diff --git a/js/plugins/middleware/.npmignore b/js/plugins/middleware/.npmignore
new file mode 100644
index 0000000000..5ea8bc610d
--- /dev/null
+++ b/js/plugins/middleware/.npmignore
@@ -0,0 +1,3 @@
+node_modules
+tsconfig.json
+tsup.config.ts
\ No newline at end of file
diff --git a/js/plugins/middleware/LICENSE b/js/plugins/middleware/LICENSE
new file mode 100644
index 0000000000..26a870243c
--- /dev/null
+++ b/js/plugins/middleware/LICENSE
@@ -0,0 +1,203 @@
+
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+
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+      by You to the Licensor shall be under the terms and conditions of
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+   Unless required by applicable law or agreed to in writing, software
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\ No newline at end of file
diff --git a/js/plugins/middleware/README.md b/js/plugins/middleware/README.md
new file mode 100644
index 0000000000..bd07280cda
--- /dev/null
+++ b/js/plugins/middleware/README.md
@@ -0,0 +1,3 @@
+# Genkit Middleware
+
+This package provides middleware for Genkit.
diff --git a/js/plugins/middleware/examples/fallback.ts b/js/plugins/middleware/examples/fallback.ts
new file mode 100644
index 0000000000..27899fce44
--- /dev/null
+++ b/js/plugins/middleware/examples/fallback.ts
@@ -0,0 +1,42 @@
+/**
+ * Copyright 2026 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { googleAI } from '@genkit-ai/google-genai';
+import { genkit } from 'genkit';
+import { fallback } from '../src/index.js';
+
+const ai = genkit({
+  plugins: [googleAI()],
+});
+
+async function main() {
+  const { text } = await ai.generate({
+    model: googleAI.model('gemini-3-pro-preview'),
+    prompt: 'Tell me a joke about fallbacks.',
+    use: [
+      fallback({
+        models: [googleAI.model('gemini-3-flash-preview')],
+        statuses: ['RESOURCE_EXHAUSTED', 'UNAVAILABLE', 'DEADLINE_EXCEEDED'],
+        onError: (err) => {
+          console.error(`Fallback triggered due to error: ${err.message}`);
+        },
+      }),
+    ],
+  });
+  console.log(text);
+}
+
+main().catch(console.error);
diff --git a/js/plugins/middleware/examples/filesystem.ts b/js/plugins/middleware/examples/filesystem.ts
new file mode 100644
index 0000000000..8f234db147
--- /dev/null
+++ b/js/plugins/middleware/examples/filesystem.ts
@@ -0,0 +1,40 @@
+/**
+ * Copyright 2026 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { googleAI } from '@genkit-ai/google-genai';
+import { genkit } from 'genkit';
+import { filesystem } from '../src/index.js';
+
+const ai = genkit({
+  plugins: [googleAI()],
+});
+
+async function main() {
+  const { text } = await ai.generate({
+    model: googleAI.model('gemini-3-flash-preview'),
+    prompt:
+      'Can you list the files in my temporary directory and read whatever is in `hello.txt`?',
+    use: [
+      filesystem({
+        rootDirectory: process.env.TEMP_DIR || '/tmp',
+      }),
+    ],
+    maxTurns: 10,
+  });
+  console.log(text);
+}
+
+main().catch(console.error);
diff --git a/js/plugins/middleware/examples/retry.ts b/js/plugins/middleware/examples/retry.ts
new file mode 100644
index 0000000000..44c46475eb
--- /dev/null
+++ b/js/plugins/middleware/examples/retry.ts
@@ -0,0 +1,42 @@
+/**
+ * Copyright 2026 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { googleAI } from '@genkit-ai/google-genai';
+import { genkit } from 'genkit';
+import { retry } from '../src/index.js'; // @genkit-ai/middleware
+
+const ai = genkit({
+  plugins: [googleAI()],
+});
+
+async function main() {
+  const { text } = await ai.generate({
+    model: googleAI.model('gemini-3-pro-preview'),
+    prompt: 'Tell me a joke about retries.',
+    use: [
+      retry({
+        maxRetries: 3,
+        initialDelayMs: 500,
+        onError: (err, attempt) => {
+          console.error(`Retry attempt ${attempt} failed: ${err.message}`);
+        },
+      }),
+    ],
+  });
+  console.log(text);
+}
+
+main().catch(console.error);
diff --git a/js/plugins/middleware/package.json b/js/plugins/middleware/package.json
new file mode 100644
index 0000000000..059f38ebd7
--- /dev/null
+++ b/js/plugins/middleware/package.json
@@ -0,0 +1,55 @@
+{
+  "name": "@genkit-ai/middleware",
+  "description": "Middleware for Genkit",
+  "keywords": [
+    "genkit",
+    "genkit-plugin",
+    "google cloud",
+    "google ai",
+    "ai",
+    "genai",
+    "generative-ai"
+  ],
+  "version": "1.28.0",
+  "type": "commonjs",
+  "scripts": {
+    "check": "tsc",
+    "compile": "tsup-node",
+    "build:clean": "rimraf ./lib",
+    "build": "npm-run-all build:clean check compile",
+    "build:watch": "tsup-node --watch",
+    "test": "tsx --test tests/**/*.ts"
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/firebase/genkit.git",
+    "directory": "js/plugins/middleware"
+  },
+  "author": "genkit",
+  "license": "Apache-2.0",
+  "peerDependencies": {
+    "genkit": "workspace:^"
+  },
+  "devDependencies": {
+    "@genkit-ai/google-genai": "workspace:^",
+    "@types/mime-types": "^3.0.1",
+    "@types/node": "^20.11.16",
+    "npm-run-all": "^4.1.5",
+    "rimraf": "^6.0.1",
+    "tsup": "^8.0.2",
+    "tsx": "^4.7.0",
+    "typescript": "^4.9.0"
+  },
+  "types": "./lib/index.d.ts",
+  "exports": {
+    ".": {
+      "types": "./lib/index.d.ts",
+      "import": "./lib/index.mjs",
+      "require": "./lib/index.js",
+      "default": "./lib/index.js"
+    }
+  },
+  "dependencies": {
+    "mime-types": "^3.0.2"
+  }
+}
diff --git a/js/plugins/middleware/src/fallback.ts b/js/plugins/middleware/src/fallback.ts
new file mode 100644
index 0000000000..a5ae7ff9a5
--- /dev/null
+++ b/js/plugins/middleware/src/fallback.ts
@@ -0,0 +1,141 @@
+/**
+ * Copyright 2026 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import {
+  GenkitError,
+  ModelReferenceSchema,
+  generateMiddleware,
+  z,
+  type GenerateMiddleware,
+  type StatusName,
+} from 'genkit';
+import { ModelAction } from 'genkit/model';
+import { Registry } from 'genkit/registry';
+
+const DEFAULT_FALLBACK_STATUSES: StatusName[] = [
+  'UNAVAILABLE',
+  'DEADLINE_EXCEEDED',
+  'RESOURCE_EXHAUSTED',
+  'ABORTED',
+  'INTERNAL',
+  'NOT_FOUND',
+  'UNIMPLEMENTED',
+];
+
+export const FallbackOptionsSchema = z
+  .object({
+    /**
+     * An array of models to try in order.
+     */
+    models: z.array(z.union([z.string(), ModelReferenceSchema])),
+    /**
+     * An array of `StatusName` values that should trigger a fallback.
+     * @default ['UNAVAILABLE', 'DEADLINE_EXCEEDED', 'RESOURCE_EXHAUSTED', 'ABORTED', 'INTERNAL', 'NOT_FOUND', 'UNIMPLEMENTED']
+     */
+    statuses: z.array(z.string()).optional(),
+  })
+  .passthrough();
+
+export interface FallbackOptions extends z.infer<typeof FallbackOptionsSchema> {
+  /**
+   * A callback to be executed on each fallback attempt.
+   */
+  onError?: (error: Error) => void;
+}
+
+/**
+ * Creates a middleware that falls back to a different model on specific error statuses.
