scopes: Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::scopes,
+                universe_domain: String
+              }
+
+            class Auth < Stagehand::Internal::Type::BaseModel
+              attr_accessor credentials: Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials
+
+              attr_accessor type: :googleServiceAccount
+
+              attr_reader project_id: String?
+
+              def project_id=: (String) -> String
+
+              attr_reader scopes: Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::scopes?
+
+              def scopes=: (
+                Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::scopes
+              ) -> Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::scopes
+
+              attr_reader universe_domain: String?
+
+              def universe_domain=: (String) -> String
+
+              def initialize: (
+                credentials: Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials,
+                ?project_id: String,
+                ?scopes: Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::scopes,
+                ?universe_domain: String,
+                ?type: :googleServiceAccount
+              ) -> void
+
+              def to_hash: -> {
+                credentials: Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials,
+                type: :googleServiceAccount,
+                project_id: String,
+                scopes: Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::scopes,
+                universe_domain: String
+              }
+
+              type credentials =
+                {
+                  client_email: String,
+                  private_key: String,
+                  :auth_provider_x509_cert_url => String,
+                  auth_uri: String,
+                  client_id: String,
+                  :client_x509_cert_url => String,
+                  private_key_id: String,
+                  project_id: String,
+                  token_uri: String,
+                  type: Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials::type_,
+                  universe_domain: String
+                }
+
+              class Credentials < Stagehand::Internal::Type::BaseModel
+                attr_accessor client_email: String
+
+                attr_accessor private_key: String
+
+                attr_reader auth_provider_x509_cert_url: String?
+
+                def auth_provider_x509_cert_url=: (String) -> String
+
+                attr_reader auth_uri: String?
+
+                def auth_uri=: (String) -> String
+
+                attr_reader client_id: String?
+
+                def client_id=: (String) -> String
+
+                attr_reader client_x509_cert_url: String?
+
+                def client_x509_cert_url=: (String) -> String
+
+                attr_reader private_key_id: String?
+
+                def private_key_id=: (String) -> String
+
+                attr_reader project_id: String?
+
+                def project_id=: (String) -> String
+
+                attr_reader token_uri: String?
+
+                def token_uri=: (String) -> String
+
+                attr_reader type: Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials::type_?
+
+                def type=: (
+                  Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials::type_
+                ) -> Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials::type_
+
+                attr_reader universe_domain: String?
+
+                def universe_domain=: (String) -> String
+
+                def initialize: (
+                  client_email: String,
+                  private_key: String,
+                  ?auth_provider_x509_cert_url: String,
+                  ?auth_uri: String,
+                  ?client_id: String,
+                  ?client_x509_cert_url: String,
+                  ?private_key_id: String,
+                  ?project_id: String,
+                  ?token_uri: String,
+                  ?type: Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials::type_,
+                  ?universe_domain: String
+                ) -> void
+
+                def to_hash: -> {
+                  client_email: String,
+                  private_key: String,
+                  :auth_provider_x509_cert_url => String,
+                  auth_uri: String,
+                  client_id: String,
+                  :client_x509_cert_url => String,
+                  private_key_id: String,
+                  project_id: String,
+                  token_uri: String,
+                  type: Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials::type_,
+                  universe_domain: String
+                }
+
+                type type_ = :service_account
+
+                module Type
+                  extend Stagehand::Internal::Type::Enum
+
+                  SERVICE_ACCOUNT: :service_account
+
+                  def self?.values: -> ::Array[Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::Credentials::type_]
+                end
+              end
+
+              type scopes = String | ::Array[String]
+
+              module Scopes
+                extend Stagehand::Internal::Type::Union
+
+                def self?.variants: -> ::Array[Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::Auth::scopes]
+
+                StringArray: Stagehand::Internal::Type::Converter
+              end
+            end
+
+            type provider_options =
+              {
+                vertex: Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::ProviderOptions::Vertex
+              }
+
+            class ProviderOptions < Stagehand::Internal::Type::BaseModel
+              attr_accessor vertex: Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::ProviderOptions::Vertex
+
+              def initialize: (
+                vertex: Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::ProviderOptions::Vertex
+              ) -> void
+
+              def to_hash: -> {
+                vertex: Stagehand::SessionExecuteParams::AgentConfig::ExecutionModel::VertexModelConfigObject::ProviderOptions::Vertex
+              }
+
+              type vertex =
+                {
+                  location: String,
+                  project: String,
+                  base_url: String,
+                  headers: ::Hash[Symbol, String]
+                }
+
+              class Vertex < Stagehand::Internal::Type::BaseModel
+                attr_accessor location: String
+
+                attr_accessor project: String
+
+                attr_reader base_url: String?
+
+                def base_url=: (String) -> String
+
+                attr_reader headers: ::Hash[Symbol, String]?
+
+                def headers=: (::Hash[Symbol, String]) -> ::Hash[Symbol, String]
+
+                def initialize: (
+                  location: String,
+                  project: String,
+                  ?base_url: String,
+                  ?headers: ::Hash[Symbol, String]
+                ) -> void
+
+                def to_hash: -> {
+                  location: String,
+                  project: String,
+                  base_url: String,
+                  headers: ::Hash[Symbol, String]
+                }
+              end
+            end
+          end
+
+          type generic_model_config_object =
+            {
+              model_name: String,
+              api_key: String,
+              base_url: String,
+              headers: ::Hash[Symbol, String],
+              provider: Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject::provider
+            }
+
+          class GenericModelConfigObject < Stagehand::Internal::Type::BaseModel
+            attr_accessor model_name: String
+
+            attr_reader api_key: String?
+
+            def api_key=: (String) -> String
+
+            attr_reader base_url: String?
+
+            def base_url=: (String) -> String
+
+            attr_reader headers: ::Hash[Symbol, String]?
+
+            def headers=: (::Hash[Symbol, String]) -> ::Hash[Symbol, String]
+
+            attr_reader provider: Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject::provider?
+
+            def provider=: (
+              Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject::provider
+            ) -> Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject::provider
+
+            def initialize: (
+              model_name: String,
+              ?api_key: String,
+              ?base_url: String,
+              ?headers: ::Hash[Symbol, String],
+              ?provider: Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject::provider
+            ) -> void
+
+            def to_hash: -> {
+              model_name: String,
+              api_key: String,
+              base_url: String,
+              headers: ::Hash[Symbol, String],
+              provider: Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject::provider
+            }
+
+            type provider =
+              :openai | :anthropic | :google | :microsoft | :bedrock
+
+            module Provider
+              extend Stagehand::Internal::Type::Enum
+
+              OPENAI: :openai
+              ANTHROPIC: :anthropic
+              GOOGLE: :google
+              MICROSOFT: :microsoft
+              BEDROCK: :bedrock
+
+              def self?.values: -> ::Array[Stagehand::Models::SessionExecuteParams::AgentConfig::ExecutionModel::GenericModelConfigObject::provider]
+            end
+          end
+
           def self?.variants: -> ::Array[Stagehand::Models::SessionExecuteParams::AgentConfig::execution_model]
         end
 