+ *
+ * ```ts
+ * const { text } = await ai.generate({
+ *   model: googleAI.model('gemini-2.5-pro'),
+ *   prompt: 'You are a helpful AI assistant named Walt, say hello',
+ *   use: [
+ *     fallback({
+ *       models: [googleAI.model('gemini-2.5-flash')],
+ *       statuses: ['RESOURCE_EXHAUSTED'],
+ *     }),
+ *   ],
+ * });
+ * ```
+ */
+export const fallback: GenerateMiddleware<typeof FallbackOptionsSchema> =
+  generateMiddleware(
+    {
+      name: 'fallback',
+      configSchema: FallbackOptionsSchema,
+    },
+    (options: FallbackOptions | undefined, ai) => {
+      const {
+        models = [],
+        statuses = DEFAULT_FALLBACK_STATUSES,
+        onError,
+      } = options || {};
+
+      return {
+        model: async (req, ctx, next) => {
+          try {
+            return await next(req, ctx);
+          } catch (e) {
+            if (
+              e instanceof GenkitError &&
+              statuses.includes(e.status as StatusName)
+            ) {
+              onError?.(e);
+              let lastError: any = e;
+              for (const model of models) {
+                const normalizedModel = await resolveModel(ai.registry, model);
+                try {
+                  return await normalizedModel.model(
+                    {
+                      ...req,
+                      config: normalizedModel.config ?? req.config,
+                    },
+                    ctx
+                  );
+                } catch (e2) {
+                  lastError = e2;
+                  if (
+                    e2 instanceof GenkitError &&
+                    statuses.includes(e2.status as StatusName)
+                  ) {
+                    onError?.(e2);
+                    continue;
+                  }
+                  throw e2;
+                }
+              }
+              throw lastError;
+            }
+            throw e;
+          }
+        },
+      };
+    }
+  );
+
+async function resolveModel(
+  registry: Registry,
+  model: string | z.infer<typeof ModelReferenceSchema>
+): Promise<{ model: ModelAction; config?: any }> {
+  if (typeof model === 'string') {
+    return { model: await registry.lookupAction(`/model/${model}`) };
+  }
+  return {
+    model: await registry.lookupAction(`/model/${model.name}`),
+    config: model.config,
+  };
+}
diff --git a/js/plugins/middleware/src/filesystem.ts b/js/plugins/middleware/src/filesystem.ts
new file mode 100644
index 0000000000..8a8fdc141c
--- /dev/null
+++ b/js/plugins/middleware/src/filesystem.ts
@@ -0,0 +1,119 @@
+/**
+ * Copyright 2026 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import {
+  generateMiddleware,
+  MessageData,
+  z,
+  type GenerateMiddleware,
+} from 'genkit';
+import * as path from 'path';
+import { defineListFileTool } from './filesystem/list_files';
+import { defineReadFileTool } from './filesystem/read_file';
+import { defineSearchAndReplaceTool } from './filesystem/search_and_replace';
+import { defineWriteFileTool } from './filesystem/write_file';
+
+export const FilesystemOptionsSchema = z.object({
+  rootDirectory: z
+    .string()
+    .describe(
+      'The root directory to which all filesystem operations are restricted.'
+    ),
+});
+
+export type FilesystemOptions = z.infer<typeof FilesystemOptionsSchema>;
+
+/**
+ * Creates a middleware that grants the LLM access to the filesystem.
+ * Injects `list_files`, `read_file`, `write_file`, and `search_and_replace` tools restricted to the provided `rootDirectory`.
+ */
+export const filesystem: GenerateMiddleware<typeof FilesystemOptionsSchema> =
+  generateMiddleware(
+    {
+      name: 'filesystem',
+      configSchema: FilesystemOptionsSchema,
+    },
+    (options) => {
+      if (!options?.rootDirectory) {
+        throw new Error(
+          'filesystem middleware requires a rootDirectory option'
+        );
+      }
+      const rootDir = path.resolve(options.rootDirectory);
+
+      function resolvePath(requestedPath: string) {
+        const p = path.resolve(rootDir, requestedPath);
+        // Ensure the resolved path starts with the rootDir and a path separator
+        // to prevent directory traversal attacks (e.g. rootDir is /a/b, requested is ../b_secret)
+        if (!p.startsWith(rootDir + path.sep) && p !== rootDir) {
+          throw new Error('Access denied: Path is outside of root directory.');
+        }
+        return p;
+      }
+
+      const messageQueue: MessageData[] = [];
+
+      const listFilesTool = defineListFileTool(resolvePath);
+      const readFileTool = defineReadFileTool(messageQueue, resolvePath);
+      const writeFileTool = defineWriteFileTool(resolvePath);
+      const searchAndReplaceTool = defineSearchAndReplaceTool(resolvePath);
+
+      const filesystemTools = [
+        listFilesTool,
+        readFileTool,
+        writeFileTool,
+        searchAndReplaceTool,
+      ];
+      const filesystemToolNames = filesystemTools.map((t) => t.__action.name);
+
+      return {
+        tools: filesystemTools,
+        tool: async (req, ctx, next) => {
+          try {
+            return await next(req, ctx);
+          } catch (e: any) {
+            if (filesystemToolNames.includes(req.toolRequest.name)) {
+              const errorPart = {
+                text: `Tool '${req.toolRequest.name}' failed: ${
+                  e.message || String(e)
+                }`,
+              };
+              if (
+                messageQueue.length > 0 &&
+                messageQueue[messageQueue.length - 1].role === 'user'
+              ) {
+                messageQueue[messageQueue.length - 1].content.push(errorPart);
+              } else {
+                messageQueue.push({
+                  role: 'user',
+                  content: [errorPart],
+                });
+              }
+              return;
+            }
+            throw e;
+          }
+        },
+        generate: async (req, ctx, next) => {
+          if (messageQueue.length > 0) {
+            req.messages.push(...messageQueue);
+            messageQueue.length = 0;
+          }
+          return await next(req, ctx);
+        },
+      };
+    }
+  );
diff --git a/js/plugins/middleware/src/filesystem/list_files.ts b/js/plugins/middleware/src/filesystem/list_files.ts
new file mode 100644
index 0000000000..9ea1376406
--- /dev/null
+++ b/js/plugins/middleware/src/filesystem/list_files.ts
@@ -0,0 +1,70 @@
+/**
+ * Copyright 2026 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import * as fs from 'fs/promises';
+import { ToolAction, z } from 'genkit';
+import { tool } from 'genkit/beta';
+import * as path from 'path';
+
+export function defineListFileTool(
+  resolvePath: (requestedPath: string) => string
+): ToolAction {
+  return tool(
+    {
+      name: 'list_files',
+      description:
+        'Lists files and directories in a given path. Returns a list of objects with path and type.',
+      inputSchema: z.object({
+        dirPath: z
+          .string()
+          .describe('Directory path relative to root.')
+          .default(''),
+        recursive: z
+          .boolean()
+          .describe('Whether to list files recursively.')