@@ -134,11 +457,334 @@ module Stagehand
           def self?.values: -> ::Array[Stagehand::Models::SessionExecuteParams::AgentConfig::mode]
         end
 
-        type model = Stagehand::ModelConfig | String
+        type model =
+          Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject
+          | Stagehand::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject
+          | String
 
         module Model
           extend Stagehand::Internal::Type::Union
 
+          type vertex_model_config_object =
+            {
+              auth: Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth,
+              model_name: String,
+              provider: :vertex,
+              provider_options: Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::ProviderOptions,
+              api_key: String,
+              base_url: String,
+              headers: ::Hash[Symbol, String]
+            }
+
+          class VertexModelConfigObject < Stagehand::Internal::Type::BaseModel
+            attr_accessor auth: Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth
+
+            attr_accessor model_name: String
+
+            attr_accessor provider: :vertex
+
+            attr_accessor provider_options: Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::ProviderOptions
+
+            attr_reader api_key: String?
+
+            def api_key=: (String) -> String
+
+            attr_reader base_url: String?
+
+            def base_url=: (String) -> String
+
+            attr_reader headers: ::Hash[Symbol, String]?
+
+            def headers=: (::Hash[Symbol, String]) -> ::Hash[Symbol, String]
+
+            def initialize: (
+              auth: Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth,
+              model_name: String,
+              provider_options: Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::ProviderOptions,
+              ?api_key: String,
+              ?base_url: String,
+              ?headers: ::Hash[Symbol, String],
+              ?provider: :vertex
+            ) -> void
+
+            def to_hash: -> {
+              auth: Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth,
+              model_name: String,
+              provider: :vertex,
+              provider_options: Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::ProviderOptions,
+              api_key: String,
+              base_url: String,
+              headers: ::Hash[Symbol, String]
+            }
+
+            type auth =
+              {
+                credentials: Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials,
+                type: :googleServiceAccount,
+                project_id: String,
+                scopes: Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::scopes,
+                universe_domain: String
+              }
+
+            class Auth < Stagehand::Internal::Type::BaseModel
+              attr_accessor credentials: Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials
+
+              attr_accessor type: :googleServiceAccount
+
+              attr_reader project_id: String?
+
+              def project_id=: (String) -> String
+
+              attr_reader scopes: Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::scopes?
+
+              def scopes=: (
+                Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::scopes
+              ) -> Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::scopes
+
+              attr_reader universe_domain: String?
+
+              def universe_domain=: (String) -> String
+
+              def initialize: (
+                credentials: Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials,
+                ?project_id: String,
+                ?scopes: Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::scopes,
+                ?universe_domain: String,
+                ?type: :googleServiceAccount
+              ) -> void
+
+              def to_hash: -> {
+                credentials: Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials,
+                type: :googleServiceAccount,
+                project_id: String,
+                scopes: Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::scopes,
+                universe_domain: String
+              }
+
+              type credentials =
+                {
+                  client_email: String,
+                  private_key: String,
+                  :auth_provider_x509_cert_url => String,
+                  auth_uri: String,
+                  client_id: String,
+                  :client_x509_cert_url => String,
+                  private_key_id: String,
+                  project_id: String,
+                  token_uri: String,
+                  type: Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials::type_,
+                  universe_domain: String
+                }
+
+              class Credentials < Stagehand::Internal::Type::BaseModel
+                attr_accessor client_email: String
+
+                attr_accessor private_key: String
+
+                attr_reader auth_provider_x509_cert_url: String?
+
+                def auth_provider_x509_cert_url=: (String) -> String
+
+                attr_reader auth_uri: String?
+
+                def auth_uri=: (String) -> String
+
+                attr_reader client_id: String?
+
+                def client_id=: (String) -> String
+
+                attr_reader client_x509_cert_url: String?
+
+                def client_x509_cert_url=: (String) -> String
+
+                attr_reader private_key_id: String?
+
+                def private_key_id=: (String) -> String
+
+                attr_reader project_id: String?
+
+                def project_id=: (String) -> String
+
+                attr_reader token_uri: String?
+
+                def token_uri=: (String) -> String
+
+                attr_reader type: Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials::type_?
+
+                def type=: (
+                  Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials::type_
+                ) -> Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials::type_
+
+                attr_reader universe_domain: String?
+
+                def universe_domain=: (String) -> String
+
+                def initialize: (
+                  client_email: String,
+                  private_key: String,
+                  ?auth_provider_x509_cert_url: String,
+                  ?auth_uri: String,
+                  ?client_id: String,
+                  ?client_x509_cert_url: String,
+                  ?private_key_id: String,
+                  ?project_id: String,
+                  ?token_uri: String,
+                  ?type: Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials::type_,
+                  ?universe_domain: String
+                ) -> void
+
+                def to_hash: -> {
+                  client_email: String,
+                  private_key: String,
+                  :auth_provider_x509_cert_url => String,
+                  auth_uri: String,
+                  client_id: String,
+                  :client_x509_cert_url => String,
+                  private_key_id: String,
+                  project_id: String,
+                  token_uri: String,
+                  type: Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials::type_,
+                  universe_domain: String
+                }
+
+                type type_ = :service_account
+
+                module Type
+                  extend Stagehand::Internal::Type::Enum
+
+                  SERVICE_ACCOUNT: :service_account
+
+                  def self?.values: -> ::Array[Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::Credentials::type_]
+                end
+              end
+
+              type scopes = String | ::Array[String]
+
+              module Scopes
+                extend Stagehand::Internal::Type::Union
+
+                def self?.variants: -> ::Array[Stagehand::Models::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::Auth::scopes]
+
+                StringArray: Stagehand::Internal::Type::Converter
+              end
+            end
+
+            type provider_options =
+              {
+                vertex: Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::ProviderOptions::Vertex
+              }
+
+            class ProviderOptions < Stagehand::Internal::Type::BaseModel
+              attr_accessor vertex: Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::ProviderOptions::Vertex
+
+              def initialize: (
+                vertex: Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::ProviderOptions::Vertex
+              ) -> void
+
+              def to_hash: -> {
+                vertex: Stagehand::SessionExecuteParams::AgentConfig::Model::VertexModelConfigObject::ProviderOptions::Vertex
+              }
+
+              type vertex =
+                {
+                  location: String,
+                  project: String,
+                  base_url: String,
+                  headers: ::Hash[Symbol, String]
+                }
+
+              class Vertex < Stagehand::Internal::Type::BaseModel
+                attr_accessor location: String
+
+                attr_accessor project: String
+
+                attr_reader base_url: String?
+
+                def base_url=: (String) -> String
+
+                attr_reader headers: ::Hash[Symbol, String]?
+
+                def headers=: (::Hash[Symbol, String]) -> ::Hash[Symbol, String]
+
+                def initialize: (
+                  location: String,
+                  project: String,
+                  ?base_url: String,
+                  ?headers: ::Hash[Symbol, String]
+                ) -> void
+
+                def to_hash: -> {
+                  location: String,
+                  project: String,
+                  base_url: String,
+                  headers: ::Hash[Symbol, String]
+                }
+              end
+            end
+          end
+
+          type generic_model_config_object =
+            {
+              model_name: String,
+              api_key: String,
+              base_url: String,
+              headers: ::Hash[Symbol, String],
+              provider: Stagehand::Models::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject::provider
+            }
+
+          class GenericModelConfigObject < Stagehand::Internal::Type::BaseModel
+            attr_accessor model_name: String
+
+            attr_reader api_key: String?
+
+            def api_key=: (String) -> String
+
+            attr_reader base_url: String?
+
+            def base_url=: (String) -> String
+
+            attr_reader headers: ::Hash[Symbol, String]?
+
+            def headers=: (::Hash[Symbol, String]) -> ::Hash[Symbol, String]
+
+            attr_reader provider: Stagehand::Models::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject::provider?
+
+            def provider=: (
+              Stagehand::Models::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject::provider
+            ) -> Stagehand::Models::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject::provider
+
+            def initialize: (
+              model_name: String,
+              ?api_key: String,
+              ?base_url: String,
+              ?headers: ::Hash[Symbol, String],
+              ?provider: Stagehand::Models::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject::provider
+            ) -> void
+
+            def to_hash: -> {
+              model_name: String,
+              api_key: String,
+              base_url: String,
+              headers: ::Hash[Symbol, String],
+              provider: Stagehand::Models::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject::provider
+            }
+
+            type provider =
+              :openai | :anthropic | :google | :microsoft | :bedrock
+
+            module Provider
+              extend Stagehand::Internal::Type::Enum
+
+              OPENAI: :openai
+              ANTHROPIC: :anthropic
+              GOOGLE: :google
+              MICROSOFT: :microsoft
+              BEDROCK: :bedrock
+
+              def self?.values: -> ::Array[Stagehand::Models::SessionExecuteParams::AgentConfig::Model::GenericModelConfigObject::provider]
+            end
+          end
+
           def self?.variants: -> ::Array[Stagehand::Models::SessionExecuteParams::AgentConfig::model]
         end
 
diff --git a/sig/stagehand/models/session_extract_params.rbs b/sig/stagehand/models/session_extract_params.rbs
index aedaaca..7db91e3 100644
--- a/sig/stagehand/models/session_extract_params.rbs
+++ b/sig/stagehand/models/session_extract_params.rbs
@@ -63,6 +63,7 @@ module Stagehand
         {
           ignore_selectors: ::Array[String],
           model: Stagehand::Models::SessionExtractParams::Options::model,
+          screenshot: bool,
           selector: String,
           timeout: Float
         }
@@ -78,6 +79,10 @@ module Stagehand
           Stagehand::Models::SessionExtractParams::Options::model
         ) -> Stagehand::Models::SessionExtractParams::Options::model
 
+        attr_reader screenshot: bool?
+
+        def screenshot=: (bool) -> bool
+
         attr_reader selector: String?
 
         def selector=: (String) -> String
@@ -89,6 +94,7 @@ module Stagehand
         def initialize: (
           ?ignore_selectors: ::Array[String],
           ?model: Stagehand::Models::SessionExtractParams::Options::model,
+          ?screenshot: bool,
           ?selector: String,
           ?timeout: Float
         ) -> void
@@ -96,15 +102,339 @@ module Stagehand
         def to_hash: -> {
           ignore_selectors: ::Array[String],
           model: Stagehand::Models::SessionExtractParams::Options::model,
+          screenshot: bool,
           selector: String,
           timeout: Float
         }
 
-        type model = Stagehand::ModelConfig | String
+        type model =
+          Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject
+          | Stagehand::SessionExtractParams::Options::Model::GenericModelConfigObject
+          | String
 