+          .default(false),
+      }),
+      outputSchema: z.array(
+        z.object({ path: z.string(), isDirectory: z.boolean() })
+      ),
+    },
+    async (input) => {
+      const targetDir = resolvePath(input.dirPath);
+
+      async function list(dir: string, recursive: boolean, base: string = '') {
+        const results: { path: string; isDirectory: boolean }[] = [];
+        const entries = await fs.readdir(dir, { withFileTypes: true });
+        for (const entry of entries) {
+          const relativePath = path.join(base, entry.name);
+          results.push({
+            path: relativePath,
+            isDirectory: entry.isDirectory(),
+          });
+          if (entry.isDirectory() && recursive) {
+            const subResults = await list(
+              path.join(dir, entry.name),
+              true,
+              relativePath
+            );
+            results.push(...subResults);
+          }
+        }
+        return results;
+      }
+      return await list(targetDir, input.recursive);
+    }
+  );
+}
diff --git a/js/plugins/middleware/src/filesystem/read_file.ts b/js/plugins/middleware/src/filesystem/read_file.ts
new file mode 100644
index 0000000000..4bef98ac2d
--- /dev/null
+++ b/js/plugins/middleware/src/filesystem/read_file.ts
@@ -0,0 +1,76 @@
+/**
+ * Copyright 2026 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import * as fs from 'fs/promises';
+import { MessageData, Part, ToolAction, z } from 'genkit';
+import { tool } from 'genkit/beta';
+import * as mime from 'mime-types';
+import * as path from 'path';
+
+export function defineReadFileTool(
+  messageQueue: MessageData[],
+  resolvePath: (requestedPath: string) => string
+): ToolAction {
+  return tool(
+    {
+      name: 'read_file',
+      description: 'Reads the contents of a file',
+      inputSchema: z.object({
+        filePath: z.string().describe('File path relative to root.'),
+      }),
+      outputSchema: z.string(),
+    },
+    async (input) => {
+      const targetFile = resolvePath(input.filePath);
+      const ext = path.extname(targetFile).toLowerCase();
+      const mimeType = mime.lookup(ext);
+      const isImage = mimeType != false && mimeType?.startsWith('image/');
+
+      const parts: Part[] = [];
+
+      if (isImage && mimeType) {
+        const buffer = await fs.readFile(targetFile);
+        const base64 = buffer.toString('base64');
+
+        parts.push({
+          text: `\n\nread_file result ${mimeType} ${input.filePath}`,
+        });
+        parts.push({
+          media: {
+            url: `data:${mimeType};base64,${base64}`,
+            contentType: mimeType,
+          },
+        });
+      } else {
+        const content = await fs.readFile(targetFile, 'utf8');
+        parts.push({
+          text: `<read_file path="${input.filePath}">\n${content}\n</read_file>`,
+        });
+      }
+
+      if (
+        messageQueue.length > 0 &&
+        messageQueue[messageQueue.length - 1].role === 'user'
+      ) {
+        messageQueue[messageQueue.length - 1].content.push(...parts);
+      } else {
+        messageQueue.push({ role: 'user', content: parts });
+      }
+
+      return `File ${input.filePath} read successfully, see contents below`;
+    }
+  );
+}
diff --git a/js/plugins/middleware/src/filesystem/search_and_replace.ts b/js/plugins/middleware/src/filesystem/search_and_replace.ts
new file mode 100644
index 0000000000..a64eb826a6
--- /dev/null
+++ b/js/plugins/middleware/src/filesystem/search_and_replace.ts
@@ -0,0 +1,119 @@
+/**
+ * Copyright 2026 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import * as fs from 'fs/promises';
+import { ToolAction, z } from 'genkit';
+import { tool } from 'genkit/beta';
+
+export function defineSearchAndReplaceTool(
+  resolvePath: (requestedPath: string) => string
+): ToolAction {
+  return tool(
+    {
+      name: 'search_and_replace',
+      description: 'Replaces text in a file using search and replace blocks. ',
+      inputSchema: z.object({
+        filePath: z.string().describe('File path relative to root.'),
+        edits: z.array(
+          z
+            .string()
+            .describe(
+              'A search and replace block string in the format:\n' +
+                '<<<<<<< SEARCH\n[search content]\n=======\n[replace content]\n>>>>>>> REPLACE'
+            )
+        ),
+      }),
+      outputSchema: z.string(),
+    },
+    async (input) => {
+      const targetFile = resolvePath(input.filePath);
+      let content = await fs.readFile(targetFile, 'utf8');
+
+      for (const editBlock of input.edits) {
+        const startMarker = '<<<<<<< SEARCH\n';
+        const endMarker = '\n>>>>>>> REPLACE';
+        const separator = '\n=======\n';
+
+        if (
+          !editBlock.startsWith(startMarker) ||
+          !editBlock.endsWith(endMarker)
+        ) {
+          throw new Error(
+            'Invalid edit block format. Block must start with "<<<<<<< SEARCH\\n" and end with "\\n>>>>>>> REPLACE"'
+          );
+        }
+
+        const innerContent = editBlock.substring(
+          startMarker.length,
+          editBlock.length - endMarker.length
+        );
+
+        // Find all possible separator positions
+        const separatorIndices: number[] = [];
+        let pos = innerContent.indexOf(separator);
+        while (pos !== -1) {
+          separatorIndices.push(pos);
+          pos = innerContent.indexOf(separator, pos + 1);
+        }
+
+        if (separatorIndices.length === 0) {
+          throw new Error(
+            'Invalid edit block format. Missing separator "\\n=======\\n"'
+          );
+        }
+
+        // Try to find a split that matches the content
+        let match: { search: string; replace: string } | null = null;
+        let matchCount = 0;
+
+        for (const splitIndex of separatorIndices) {
+          const search = innerContent.substring(0, splitIndex);
+          const replace = innerContent.substring(splitIndex + separator.length);
+
+          if (content.includes(search)) {
+            // If we already have a match, only replace it if this one is longer (more specific)
+            if (!match || search.length > match.search.length) {
+              match = { search, replace };
+            }
+            matchCount++;
+          }
+        }
+
+        if (matchCount === 0) {
+          throw new Error(
+            `Search content not found in file ${input.filePath}. ` +
+              `Make sure the search block matches the file content exactly, ` +
+              `including whitespace and indentation.`
+          );
+        }
+
+        if (matchCount > 1) {
+          // If multiple splits match, prefer the one with the longest search string.
+          // This assumes that a longer match is more specific and likely what the user intended
+          // if they included markers in their search block.
+        }
+
+        // Apply the replacement (first occurrence only)
+        if (match) {
+          content = content.replace(match.search, match.replace);
+        }
+      }
+
+      await fs.writeFile(targetFile, content, 'utf8');
+      return `Successfully applied ${input.edits.length} edit(s) to ${input.filePath}.`;
+    }
+  );
+}
diff --git a/js/plugins/middleware/src/filesystem/write_file.ts b/js/plugins/middleware/src/filesystem/write_file.ts
new file mode 100644
index 0000000000..886467a8b4
--- /dev/null
+++ b/js/plugins/middleware/src/filesystem/write_file.ts
@@ -0,0 +1,42 @@
+/**
+ * Copyright 2026 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import * as fs from 'fs/promises';
+import { ToolAction, z } from 'genkit';
+import { tool } from 'genkit/beta';
+import * as path from 'path';
+
+export function defineWriteFileTool(
+  resolvePath: (requestedPath: string) => string
+): ToolAction {
+  return tool(
+    {
+      name: 'write_file',
+      description: 'Writes content to a file, overwriting it if it exists.',
+      inputSchema: z.object({
+        filePath: z.string().describe('File path relative to root.'),
+        content: z.string().describe('Content to write to the file.'),
+      }),
+      outputSchema: z.string(),
+    },
+    async (input) => {
+      const targetFile = resolvePath(input.filePath);
+      await fs.mkdir(path.dirname(targetFile), { recursive: true });
+      await fs.writeFile(targetFile, input.content, 'utf8');
+      return `File ${input.filePath} written successfully.`;
+    }
+  );
+}
diff --git a/js/plugins/middleware/src/index.ts b/js/plugins/middleware/src/index.ts
new file mode 100644
index 0000000000..6dbbaac587
--- /dev/null
+++ b/js/plugins/middleware/src/index.ts
@@ -0,0 +1,19 @@
+/**
+ * Copyright 2026 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+export { fallback } from './fallback.js';
+export { filesystem } from './filesystem.js';
+export { retry } from './retry.js';
diff --git a/js/plugins/middleware/src/retry.ts b/js/plugins/middleware/src/retry.ts
new file mode 100644
index 0000000000..161fbf835f
--- /dev/null
+++ b/js/plugins/middleware/src/retry.ts
@@ -0,0 +1,169 @@
+/**
+ * Copyright 2026 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import {
+  GenkitError,
+  generateMiddleware,
+  z,
+  type GenerateMiddleware,
+  type StatusName,
+} from 'genkit';
+
+export const RetryOptionsSchema = z
+  .object({
+    /**
+     * The maximum number of times to retry a failed request.
+     * @default 3
+     */
+    maxRetries: z.number().optional(),
+    /**
+     * An array of `StatusName` values that should trigger a retry.
+     * @default ['UNAVAILABLE', 'DEADLINE_EXCEEDED', 'RESOURCE_EXHAUSTED', 'ABORTED', 'INTERNAL']
+     */
+    statuses: z.array(z.string()).optional(),
+    /**
+     * The initial delay between retries, in milliseconds.
+     * @default 1000
+     */
+    initialDelayMs: z.number().optional(),
+    /**
+     * The maximum delay between retries, in milliseconds.
+     * @default 60000
+     */
+    maxDelayMs: z.number().optional(),
+    /**
+     * The factor by which the delay increases after each retry (exponential backoff).
+     * @default 2
+     */
+    backoffFactor: z.number().optional(),
+    /**
+     * Whether to disable jitter on the delay. Jitter adds a random factor to the
+     * delay to help prevent a "thundering herd" of clients all retrying at the
+     * same time.
+     * @default false
+     */
+    noJitter: z.boolean().optional(),
+  })
+  .passthrough();
+
+export interface RetryOptions extends z.infer<typeof RetryOptionsSchema> {
+  /**
+   * A callback to be executed on each retry attempt.
+   */
+  onError?: (error: Error, attempt: number) => void;
+}
+
+const DEFAULT_RETRY_STATUSES: StatusName[] = [
+  'UNAVAILABLE',
+  'DEADLINE_EXCEEDED',
+  'RESOURCE_EXHAUSTED',
+  'ABORTED',
+  'INTERNAL',
+];
+
+let __setTimeout: (
+  callback: (...args: any[]) => void,
+  ms?: number
+) => NodeJS.Timeout = setTimeout;
+
+/**
+ * FOR TESTING ONLY.