         module Model
           extend Stagehand::Internal::Type::Union
 
+          type vertex_model_config_object =
+            {
+              auth: Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth,
+              model_name: String,
+              provider: :vertex,
+              provider_options: Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::ProviderOptions,
+              api_key: String,
+              base_url: String,
+              headers: ::Hash[Symbol, String]
+            }
+
+          class VertexModelConfigObject < Stagehand::Internal::Type::BaseModel
+            attr_accessor auth: Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth
+
+            attr_accessor model_name: String
+
+            attr_accessor provider: :vertex
+
+            attr_accessor provider_options: Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::ProviderOptions
+
+            attr_reader api_key: String?
+
+            def api_key=: (String) -> String
+
+            attr_reader base_url: String?
+
+            def base_url=: (String) -> String
+
+            attr_reader headers: ::Hash[Symbol, String]?
+
+            def headers=: (::Hash[Symbol, String]) -> ::Hash[Symbol, String]
+
+            def initialize: (
+              auth: Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth,
+              model_name: String,
+              provider_options: Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::ProviderOptions,
+              ?api_key: String,
+              ?base_url: String,
+              ?headers: ::Hash[Symbol, String],
+              ?provider: :vertex
+            ) -> void
+
+            def to_hash: -> {
+              auth: Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth,
+              model_name: String,
+              provider: :vertex,
+              provider_options: Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::ProviderOptions,
+              api_key: String,
+              base_url: String,
+              headers: ::Hash[Symbol, String]
+            }
+
+            type auth =
+              {
+                credentials: Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials,
+                type: :googleServiceAccount,
+                project_id: String,
+                scopes: Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::scopes,
+                universe_domain: String
+              }
+
+            class Auth < Stagehand::Internal::Type::BaseModel
+              attr_accessor credentials: Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials
+
+              attr_accessor type: :googleServiceAccount
+
+              attr_reader project_id: String?
+
+              def project_id=: (String) -> String
+
+              attr_reader scopes: Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::scopes?
+
+              def scopes=: (
+                Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::scopes
+              ) -> Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::scopes
+
+              attr_reader universe_domain: String?
+
+              def universe_domain=: (String) -> String
+
+              def initialize: (
+                credentials: Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials,
+                ?project_id: String,
+                ?scopes: Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::scopes,
+                ?universe_domain: String,
+                ?type: :googleServiceAccount
+              ) -> void
+
+              def to_hash: -> {
+                credentials: Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials,
+                type: :googleServiceAccount,
+                project_id: String,
+                scopes: Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::scopes,
+                universe_domain: String
+              }
+
+              type credentials =
+                {
+                  client_email: String,
+                  private_key: String,
+                  :auth_provider_x509_cert_url => String,
+                  auth_uri: String,
+                  client_id: String,
+                  :client_x509_cert_url => String,
+                  private_key_id: String,
+                  project_id: String,
+                  token_uri: String,
+                  type: Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials::type_,
+                  universe_domain: String
+                }
+
+              class Credentials < Stagehand::Internal::Type::BaseModel
+                attr_accessor client_email: String
+
+                attr_accessor private_key: String
+
+                attr_reader auth_provider_x509_cert_url: String?
+
+                def auth_provider_x509_cert_url=: (String) -> String
+
+                attr_reader auth_uri: String?
+
+                def auth_uri=: (String) -> String
+
+                attr_reader client_id: String?
+
+                def client_id=: (String) -> String
+
+                attr_reader client_x509_cert_url: String?
+
+                def client_x509_cert_url=: (String) -> String
+
+                attr_reader private_key_id: String?
+
+                def private_key_id=: (String) -> String
+
+                attr_reader project_id: String?
+
+                def project_id=: (String) -> String
+
+                attr_reader token_uri: String?
+
+                def token_uri=: (String) -> String
+
+                attr_reader type: Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials::type_?
+
+                def type=: (
+                  Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials::type_
+                ) -> Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials::type_
+
+                attr_reader universe_domain: String?
+
+                def universe_domain=: (String) -> String
+
+                def initialize: (
+                  client_email: String,
+                  private_key: String,
+                  ?auth_provider_x509_cert_url: String,
+                  ?auth_uri: String,
+                  ?client_id: String,
+                  ?client_x509_cert_url: String,