+ * @internal
+ */
+export const TEST_ONLY = {
+  setRetryTimeout(
+    impl: (callback: (...args: any[]) => void, ms?: number) => NodeJS.Timeout
+  ) {
+    __setTimeout = impl;
+  },
+};
+
+/**
+ * Creates a middleware that retries requests on specific error statuses.
+ *
+ * ```ts
+ * const { text } = await ai.generate({
+ *   model: googleAI.model('gemini-2.5-pro'),
+ *   prompt: 'You are a helpful AI assistant named Walt, say hello',
+ *   use: [
+ *     retry({
+ *       maxRetries: 2,
+ *       initialDelayMs: 1000,
+ *       backoffFactor: 2,
+ *     }),
+ *   ],
+ * });
+ * ```
+ */
+export const retry: GenerateMiddleware<typeof RetryOptionsSchema> =
+  generateMiddleware(
+    {
+      name: 'retry',
+      configSchema: RetryOptionsSchema,
+    },
+    (options?: RetryOptions) => {
+      const {
+        maxRetries = 3,
+        statuses = DEFAULT_RETRY_STATUSES,
+        initialDelayMs = 1000,
+        maxDelayMs = 60000,
+        backoffFactor = 2,
+        noJitter = false,
+        onError,
+      } = options || {};
+
+      return {
+        model: async (req, ctx, next) => {
+          let lastError: any;
+          let currentDelay = initialDelayMs;
+          for (let i = 0; i <= maxRetries; i++) {
+            try {
+              return await next(req, ctx);
+            } catch (e) {
+              lastError = e;
+              const error = e as Error;
+              if (i < maxRetries) {
+                let shouldRetry = false;
+                if (error instanceof GenkitError) {
+                  if ((statuses as string[]).includes(error.status)) {
+                    shouldRetry = true;
+                  }
+                } else {
+                  shouldRetry = true;
+                }
+
+                if (shouldRetry) {
+                  onError?.(error, i + 1);
+                  let delay = currentDelay;
+                  if (!noJitter) {
+                    delay = delay + 1000 * Math.pow(2, i) * Math.random();
+                  }
+                  await new Promise((resolve) => __setTimeout(resolve, delay));
+                  currentDelay = Math.min(
+                    currentDelay * backoffFactor,
+                    maxDelayMs
+                  );
+                  continue;
+                }
+              }
+              throw error;
+            }
+          }
+          throw lastError;
+        },
+      };
+    }
+  );
diff --git a/js/plugins/middleware/tests/fallback_test.ts b/js/plugins/middleware/tests/fallback_test.ts
new file mode 100644
index 0000000000..009ad53d16
--- /dev/null
+++ b/js/plugins/middleware/tests/fallback_test.ts
@@ -0,0 +1,193 @@
+/**
+ * Copyright 2026 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import * as assert from 'assert';
+import { GenkitError, genkit } from 'genkit';
+import { describe, it } from 'node:test';
+import { fallback } from '../src/fallback.js';
+
+describe('fallback', () => {
+  it('should not fallback on success', async () => {
+    let requestCount = 0;
+    const ai = genkit({});
+    const pm = ai.defineModel({ name: 'programmableModel' }, async (req) => {
+      requestCount++;
+      return { message: { role: 'model', content: [{ text: 'success' }] } };
+    });
+
+    let pmFallbackRequestCount = 0;
+    const pmFallback = ai.defineModel(
+      { name: 'programmableModelFallback' },
+      async (req) => {
+        pmFallbackRequestCount++;
+        return {
+          message: { role: 'model', content: [{ text: 'fallback success' }] },
+        };
+      }
+    );
+
+    const result = await ai.generate({
+      model: pm,
+      prompt: 'test',
+      use: [fallback({ models: [pmFallback] })],
+    });
+
+    assert.strictEqual(requestCount, 1);
+    assert.strictEqual(pmFallbackRequestCount, 0);
+    assert.strictEqual(result.text, 'success');
+  });
+
+  it('should call onError callback', async () => {
+    let requestCount = 0;
+    const ai = genkit({});
+    const pm = ai.defineModel({ name: 'programmableModel' }, async (req) => {
+      requestCount++;
+      throw new GenkitError({ status: 'UNAVAILABLE', message: 'test' });
+    });
+
+    let pmFallbackRequestCount = 0;
+    ai.defineModel({ name: 'programmableModelFallback' }, async (req) => {
+      pmFallbackRequestCount++;
+      throw new GenkitError({
+        status: 'RESOURCE_EXHAUSTED',
+        message: 'test2',
+      });
+    });
+
+    let errorCount = 0;
+    let lastError: Error | undefined;
+
+    await assert.rejects(
+      ai.generate({
+        model: pm,
+        prompt: 'test',
+        use: [
+          fallback({
+            models: ['programmableModelFallback'],
+            onError: (err) => {
+              errorCount++;
+              lastError = err;
+            },
+          }),
+        ],
+      }),
+      /RESOURCE_EXHAUSTED: test2/
+    );
+
+    assert.strictEqual(requestCount, 1);
+    assert.strictEqual(pmFallbackRequestCount, 1);
+    assert.strictEqual(errorCount, 2);
+    assert.ok(lastError);
+    assert.strictEqual(lastError!.message, 'RESOURCE_EXHAUSTED: test2');
+  });
+
+  it('should fallback on a fallbackable error', async () => {
+    let requestCount = 0;
+    const ai = genkit({});
+    const pm = ai.defineModel({ name: 'programmableModel' }, async (req) => {
+      requestCount++;
+      throw new GenkitError({ status: 'RESOURCE_EXHAUSTED', message: 'test' });
+    });
+
+    let pmFallbackRequestCount = 0;
+    ai.defineModel({ name: 'programmableModelFallback' }, async (req) => {
+      pmFallbackRequestCount++;
+      return {
+        message: { role: 'model', content: [{ text: 'fallback success' }] },
+      };
+    });
+
+    const result = await ai.generate({
+      model: pm,
+      prompt: 'test',
+      use: [
+        fallback({
+          models: ['programmableModelFallback'],
+          statuses: ['RESOURCE_EXHAUSTED'],
+        }),
+      ],
+    });
+
+    assert.strictEqual(requestCount, 1);
+    assert.strictEqual(pmFallbackRequestCount, 1);
+    assert.strictEqual(result.text, 'fallback success');
+  });
+
+  it('should throw after all fallbacks fail', async () => {
+    let requestCount = 0;
+    const ai = genkit({});
+    const pm = ai.defineModel({ name: 'programmableModel' }, async (req) => {
+      requestCount++;
+      throw new GenkitError({ status: 'UNAVAILABLE', message: 'test' });
+    });
+
+    let pmFallbackRequestCount = 0;
+    ai.defineModel({ name: 'programmableModelFallback' }, async (req) => {
+      pmFallbackRequestCount++;
+      throw new GenkitError({ status: 'UNAVAILABLE', message: 'test2' });
+    });
+
+    await assert.rejects(
+      ai.generate({
+        model: pm,
+        prompt: 'test',
+        use: [
+          fallback({
+            models: ['programmableModelFallback'],
+          }),
+        ],
+      }),
+      /UNAVAILABLE: test2/
+    );
+
+    assert.strictEqual(requestCount, 1);
+    assert.strictEqual(pmFallbackRequestCount, 1);
+  });
+
+  it('should not fallback on non-fallbackable error', async () => {
+    let requestCount = 0;
+    const ai = genkit({});
+    const pm = ai.defineModel({ name: 'programmableModel' }, async (req) => {
+      requestCount++;
+      throw new GenkitError({ status: 'INVALID_ARGUMENT', message: 'test' });
+    });
+
+    let pmFallbackRequestCount = 0;
+    ai.defineModel({ name: 'programmableModelFallback' }, async (req) => {
+      pmFallbackRequestCount++;
+      return {
+        message: { role: 'model', content: [{ text: 'fallback success' }] },
+      };
+    });
+
+    await assert.rejects(
+      ai.generate({
+        model: pm,
+        prompt: 'test',
+        use: [
+          fallback({
+            models: ['programmableModelFallback'],