+                  ?private_key_id: String,
+                  ?project_id: String,
+                  ?token_uri: String,
+                  ?type: Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials::type_,
+                  ?universe_domain: String
+                ) -> void
+
+                def to_hash: -> {
+                  client_email: String,
+                  private_key: String,
+                  :auth_provider_x509_cert_url => String,
+                  auth_uri: String,
+                  client_id: String,
+                  :client_x509_cert_url => String,
+                  private_key_id: String,
+                  project_id: String,
+                  token_uri: String,
+                  type: Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials::type_,
+                  universe_domain: String
+                }
+
+                type type_ = :service_account
+
+                module Type
+                  extend Stagehand::Internal::Type::Enum
+
+                  SERVICE_ACCOUNT: :service_account
+
+                  def self?.values: -> ::Array[Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::Credentials::type_]
+                end
+              end
+
+              type scopes = String | ::Array[String]
+
+              module Scopes
+                extend Stagehand::Internal::Type::Union
+
+                def self?.variants: -> ::Array[Stagehand::Models::SessionExtractParams::Options::Model::VertexModelConfigObject::Auth::scopes]
+
+                StringArray: Stagehand::Internal::Type::Converter
+              end
+            end
+
+            type provider_options =
+              {
+                vertex: Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex
+              }
+
+            class ProviderOptions < Stagehand::Internal::Type::BaseModel
+              attr_accessor vertex: Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex
+
+              def initialize: (
+                vertex: Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex
+              ) -> void
+
+              def to_hash: -> {
+                vertex: Stagehand::SessionExtractParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex
+              }
+
+              type vertex =
+                {
+                  location: String,
+                  project: String,
+                  base_url: String,
+                  headers: ::Hash[Symbol, String]
+                }
+
+              class Vertex < Stagehand::Internal::Type::BaseModel
+                attr_accessor location: String
+
+                attr_accessor project: String
+
+                attr_reader base_url: String?
+
+                def base_url=: (String) -> String
+
+                attr_reader headers: ::Hash[Symbol, String]?
+
+                def headers=: (::Hash[Symbol, String]) -> ::Hash[Symbol, String]
+
+                def initialize: (
+                  location: String,
+                  project: String,
+                  ?base_url: String,
+                  ?headers: ::Hash[Symbol, String]
+                ) -> void
+
+                def to_hash: -> {
+                  location: String,
+                  project: String,
+                  base_url: String,
+                  headers: ::Hash[Symbol, String]
+                }
+              end
+            end
+          end
+
+          type generic_model_config_object =
+            {
+              model_name: String,
+              api_key: String,
+              base_url: String,
+              headers: ::Hash[Symbol, String],
+              provider: Stagehand::Models::SessionExtractParams::Options::Model::GenericModelConfigObject::provider
+            }
+
+          class GenericModelConfigObject < Stagehand::Internal::Type::BaseModel
+            attr_accessor model_name: String
+
+            attr_reader api_key: String?
+
+            def api_key=: (String) -> String
+
+            attr_reader base_url: String?
+
+            def base_url=: (String) -> String
+
+            attr_reader headers: ::Hash[Symbol, String]?
+
+            def headers=: (::Hash[Symbol, String]) -> ::Hash[Symbol, String]
+
+            attr_reader provider: Stagehand::Models::SessionExtractParams::Options::Model::GenericModelConfigObject::provider?
+
+            def provider=: (
+              Stagehand::Models::SessionExtractParams::Options::Model::GenericModelConfigObject::provider
+            ) -> Stagehand::Models::SessionExtractParams::Options::Model::GenericModelConfigObject::provider
+
+            def initialize: (
+              model_name: String,
+              ?api_key: String,
+              ?base_url: String,
+              ?headers: ::Hash[Symbol, String],
+              ?provider: Stagehand::Models::SessionExtractParams::Options::Model::GenericModelConfigObject::provider
+            ) -> void
+
+            def to_hash: -> {
+              model_name: String,
+              api_key: String,
+              base_url: String,
+              headers: ::Hash[Symbol, String],
+              provider: Stagehand::Models::SessionExtractParams::Options::Model::GenericModelConfigObject::provider
+            }
+
+            type provider =
+              :openai | :anthropic | :google | :microsoft | :bedrock
+
+            module Provider
+              extend Stagehand::Internal::Type::Enum
+
+              OPENAI: :openai
+              ANTHROPIC: :anthropic
+              GOOGLE: :google
+              MICROSOFT: :microsoft
+              BEDROCK: :bedrock
+
+              def self?.values: -> ::Array[Stagehand::Models::SessionExtractParams::Options::Model::GenericModelConfigObject::provider]
+            end
+          end
+
           def self?.variants: -> ::Array[Stagehand::Models::SessionExtractParams::Options::model]
         end
       end
diff --git a/sig/stagehand/models/session_observe_params.rbs b/sig/stagehand/models/session_observe_params.rbs
index 4aad068..a73966f 100644
--- a/sig/stagehand/models/session_observe_params.rbs
+++ b/sig/stagehand/models/session_observe_params.rbs
@@ -54,6 +54,7 @@ module Stagehand
 