+            statuses: ['RESOURCE_EXHAUSTED'],
+          }),
+        ],
+      }),
+      /INVALID_ARGUMENT: test/
+    );
+
+    assert.strictEqual(requestCount, 1);
+    assert.strictEqual(pmFallbackRequestCount, 0);
+  });
+});
diff --git a/js/plugins/middleware/tests/filesystem_image_test.ts b/js/plugins/middleware/tests/filesystem_image_test.ts
new file mode 100644
index 0000000000..d887945d1e
--- /dev/null
+++ b/js/plugins/middleware/tests/filesystem_image_test.ts
@@ -0,0 +1,101 @@
+/**
+ * Copyright 2026 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import * as assert from 'assert';
+import * as fs from 'fs/promises';
+import { genkit } from 'genkit';
+import { afterEach, beforeEach, describe, it } from 'node:test';
+import * as os from 'os';
+import * as path from 'path';
+import { filesystem } from '../src/filesystem.js';
+
+describe('filesystem middleware image support', () => {
+  let tempDir: string;
+
+  beforeEach(async () => {
+    tempDir = await fs.mkdtemp(
+      path.join(os.tmpdir(), 'genkit-filesystem-test-')
+    );
+    await fs.writeFile(path.join(tempDir, 'image.png'), 'fake image content');
+    await fs.writeFile(path.join(tempDir, 'unknown.xyz'), 'unknown content');
+  });
+
+  afterEach(async () => {
+    await fs.rm(tempDir, { recursive: true, force: true });
+  });
+
+  function createToolModel(ai: any, toolName: string, input: any) {
+    let turn = 0;
+    return ai.defineModel(
+      { name: `pm-${toolName}-${Math.random()}` },
+      async () => {
+        turn++;
+        if (turn === 1) {
+          return {
+            message: {
+              role: 'model',
+              content: [{ toolRequest: { name: toolName, input } }],
+            },
+          };
+        }
+        return { message: { role: 'model', content: [{ text: 'done' }] } };
+      }
+    );
+  }
+
+  it('reads an image file as media', async () => {
+    const ai = genkit({});
+    const pm = createToolModel(ai, 'read_file', { filePath: 'image.png' });
+    const result = (await ai.generate({
+      model: pm,
+      prompt: 'test',
+      use: [filesystem({ rootDirectory: tempDir })],
+    })) as any;
+
+    const toolMsg = result.messages.find((m: any) => m.role === 'tool');
+    assert.ok(toolMsg);
+    assert.match(toolMsg.content[0].toolResponse.output, /read successfully/);
+
+    const userMsg = result.messages.find(
+      (m: any) => m.role === 'user' && m.content.some((c: any) => c.media)
+    );
+    assert.ok(userMsg);
+    const mediaPart = userMsg.content.find((c: any) => c.media);
+    assert.ok(mediaPart);
+    assert.strictEqual(mediaPart.media.contentType, 'image/png');
+    assert.ok(mediaPart.media.url.startsWith('data:image/png;base64,'));
+  });
+
+  it('reads unknown file as text', async () => {
+    const ai = genkit({});
+    const pm = createToolModel(ai, 'read_file', { filePath: 'unknown.xyz' });
+    const result = (await ai.generate({
+      model: pm,
+      prompt: 'test',
+      use: [filesystem({ rootDirectory: tempDir })],
+    })) as any;
+
+    const userMsg = result.messages.find(
+      (m: any) =>
+        m.role === 'user' &&
+        m.content.some((c: any) => c.text && c.text.includes('<read_file'))
+    );
+    assert.ok(userMsg);
+    assert.ok(userMsg.content[0].text.includes('unknown content'));
+    // Should NOT have media
+    assert.ok(!userMsg.content.some((c: any) => c.media));
+  });
+});
diff --git a/js/plugins/middleware/tests/filesystem_test.ts b/js/plugins/middleware/tests/filesystem_test.ts
new file mode 100644
index 0000000000..22839bf38d
--- /dev/null
+++ b/js/plugins/middleware/tests/filesystem_test.ts
@@ -0,0 +1,519 @@
+/**
+ * Copyright 2026 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import * as assert from 'assert';
+import * as fs from 'fs/promises';
+import { genkit } from 'genkit';
+import { afterEach, beforeEach, describe, it } from 'node:test';
+import * as os from 'os';
+import * as path from 'path';
+import { filesystem } from '../src/filesystem.js';
+
+describe('filesystem middleware', () => {
+  let tempDir: string;
+  let fakeGenerateAPI: any = {};
+
+  beforeEach(async () => {
+    tempDir = await fs.mkdtemp(
+      path.join(os.tmpdir(), 'genkit-filesystem-test-')
+    );
+    await fs.mkdir(path.join(tempDir, 'sub'));
+    await fs.writeFile(path.join(tempDir, 'file1.txt'), 'hello world');
+    await fs.writeFile(path.join(tempDir, 'sub', 'file2.txt'), 'sub file');
+  });
+
+  afterEach(async () => {
+    await fs.rm(tempDir, { recursive: true, force: true });
+  });
+
+  function createToolModel(ai: any, toolName: string, input: any) {
+    let turn = 0;
+    return ai.defineModel(
+      { name: `pm-${toolName}-${Math.random()}` },
+      async () => {
+        turn++;
+        if (turn === 1) {
+          return {
+            message: {
+              role: 'model',
+              content: [{ toolRequest: { name: toolName, input } }],
+            },
+          };
+        }
+        return { message: { role: 'model', content: [{ text: 'done' }] } };
+      }
+    );
+  }
+
+  it('fails if rootDirectory is not provided', () => {
+    assert.throws(
+      () => filesystem.instantiate({} as any, fakeGenerateAPI),
+      /requires a rootDirectory option/
+    );
+  });
+
+  it('injects tools', () => {
+    const mw = filesystem.instantiate(
+      { rootDirectory: tempDir },
+      fakeGenerateAPI
+    );
+    assert.ok(mw.tools);
+    assert.strictEqual(mw.tools.length, 4);
+    assert.strictEqual(mw.tools[0].__action.name, 'list_files');
+    assert.strictEqual(mw.tools[1].__action.name, 'read_file');
+    assert.strictEqual(mw.tools[2].__action.name, 'write_file');
+    assert.strictEqual(mw.tools[3].__action.name, 'search_and_replace');
+  });
+
+  describe('list_files', () => {
+    it('lists files in root directory', async () => {
+      const ai = genkit({});
+      const pm = createToolModel(ai, 'list_files', { dirPath: '' });
+      const result = (await ai.generate({
+        model: pm,
+        prompt: 'test',
+        use: [filesystem({ rootDirectory: tempDir })],
+      })) as any;
+
+      const toolMsg = result.messages.find((m: any) => m.role === 'tool');
+      assert.ok(toolMsg);
+      const output = toolMsg.content[0].toolResponse.output;
+      assert.ok(
+        output.find((r: any) => r.path === 'file1.txt' && !r.isDirectory)
+      );
+      assert.ok(output.find((r: any) => r.path === 'sub' && r.isDirectory));
+      assert.ok(
+        !output.find((r: any) => r.path === path.join('sub', 'file2.txt'))
+      );
+    });
+
+    it('lists files recursively', async () => {
+      const ai = genkit({});
+      const pm = createToolModel(ai, 'list_files', {
+        dirPath: '',
+        recursive: true,
+      });
+      const result = (await ai.generate({
+        model: pm,
+        prompt: 'test',
+        use: [filesystem({ rootDirectory: tempDir })],
+      })) as any;
+
+      const toolMsg = result.messages.find((m: any) => m.role === 'tool');
+      assert.ok(toolMsg);
+      const output = toolMsg.content[0].toolResponse.output;
+      assert.ok(
+        output.find((r: any) => r.path === 'file1.txt' && !r.isDirectory)
+      );
+      assert.ok(output.find((r: any) => r.path === 'sub' && r.isDirectory));
+      assert.ok(
+        output.find(
+          (r: any) => r.path === path.join('sub', 'file2.txt') && !r.isDirectory
+        )
+      );
+    });
+
+    it('rejects listing outside root directory', async () => {
+      const ai = genkit({});
+      const pm = createToolModel(ai, 'list_files', { dirPath: '../' });
+
+      // The middleware catches errors and injects user message.
+      // So verify that user message contains access denied error.