       type options =
         {
+          ignore_selectors: ::Array[String],
           model: Stagehand::Models::SessionObserveParams::Options::model,
           selector: String,
           timeout: Float,
@@ -61,6 +62,10 @@ module Stagehand
         }
 
       class Options < Stagehand::Internal::Type::BaseModel
+        attr_reader ignore_selectors: ::Array[String]?
+
+        def ignore_selectors=: (::Array[String]) -> ::Array[String]
+
         attr_reader model: Stagehand::Models::SessionObserveParams::Options::model?
 
         def model=: (
@@ -82,6 +87,7 @@ module Stagehand
         ) -> ::Hash[Symbol, Stagehand::Models::SessionObserveParams::Options::variable]
 
         def initialize: (
+          ?ignore_selectors: ::Array[String],
           ?model: Stagehand::Models::SessionObserveParams::Options::model,
           ?selector: String,
           ?timeout: Float,
@@ -89,17 +95,341 @@ module Stagehand
         ) -> void
 
         def to_hash: -> {
+          ignore_selectors: ::Array[String],
           model: Stagehand::Models::SessionObserveParams::Options::model,
           selector: String,
           timeout: Float,
           variables: ::Hash[Symbol, Stagehand::Models::SessionObserveParams::Options::variable]
         }
 
-        type model = Stagehand::ModelConfig | String
+        type model =
+          Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject
+          | Stagehand::SessionObserveParams::Options::Model::GenericModelConfigObject
+          | String
 
         module Model
           extend Stagehand::Internal::Type::Union
 
+          type vertex_model_config_object =
+            {
+              auth: Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth,
+              model_name: String,
+              provider: :vertex,
+              provider_options: Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::ProviderOptions,
+              api_key: String,
+              base_url: String,
+              headers: ::Hash[Symbol, String]
+            }
+
+          class VertexModelConfigObject < Stagehand::Internal::Type::BaseModel
+            attr_accessor auth: Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth
+
+            attr_accessor model_name: String
+
+            attr_accessor provider: :vertex
+
+            attr_accessor provider_options: Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::ProviderOptions
+
+            attr_reader api_key: String?
+
+            def api_key=: (String) -> String
+
+            attr_reader base_url: String?
+
+            def base_url=: (String) -> String
+
+            attr_reader headers: ::Hash[Symbol, String]?
+
+            def headers=: (::Hash[Symbol, String]) -> ::Hash[Symbol, String]
+
+            def initialize: (
+              auth: Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth,
+              model_name: String,
+              provider_options: Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::ProviderOptions,
+              ?api_key: String,
+              ?base_url: String,
+              ?headers: ::Hash[Symbol, String],
+              ?provider: :vertex
+            ) -> void
+
+            def to_hash: -> {
+              auth: Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth,
+              model_name: String,
+              provider: :vertex,
+              provider_options: Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::ProviderOptions,
+              api_key: String,
+              base_url: String,
+              headers: ::Hash[Symbol, String]
+            }
+
+            type auth =
+              {
+                credentials: Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials,
+                type: :googleServiceAccount,
+                project_id: String,
+                scopes: Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::scopes,
+                universe_domain: String
+              }
+
+            class Auth < Stagehand::Internal::Type::BaseModel
+              attr_accessor credentials: Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials
+
+              attr_accessor type: :googleServiceAccount
+
+              attr_reader project_id: String?
+
+              def project_id=: (String) -> String
+
+              attr_reader scopes: Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::scopes?
+
+              def scopes=: (
+                Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::scopes
+              ) -> Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::scopes
+
+              attr_reader universe_domain: String?
+
+              def universe_domain=: (String) -> String
+
+              def initialize: (
+                credentials: Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials,
+                ?project_id: String,
+                ?scopes: Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::scopes,
+                ?universe_domain: String,
+                ?type: :googleServiceAccount
+              ) -> void
+
+              def to_hash: -> {
+                credentials: Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials,
+                type: :googleServiceAccount,
+                project_id: String,
+                scopes: Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::scopes,
+                universe_domain: String
+              }
+
+              type credentials =
+                {
+                  client_email: String,
+                  private_key: String,
+                  :auth_provider_x509_cert_url => String,
+                  auth_uri: String,
+                  client_id: String,
+                  :client_x509_cert_url => String,
+                  private_key_id: String,
+                  project_id: String,
+                  token_uri: String,
+                  type: Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials::type_,
+                  universe_domain: String
+                }
+
+              class Credentials < Stagehand::Internal::Type::BaseModel
+                attr_accessor client_email: String
+
+                attr_accessor private_key: String
+
+                attr_reader auth_provider_x509_cert_url: String?
+
+                def auth_provider_x509_cert_url=: (String) -> String
+
+                attr_reader auth_uri: String?
+
+                def auth_uri=: (String) -> String
+
+                attr_reader client_id: String?
+
+                def client_id=: (String) -> String
+
+                attr_reader client_x509_cert_url: String?
+
+                def client_x509_cert_url=: (String) -> String
+
+                attr_reader private_key_id: String?
+
+                def private_key_id=: (String) -> String
+
+                attr_reader project_id: String?
+
+                def project_id=: (String) -> String
+
+                attr_reader token_uri: String?
+
+                def token_uri=: (String) -> String
+
+                attr_reader type: Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials::type_?
+
+                def type=: (
+                  Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials::type_
+                ) -> Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials::type_
+
+                attr_reader universe_domain: String?
+
+                def universe_domain=: (String) -> String
+
+                def initialize: (
+                  client_email: String,
+                  private_key: String,
+                  ?auth_provider_x509_cert_url: String,
+                  ?auth_uri: String,
+                  ?client_id: String,
+                  ?client_x509_cert_url: String,
+                  ?private_key_id: String,
+                  ?project_id: String,
+                  ?token_uri: String,
+                  ?type: Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials::type_,
+                  ?universe_domain: String
+                ) -> void
+
+                def to_hash: -> {
+                  client_email: String,
+                  private_key: String,