+      const result = (await ai.generate({
+        model: pm,
+        prompt: 'test',
+        use: [filesystem({ rootDirectory: tempDir })],
+      })) as any;
+
+      const userMsg = result.messages.find(
+        (m: any) =>
+          m.role === 'user' && m.content[0].text.includes('Access denied')
+      );
+      assert.ok(userMsg);
+    });
+  });
+
+  describe('read_file', () => {
+    it('reads a file in root directory', async () => {
+      const ai = genkit({});
+      const pm = createToolModel(ai, 'read_file', { filePath: 'file1.txt' });
+      const result = (await ai.generate({
+        model: pm,
+        prompt: 'test',
+        use: [filesystem({ rootDirectory: tempDir })],
+      })) as any;
+
+      const toolMsg = result.messages.find((m: any) => m.role === 'tool');
+      assert.ok(toolMsg);
+      assert.match(toolMsg.content[0].toolResponse.output, /read successfully/);
+
+      const userMsg = result.messages.find(
+        (m: any) =>
+          m.role === 'user' && m.content[0].text.includes('<read_file')
+      );
+      assert.ok(userMsg);
+      assert.ok(userMsg.content[0].text.includes('hello world'));
+    });
+
+    it('reads a file in sub directory', async () => {
+      const ai = genkit({});
+      const pm = createToolModel(ai, 'read_file', {
+        filePath: 'sub/file2.txt',
+      });
+      const result = (await ai.generate({
+        model: pm,
+        prompt: 'test',
+        use: [filesystem({ rootDirectory: tempDir })],
+      })) as any;
+
+      const toolMsg = result.messages.find((m: any) => m.role === 'tool');
+      assert.ok(toolMsg);
+      assert.match(toolMsg.content[0].toolResponse.output, /read successfully/);
+
+      const userMsg = result.messages.find(
+        (m: any) =>
+          m.role === 'user' && m.content[0].text.includes('<read_file')
+      );
+      assert.ok(userMsg);
+      assert.ok(userMsg.content[0].text.includes('sub file'));
+    });
+
+    it('rejects reading outside root directory', async () => {
+      const ai = genkit({});
+      const pm = createToolModel(ai, 'read_file', {
+        filePath: '../etc/passwd',
+      });
+
+      const result = (await ai.generate({
+        model: pm,
+        prompt: 'test',
+        use: [filesystem({ rootDirectory: tempDir })],
+      })) as any;
+
+      const userMsg = result.messages.find(
+        (m: any) =>
+          m.role === 'user' && m.content[0].text.includes('Access denied')
+      );
+      assert.ok(userMsg);
+    });
+  });
+
+  describe('write_file', () => {
+    it('writes a new file', async () => {
+      const ai = genkit({});
+      const pm = createToolModel(ai, 'write_file', {
+        filePath: 'new.txt',
+        content: 'new content',
+      });
+      const result = (await ai.generate({
+        model: pm,
+        prompt: 'test',
+        use: [filesystem({ rootDirectory: tempDir })],
+      })) as any;
+
+      const toolMsg = result.messages.find((m: any) => m.role === 'tool');
+      assert.ok(toolMsg);
+      assert.match(
+        toolMsg.content[0].toolResponse.output,
+        /written successfully/
+      );
+
+      const content = await fs.readFile(path.join(tempDir, 'new.txt'), 'utf8');
+      assert.strictEqual(content, 'new content');
+    });
+
+    it('creates directories if needed', async () => {
+      const ai = genkit({});
+      const pm = createToolModel(ai, 'write_file', {
+        filePath: 'deep/nested/file.txt',
+        content: 'nested content',
+      });
+      await ai.generate({
+        model: pm,
+        prompt: 'test',
+        use: [filesystem({ rootDirectory: tempDir })],
+      });
+
+      const content = await fs.readFile(
+        path.join(tempDir, 'deep/nested/file.txt'),
+        'utf8'
+      );
+      assert.strictEqual(content, 'nested content');
+    });
+  });
+
+  describe('search_and_replace', () => {
+    it('replaces content', async () => {
+      const ai = genkit({});
+      const editBlock = `<<<<<<< SEARCH
+hello world
+=======
+hello universe
+>>>>>>> REPLACE`;
+      const pm = createToolModel(ai, 'search_and_replace', {
+        filePath: 'file1.txt',
+        edits: [editBlock],
+      });
+
+      const result = (await ai.generate({
+        model: pm,
+        prompt: 'test',
+        use: [filesystem({ rootDirectory: tempDir })],
+      })) as any;
+
+      const toolMsg = result.messages.find((m: any) => m.role === 'tool');
+      if (!toolMsg) {
+        const errorMsg = result.messages.find(
+          (m: any) => m.role === 'user' && m.content[0].text.includes('failed')
+        );
+        if (errorMsg) {
+          throw new Error(
+            `Tool failed unexpectedly: ${errorMsg.content[0].text}`
+          );
+        }
+      }
+      assert.ok(toolMsg);
+      assert.match(
+        toolMsg.content[0].toolResponse.output,
+        /Successfully applied/
+      );
+
+      const content = await fs.readFile(
+        path.join(tempDir, 'file1.txt'),
+        'utf8'
+      );
+      assert.strictEqual(content, 'hello universe');
+    });
+
+    it('fails if search content not found', async () => {
+      const ai = genkit({});
+      const editBlock = `<<<<<<< SEARCH
+nonexistent
+=======
+replace
+>>>>>>> REPLACE`;
+      const pm = createToolModel(ai, 'search_and_replace', {
+        filePath: 'file1.txt',
+        edits: [editBlock],
+      });
+
+      const result = (await ai.generate({
+        model: pm,
+        prompt: 'test',
+        use: [filesystem({ rootDirectory: tempDir })],
+      })) as any;
+
+      const userMsg = result.messages.find(
+        (m: any) =>
+          m.role === 'user' &&
+          m.content[0].text.includes('Search content not found')
+      );
+      if (!userMsg) {
+        console.log(
+          'Messages received:',
+          JSON.stringify(result.messages, null, 2)
+        );
+      }
+      assert.ok(userMsg);
+    });
+
+    it('handles tricky search/replace cases', async () => {
+      const cases = [
+        {
+          name: 'marker in search',
+          initial: 'line1\n=======\nline2',
+          block: `<<<<<<< SEARCH
+line1
+=======
+line2
+=======
+replacement
+>>>>>>> REPLACE`,
+          expected: 'replacement',
+        },
+        {
+          name: 'marker in replace',
+          initial: 'original',
+          block: `<<<<<<< SEARCH
+original
+=======
+new
+=======
+line
+>>>>>>> REPLACE`,
+          expected: 'new\n=======\nline',
+        },
+        {
+          name: 'start marker in search',
+          initial: '<<<<<<< SEARCH\ncontent',
+          block: `<<<<<<< SEARCH
+<<<<<<< SEARCH
+content
+=======
+replaced
+>>>>>>> REPLACE`,
+          expected: 'replaced',
+        },
+        {
+          name: 'start marker in replace',
+          initial: 'content',
+          block: `<<<<<<< SEARCH
+content
+=======
+<<<<<<< SEARCH
+new
+>>>>>>> REPLACE`,
+          expected: '<<<<<<< SEARCH\nnew',
+        },
+        {
+          name: 'end marker in search',
+          initial: 'content\n>>>>>>> REPLACE',
+          block: `<<<<<<< SEARCH
+content
+>>>>>>> REPLACE
+=======
+replaced
+>>>>>>> REPLACE`,
+          expected: 'replaced',
+        },
+        {
+          name: 'end marker in replace',
+          initial: 'content',
+          block: `<<<<<<< SEARCH
+content
+=======
+new
+>>>>>>> REPLACE
+>>>>>>> REPLACE`,
+          expected: 'new\n>>>>>>> REPLACE',
+        },
+        {
+          name: 'multiple markers greedy search',
+          initial: 'part1\n=======\npart2',
+          block: `<<<<<<< SEARCH
+part1
+=======
+part2
+=======
+replacement
+>>>>>>> REPLACE`,
+          expected: 'replacement',
+        },
+        {
+          name: 'ambiguous separators preferring longest match',
+          initial: 'A\n=======\nB',
+          // search: A\n=======\nB -> replace: C\n=======\nD
+          // block structure: A = B = C = D (where = is separator)
+          // splits:
+          // 1. S=A, R=B=C=D. (Match A? Yes)
+          // 2. S=A=B, R=C=D. (Match A=B? Yes)
+          // 3. S=A=B=C, R=D. (Match A=B=C? No)
+          // Winner: 2.