+                  :auth_provider_x509_cert_url => String,
+                  auth_uri: String,
+                  client_id: String,
+                  :client_x509_cert_url => String,
+                  private_key_id: String,
+                  project_id: String,
+                  token_uri: String,
+                  type: Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials::type_,
+                  universe_domain: String
+                }
+
+                type type_ = :service_account
+
+                module Type
+                  extend Stagehand::Internal::Type::Enum
+
+                  SERVICE_ACCOUNT: :service_account
+
+                  def self?.values: -> ::Array[Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::Credentials::type_]
+                end
+              end
+
+              type scopes = String | ::Array[String]
+
+              module Scopes
+                extend Stagehand::Internal::Type::Union
+
+                def self?.variants: -> ::Array[Stagehand::Models::SessionObserveParams::Options::Model::VertexModelConfigObject::Auth::scopes]
+
+                StringArray: Stagehand::Internal::Type::Converter
+              end
+            end
+
+            type provider_options =
+              {
+                vertex: Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex
+              }
+
+            class ProviderOptions < Stagehand::Internal::Type::BaseModel
+              attr_accessor vertex: Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex
+
+              def initialize: (
+                vertex: Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex
+              ) -> void
+
+              def to_hash: -> {
+                vertex: Stagehand::SessionObserveParams::Options::Model::VertexModelConfigObject::ProviderOptions::Vertex
+              }
+
+              type vertex =
+                {
+                  location: String,
+                  project: String,
+                  base_url: String,
+                  headers: ::Hash[Symbol, String]
+                }
+
+              class Vertex < Stagehand::Internal::Type::BaseModel
+                attr_accessor location: String
+
+                attr_accessor project: String
+
+                attr_reader base_url: String?
+
+                def base_url=: (String) -> String
+
+                attr_reader headers: ::Hash[Symbol, String]?
+
+                def headers=: (::Hash[Symbol, String]) -> ::Hash[Symbol, String]
+
+                def initialize: (
+                  location: String,
+                  project: String,
+                  ?base_url: String,
+                  ?headers: ::Hash[Symbol, String]
+                ) -> void
+
+                def to_hash: -> {
+                  location: String,
+                  project: String,
+                  base_url: String,
+                  headers: ::Hash[Symbol, String]
+                }
+              end
+            end
+          end
+
+          type generic_model_config_object =
+            {
+              model_name: String,
+              api_key: String,
+              base_url: String,
+              headers: ::Hash[Symbol, String],
+              provider: Stagehand::Models::SessionObserveParams::Options::Model::GenericModelConfigObject::provider
+            }
+
+          class GenericModelConfigObject < Stagehand::Internal::Type::BaseModel
+            attr_accessor model_name: String
+
+            attr_reader api_key: String?
+
+            def api_key=: (String) -> String
+
+            attr_reader base_url: String?
+
+            def base_url=: (String) -> String
+
+            attr_reader headers: ::Hash[Symbol, String]?
+
+            def headers=: (::Hash[Symbol, String]) -> ::Hash[Symbol, String]
+
+            attr_reader provider: Stagehand::Models::SessionObserveParams::Options::Model::GenericModelConfigObject::provider?
+
+            def provider=: (
+              Stagehand::Models::SessionObserveParams::Options::Model::GenericModelConfigObject::provider
+            ) -> Stagehand::Models::SessionObserveParams::Options::Model::GenericModelConfigObject::provider
+
+            def initialize: (
+              model_name: String,
+              ?api_key: String,
+              ?base_url: String,
+              ?headers: ::Hash[Symbol, String],
+              ?provider: Stagehand::Models::SessionObserveParams::Options::Model::GenericModelConfigObject::provider
+            ) -> void
+
+            def to_hash: -> {
+              model_name: String,
+              api_key: String,
+              base_url: String,
+              headers: ::Hash[Symbol, String],
+              provider: Stagehand::Models::SessionObserveParams::Options::Model::GenericModelConfigObject::provider
+            }
+
+            type provider =
+              :openai | :anthropic | :google | :microsoft | :bedrock
+
+            module Provider
+              extend Stagehand::Internal::Type::Enum
+
+              OPENAI: :openai
+              ANTHROPIC: :anthropic
+              GOOGLE: :google
+              MICROSOFT: :microsoft
+              BEDROCK: :bedrock
+
+              def self?.values: -> ::Array[Stagehand::Models::SessionObserveParams::Options::Model::GenericModelConfigObject::provider]
+            end
+          end
+
           def self?.variants: -> ::Array[Stagehand::Models::SessionObserveParams::Options::model]
         end
 
diff --git a/test/stagehand/client_test.rb b/test/stagehand/client_test.rb
index 4b96ac0..dc061f1 100644
--- a/test/stagehand/client_test.rb
+++ b/test/stagehand/client_test.rb
@@ -356,8 +356,8 @@ def test_client_redirect_307
       assert_equal(recorded.method, _1.method)
       assert_equal(recorded.body, _1.body)
       assert_equal(
-        recorded.headers.transform_keys(&:downcase).fetch("content-type"),
-        _1.headers.transform_keys(&:downcase).fetch("content-type")
+        recorded.headers.transform_keys(&:downcase)["content-type"],
+        _1.headers.transform_keys(&:downcase)["content-type"]
       )
     end
   end
@@ -474,8 +474,9 @@ def test_default_headers
     stagehand.sessions.start(model_name: "openai/gpt-5.4-mini")
 
     assert_requested(:any, /./) do |req|
-      headers = req.headers.transform_keys(&:downcase).fetch_values("accept", "content-type")
-      headers.each { refute_empty(_1) }
+      headers = req.headers.transform_keys(&:downcase)
+      expected = req.body.nil? ? ["accept"] : %w[accept content-type]
+      headers.fetch_values(*expected).each { refute_empty(_1) }
     end
   end
 end