+          block: `<<<<<<< SEARCH
+A
+=======
+B
+=======
+C
+=======
+D
+>>>>>>> REPLACE`,
+          expected: 'C\n=======\nD',
+        },
+      ];
+
+      for (const c of cases) {
+        const ai = genkit({});
+        const filename = `tricky-${c.name.replace(/\s+/g, '-')}.txt`;
+        await fs.writeFile(path.join(tempDir, filename), c.initial);
+
+        const pm = createToolModel(ai, 'search_and_replace', {
+          filePath: filename,
+          edits: [c.block],
+        });
+
+        const result = (await ai.generate({
+          model: pm,
+          prompt: 'test',
+          use: [filesystem({ rootDirectory: tempDir })],
+        })) as any;
+
+        const toolMsg = result.messages.find((m: any) => m.role === 'tool');
+        assert.ok(toolMsg, `Tool execution failed for case: ${c.name}`);
+        assert.match(
+          toolMsg.content[0].toolResponse.output,
+          /Successfully applied/,
+          `Tool output mismatch for case: ${c.name}`
+        );
+
+        const newContent = await fs.readFile(
+          path.join(tempDir, filename),
+          'utf8'
+        );
+        assert.strictEqual(
+          newContent,
+          c.expected,
+          `Content mismatch for case: ${c.name}`
+        );
+      }
+    });
+  });
+
+  describe('robustness', () => {
+    it('should handle tool errors gracefully by injecting user message', async () => {
+      const ai = genkit({});
+      const pm = createToolModel(ai, 'read_file', { filePath: 'nonexistent' });
+
+      const result = (await ai.generate({
+        model: pm,
+        prompt: 'start',
+        use: [filesystem({ rootDirectory: tempDir })],
+      })) as any;
+
+      const messages = result.messages;
+      const lastModelIndex = messages.findLastIndex(
+        (m: any) => m.role === 'model' && m.content[0].toolRequest
+      );
+      const injectedUserIndex = messages.findIndex(
+        (m: any) =>
+          m.role === 'user' &&
+          m.content[0].text.includes("Tool 'read_file' failed")
+      );
+
+      assert.ok(
+        injectedUserIndex > lastModelIndex,
+        'User message should appear after tool request'
+      );
+
+      const userMsg = messages[injectedUserIndex];
+      assert.match(
+        userMsg.content[0].text,
+        /Tool 'read_file' failed: .*ENOENT.*/,
+        'Error message should contain underlying error details'
+      );
+
+      const roles = messages.map((m: any) => m.role);
+      assert.deepStrictEqual(roles, ['user', 'model', 'user', 'model']);
+
+      const toolMsg = messages.find((m: any) => m.role === 'tool');
+      assert.strictEqual(
+        toolMsg,
+        undefined,
+        'Tool message should not be present'
+      );
+    });
+  });
+});
diff --git a/js/plugins/middleware/tests/retry_test.ts b/js/plugins/middleware/tests/retry_test.ts
new file mode 100644
index 0000000000..cb722e1eeb
--- /dev/null
+++ b/js/plugins/middleware/tests/retry_test.ts
@@ -0,0 +1,314 @@
+/**
+ * Copyright 2026 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import * as assert from 'assert';
+import { GenkitError, genkit } from 'genkit';
+import { describe, it } from 'node:test';
+import { TEST_ONLY, retry } from '../src/retry.js';
+
+describe('retry', () => {
+  it('should not retry on success', async () => {
+    let requestCount = 0;
+    const ai = genkit({});
+    const pm = ai.defineModel({ name: 'programmableModel' }, async (req) => {
+      requestCount++;
+      return { message: { role: 'model', content: [{ text: 'success' }] } };
+    });
+
+    const result = await ai.generate({
+      model: pm,
+      prompt: 'test',
+      use: [retry()],
+    });
+
+    assert.strictEqual(requestCount, 1);
+    assert.strictEqual(result.text, 'success');
+  });
+
+  it('should retry on a retryable GenkitError', async () => {
+    let requestCount = 0;
+    const ai = genkit({});
+    const pm = ai.defineModel({ name: 'programmableModel' }, async (req) => {
+      requestCount++;
+      if (requestCount < 3) {
+        throw new GenkitError({ status: 'UNAVAILABLE', message: 'test' });
+      }
+      return { message: { role: 'model', content: [{ text: 'success' }] } };
+    });
+
+    TEST_ONLY.setRetryTimeout((callback, ms) => {
+      callback();
+      return 0 as any;
+    });
+
+    const result = await ai.generate({
+      model: pm,
+      prompt: 'test',
+      use: [retry({ maxRetries: 3 })],
+    });
+
+    assert.strictEqual(requestCount, 3);
+    assert.strictEqual(result.text, 'success');
+  });
+
+  it('should retry on a non-GenkitError', async () => {
+    let requestCount = 0;
+    const ai = genkit({});
+    const pm = ai.defineModel({ name: 'programmableModel' }, async (req) => {
+      requestCount++;
+      if (requestCount < 2) {
+        throw new Error('generic error');
+      }
+      return { message: { role: 'model', content: [{ text: 'success' }] } };
+    });
+
+    TEST_ONLY.setRetryTimeout((callback, ms) => {
+      callback();
+      return 0 as any;
+    });
+
+    const result = await ai.generate({
+      model: pm,
+      prompt: 'test',
+      use: [retry({ maxRetries: 2 })],
+    });
+
+    assert.strictEqual(requestCount, 2);
+    assert.strictEqual(result.text, 'success');
+  });
+
+  it('should throw after exhausting retries', async () => {
+    let requestCount = 0;
+    const ai = genkit({});
+    const pm = ai.defineModel({ name: 'programmableModel' }, async (req) => {
+      requestCount++;
+      throw new GenkitError({ status: 'UNAVAILABLE', message: 'test' });
+    });
+
+    TEST_ONLY.setRetryTimeout((callback, ms) => {
+      callback();
+      return 0 as any;
+    });
+
+    await assert.rejects(
+      ai.generate({
+        model: pm,
+        prompt: 'test',
+        use: [retry({ maxRetries: 2 })],
+      }),
+      /UNAVAILABLE: test/
+    );
+
+    assert.strictEqual(requestCount, 3);
+  });
+
+  it('should call onError callback', async () => {
+    let requestCount = 0;
+    const ai = genkit({});
+    const pm = ai.defineModel({ name: 'programmableModel' }, async (req) => {
+      requestCount++;
+      throw new Error('test error');
+    });
+
+    TEST_ONLY.setRetryTimeout((callback, ms) => {
+      callback();
+      return 0 as any;
+    });
+
+    let errorCount = 0;
+    let lastError: Error | undefined;
+    await assert.rejects(
+      ai.generate({
+        model: pm,
+        prompt: 'test',
+        use: [
+          retry({
+            maxRetries: 2,
+            onError: (err, attempt) => {
+              errorCount++;
+              lastError = err;
+              assert.strictEqual(attempt, errorCount);
+            },
+          }),
+        ],
+      }),
+      /test error/
+    );
+
+    assert.strictEqual(requestCount, 3);
+    assert.strictEqual(errorCount, 2);
+    assert.ok(lastError);
+    assert.strictEqual(lastError!.message, 'test error');
+  });
+
+  it('should not retry on non-retryable status', async () => {
+    let requestCount = 0;
+    const ai = genkit({});
+    const pm = ai.defineModel({ name: 'programmableModel' }, async (req) => {
+      requestCount++;
+      throw new GenkitError({ status: 'INVALID_ARGUMENT', message: 'test' });
+    });
+
+    await assert.rejects(
+      ai.generate({
+        model: pm,
+        prompt: 'test',
+        use: [retry({ maxRetries: 2 })],
+      }),
+      /INVALID_ARGUMENT: test/
+    );
+
+    assert.strictEqual(requestCount, 1);
+  });
+
+  it('should respect initial delay', async () => {
+    let requestCount = 0;
+    const ai = genkit({});
+    const pm = ai.defineModel({ name: 'programmableModel' }, async (req) => {
+      requestCount++;
+      if (requestCount < 2) {
+        throw new Error('generic error');
+      }
+      return { message: { role: 'model', content: [{ text: 'success' }] } };
+    });
+
+    let totalDelay = 0;
+    TEST_ONLY.setRetryTimeout((callback, ms) => {
+      totalDelay += ms!;
+      callback();
+      return 0 as any;
+    });
+
+    const result = await ai.generate({
+      model: pm,
+      prompt: 'test',
+      use: [retry({ maxRetries: 2, initialDelayMs: 50, noJitter: true })],
+    });
+
+    assert.strictEqual(requestCount, 2);
+    assert.strictEqual(result.text, 'success');
+    assert.strictEqual(totalDelay, 50);
+  });
+
+  it('should respect backoff factor', async () => {
+    let requestCount = 0;
+    const ai = genkit({});
+    const pm = ai.defineModel({ name: 'programmableModel' }, async (req) => {
+      requestCount++;
+      if (requestCount < 3) {
+        throw new Error('generic error');
+      }
+      return { message: { role: 'model', content: [{ text: 'success' }] } };
+    });
+
+    let totalDelay = 0;
+    TEST_ONLY.setRetryTimeout((callback, ms) => {
+      totalDelay += ms!;
+      callback();
+      return 0 as any;
+    });
+
+    const result = await ai.generate({
+      model: pm,
+      prompt: 'test',
+      use: [
+        retry({
+          maxRetries: 3,
+          initialDelayMs: 20,
+          backoffFactor: 2,
+          noJitter: true,
+        }),
+      ],
+    });
+
+    assert.strictEqual(requestCount, 3);
+    assert.strictEqual(result.text, 'success');
+    assert.strictEqual(totalDelay, 20 + 40);
+  });
+
+  it('should apply jitter', async () => {
+    let requestCount = 0;
+    const ai = genkit({});
+    const pm = ai.defineModel({ name: 'programmableModel' }, async (req) => {
+      requestCount++;
+      if (requestCount < 2) {
+        throw new Error('generic error');
+      }
+      return { message: { role: 'model', content: [{ text: 'success' }] } };
+    });
+
+    let totalDelay = 0;
+    TEST_ONLY.setRetryTimeout((callback, ms) => {
+      totalDelay += ms!;
+      callback();
+      return 0 as any;
+    });
+
+    const result = await ai.generate({
+      model: pm,
+      prompt: 'test',
+      use: [
+        retry({
+          maxRetries: 2,
+          initialDelayMs: 50,
+          noJitter: false, // do jitter
+        }),
+      ],
+    });
+
+    assert.strictEqual(requestCount, 2);
+    assert.strictEqual(result.text, 'success');
+    assert.ok(totalDelay >= 50);
+    assert.ok(totalDelay <= 1050);
+  });
+
+  it('should respect max delay', async () => {
+    let requestCount = 0;
+    const ai = genkit({});
+    const pm = ai.defineModel({ name: 'programmableModel' }, async (req) => {
+      requestCount++;
+      if (requestCount < 3) {
+        throw new Error('generic error');
+      }
+      return { message: { role: 'model', content: [{ text: 'success' }] } };
+    });
+
+    let totalDelay = 0;
+    TEST_ONLY.setRetryTimeout((callback, ms) => {
+      totalDelay += ms!;
+      callback();
+      return 0 as any;
+    });
+
+    const result = await ai.generate({
+      model: pm,
+      prompt: 'test',
+      use: [
+        retry({
+          maxRetries: 3,
+          initialDelayMs: 50,
+          maxDelayMs: 60,
+          backoffFactor: 2,
+          noJitter: true,
+        }),
+      ],
+    });
+
+    assert.strictEqual(requestCount, 3);
+    assert.strictEqual(result.text, 'success');
+    assert.strictEqual(totalDelay, 50 + 60);
+  });
+});
diff --git a/js/plugins/middleware/tsconfig.json b/js/plugins/middleware/tsconfig.json
new file mode 100644
index 0000000000..596e2cf729
--- /dev/null
+++ b/js/plugins/middleware/tsconfig.json
@@ -0,0 +1,4 @@
+{
+  "extends": "../../tsconfig.json",
+  "include": ["src"]
+}
diff --git a/js/plugins/middleware/tsup.config.ts b/js/plugins/middleware/tsup.config.ts
new file mode 100644
index 0000000000..c36c8e05fa
--- /dev/null
+++ b/js/plugins/middleware/tsup.config.ts
@@ -0,0 +1,22 @@
+/**
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { defineConfig, type Options } from 'tsup';
+import { defaultOptions } from '../../tsup.common';
+
+export default defineConfig({
+  ...(defaultOptions as Options),
+});
diff --git a/js/plugins/middleware/typedoc.json b/js/plugins/middleware/typedoc.json
new file mode 100644
index 0000000000..35fed2c958
--- /dev/null
+++ b/js/plugins/middleware/typedoc.json
@@ -0,0 +1,3 @@
+{
+  "entryPoints": ["src/index.ts"]
+}
diff --git a/js/pnpm-lock.yaml b/js/pnpm-lock.yaml
index 8b4034bd80..4fecbe6760 100644
--- a/js/pnpm-lock.yaml
+++ b/js/pnpm-lock.yaml
@@ -853,6 +853,40 @@ importers:
         specifier: ^5.3.0
         version: 5.8.3
 
+  plugins/middleware:
+    dependencies:
+      genkit:
+        specifier: workspace:^
+        version: link:../../genkit
+      mime-types:
+        specifier: ^3.0.2
+        version: 3.0.2
+    devDependencies:
+      '@genkit-ai/google-genai':
+        specifier: workspace:^
+        version: link:../google-genai
+      '@types/mime-types':
+        specifier: ^3.0.1
+        version: 3.0.1
+      '@types/node':
+        specifier: ^20.11.16
+        version: 20.19.1
+      npm-run-all:
+        specifier: ^4.1.5
+        version: 4.1.5
+      rimraf:
+        specifier: ^6.0.1
+        version: 6.0.1
+      tsup:
+        specifier: ^8.0.2
+        version: 8.5.0(postcss@8.4.47)(tsx@4.20.3)(typescript@4.9.5)(yaml@2.8.0)
+      tsx:
+        specifier: ^4.7.0
+        version: 4.20.3
+      typescript:
+        specifier: ^4.9.0
+        version: 4.9.5
+
   plugins/next:
     devDependencies:
       '@jest/globals':
@@ -4406,6 +4440,9 @@ packages:
   '@types/memcached@2.2.10':
     resolution: {integrity: sha512-AM9smvZN55Gzs2wRrqeMHVP7KE8KWgCJO/XL5yCly2xF6EKa4YlbpK+cLSAH4NG/Ah64HrlegmGqW8kYws7Vxg==}
 
+  '@types/mime-types@3.0.1':
+    resolution: {integrity: sha512-xRMsfuQbnRq1Ef+C+RKaENOxXX87Ygl38W1vDfPHRku02TgQr+Qd8iivLtAMcR0KF5/29xlnFihkTlbqFrGOVQ==}
+
   '@types/mime@1.3.5':
     resolution: {integrity: sha512-/pyBZWSLD2n0dcHE3hq8s8ZvcETHtEuF+3E7XVt0Ig2nvsVQXdghHVcEkIWjy9A0wKfTn97a/PSDYohKIlnP/w==}
 
@@ -7162,6 +7199,10 @@ packages:
     resolution: {integrity: sha512-xRc4oEhT6eaBpU1XF7AjpOFD+xQmXNB5OVKwp4tqCuBpHLS/ZbBDrc07mYTDqVMg6PfxUjjNp85O6Cd2Z/5HWA==}
     engines: {node: '>= 0.6'}
 
+  mime-types@3.0.2:
+    resolution: {integrity: sha512-Lbgzdk0h4juoQ9fCKXW4by0UJqj+nOOrI9MJ1sSj4nI8aI2eo1qmvQEie4VD1glsS250n15LsWsYtCugiStS5A==}
+    engines: {node: '>=18'}
+
   mime@1.6.0:
     resolution: {integrity: sha512-x0Vn8spI+wuJ1O6S7gnbaQg8Pxh4NNHb7KSINmEWKiPE4RKOplvijn+NkmYmmRgP68mc70j2EbeTFRsrswaQeg==}
     engines: {node: '>=4'}
@@ -11729,6 +11770,8 @@ snapshots:
     dependencies:
       '@types/node': 20.19.1
 
+  '@types/mime-types@3.0.1': {}
+
   '@types/mime@1.3.5': {}
 
   '@types/mime@3.0.4': {}
@@ -11861,7 +11904,7 @@ snapshots:
 
   accepts@2.0.0:
     dependencies:
-      mime-types: 3.0.1
+      mime-types: 3.0.2
       negotiator: 1.0.0
 
   acorn-import-attributes@1.9.5(acorn@8.11.3):
@@ -15216,6 +15259,10 @@ snapshots:
     dependencies:
       mime-db: 1.54.0
 
+  mime-types@3.0.2:
+    dependencies:
+      mime-db: 1.54.0
+
   mime@1.6.0: {}
 
   mime@2.6.0: {}
@@ -16280,7 +16327,7 @@ snapshots:
       etag: 1.8.1
       fresh: 2.0.0
       http-errors: 2.0.0
-      mime-types: 3.0.1
+      mime-types: 3.0.2
       ms: 2.1.3
       on-finished: 2.4.1
       range-parser: 1.2.1
@@ -16980,7 +17027,7 @@ snapshots:
     dependencies:
       content-type: 1.0.5
       media-typer: 1.1.0
-      mime-types: 3.0.1
+      mime-types: 3.0.2
 
   typed-array-buffer@1.0.3:
     dependencies: