feat(copilot): copilot mcp + server side copilot execution (#3173)

* v0

* v1

* Basic ss tes

* Ss tests

* Stuff

* Add mcp

* mcp v1

* Improvement

* Fix

* BROKEN

* Checkpoint

* Streaming

* Fix abort

* Things are broken

* Streaming seems to work but copilot is dumb

* Fix edge issue

* LUAAAA

* Fix stream buffer

* Fix lint

* Checkpoint

* Initial temp state, in the middle of a refactor

* Initial test shows diff store still working

* Tool refactor

* First cleanup pass complete - untested

* Continued cleanup

* Refactor

* Refactor complete - no testing yet

* Fix - cursor makes me sad

* Fix mcp

* Clean up mcp

* Updated mcp

* Add respond to subagents

* Fix definitions

* Add tools

* Add tools

* Add copilot mcp tracking

* Fix lint

* Fix mcp

* Fix

* Updates

* Clean up mcp

* Fix copilot mcp tool names to be sim prefixed

* Add opus 4.6

* Fix discovery tool

* Fix

* Remove logs

* Fix go side tool rendering

* Update docs

* Fix hydration

* Fix tool call resolution

* Fix

* Fix lint

* Fix superagent and autoallow integrations

* Fix always allow

* Update block

* Remove plan docs

* Fix hardcoded ff

* Fix dropped provider

* Fix lint

* Fix tests

* Fix dead messages array

* Fix discovery

* Fix run workflow

* Fix run block

* Fix run from block in copilot

* Fix lint

* Fix skip and mtb

* Fix typing

* Fix tool call

* Bump api version

* Fix bun lock

* Nuke bad files

Author: Sg312

apps/docs/content/docs/en/copilot/index.mdx

@@ -56,7 +56,7 @@ Switch between modes using the mode selector at the bottom of the input area.
 Select your preferred AI model using the model selector at the bottom right of the input area.
 
 **Available Models:**
-- Claude 4.5 Opus, Sonnet (default), Haiku
+- Claude 4.6 Opus (default), 4.5 Opus, Sonnet, Haiku
 - GPT 5.2 Codex, Pro
 - Gemini 3 Pro
 
@@ -190,3 +190,99 @@ Copilot usage is billed per token from the underlying LLM. If you reach your usa
 <Callout type="info">
   See the [Cost Calculation page](/execution/costs) for billing details.
 </Callout>
+## Copilot MCP
+
+You can use Copilot as an MCP server in your favorite editor or AI client. This lets you build, test, deploy, and manage Sim workflows directly from tools like Cursor, Claude Code, Claude Desktop, and VS Code.
+
+### Generating a Copilot API Key
+
+To connect to the Copilot MCP server, you need a **Copilot API key**:
+
+1. Go to [sim.ai](https://sim.ai) and sign in
+2. Navigate to **Settings** → **Copilot**
+3. Click **Generate API Key**
+4. Copy the key — it is only shown once
+
+The key will look like `sk-sim-copilot-...`. You will use this in the configuration below.
+
+### Cursor
+
+Add the following to your `.cursor/mcp.json` (project-level) or global Cursor MCP settings:
+
+```json
+{
+  "mcpServers": {
+    "sim-copilot": {
+      "url": "https://www.sim.ai/api/mcp/copilot",
+      "headers": {
+        "X-API-Key": "YOUR_COPILOT_API_KEY"
+      }
+    }
+  }
+}
+```
+
+Replace `YOUR_COPILOT_API_KEY` with the key you generated above.
+
+### Claude Code
+
+Run the following command to add the Copilot MCP server:
+
+```bash
+claude mcp add sim-copilot \
+  --transport http \
+  https://www.sim.ai/api/mcp/copilot \
+  --header "X-API-Key: YOUR_COPILOT_API_KEY"
+```
+
+Replace `YOUR_COPILOT_API_KEY` with your key.
+
+### Claude Desktop
+
+Claude Desktop requires [`mcp-remote`](https://www.npmjs.com/package/mcp-remote) to connect to HTTP-based MCP servers. Add the following to your Claude Desktop config file (`~/Library/Application Support/Claude/claude_desktop_config.json` on macOS):
+
+```json
+{
+  "mcpServers": {
+    "sim-copilot": {
+      "command": "npx",
+      "args": [
+        "-y",
+        "mcp-remote",
+        "https://www.sim.ai/api/mcp/copilot",
+        "--header",
+        "X-API-Key: YOUR_COPILOT_API_KEY"
+      ]
+    }
+  }
+}
+```
+
+Replace `YOUR_COPILOT_API_KEY` with your key.
+
+### VS Code
+
+Add the following to your VS Code `settings.json` or workspace `.vscode/settings.json`:
+
+```json
+{
+  "mcp": {
+    "servers": {
+      "sim-copilot": {
+        "type": "http",
+        "url": "https://www.sim.ai/api/mcp/copilot",
+        "headers": {
+          "X-API-Key": "YOUR_COPILOT_API_KEY"
+        }
+      }
+    }
+  }
+}
+```
+
+Replace `YOUR_COPILOT_API_KEY` with your key.
+
+<Callout type="info">
+  For self-hosted deployments, replace `https://www.sim.ai` with your self-hosted Sim URL.
+</Callout>
+

apps/sim/app/.well-known/oauth-authorization-server/[...issuer]/route.ts

@@ -0,0 +1,6 @@
+import type { NextRequest, NextResponse } from 'next/server'
+import { createMcpAuthorizationServerMetadataResponse } from '@/lib/mcp/oauth-discovery'
+
+export async function GET(request: NextRequest): Promise<NextResponse> {
+  return createMcpAuthorizationServerMetadataResponse(request)
+}

apps/sim/app/.well-known/oauth-authorization-server/api/mcp/copilot/route.ts

@@ -0,0 +1,6 @@
+import type { NextRequest, NextResponse } from 'next/server'
+import { createMcpAuthorizationServerMetadataResponse } from '@/lib/mcp/oauth-discovery'
+
+export async function GET(request: NextRequest): Promise<NextResponse> {
+  return createMcpAuthorizationServerMetadataResponse(request)
+}

apps/sim/app/.well-known/oauth-authorization-server/route.ts

@@ -0,0 +1,6 @@
+import type { NextRequest, NextResponse } from 'next/server'
+import { createMcpAuthorizationServerMetadataResponse } from '@/lib/mcp/oauth-discovery'
+
+export async function GET(request: NextRequest): Promise<NextResponse> {
+  return createMcpAuthorizationServerMetadataResponse(request)
+}

apps/sim/app/.well-known/oauth-protected-resource/api/mcp/copilot/route.ts

@@ -0,0 +1,6 @@
+import type { NextRequest, NextResponse } from 'next/server'
+import { createMcpProtectedResourceMetadataResponse } from '@/lib/mcp/oauth-discovery'
+
+export async function GET(request: NextRequest): Promise<NextResponse> {
+  return createMcpProtectedResourceMetadataResponse(request)
+}

apps/sim/app/.well-known/oauth-protected-resource/route.ts

@@ -0,0 +1,6 @@
+import type { NextRequest, NextResponse } from 'next/server'
+import { createMcpProtectedResourceMetadataResponse } from '@/lib/mcp/oauth-discovery'
+
+export async function GET(request: NextRequest): Promise<NextResponse> {
+  return createMcpProtectedResourceMetadataResponse(request)
+}

apps/sim/app/api/billing/update-cost/route.ts

@@ -18,6 +18,7 @@ const UpdateCostSchema = z.object({
   model: z.string().min(1, 'Model is required'),
   inputTokens: z.number().min(0).default(0),
   outputTokens: z.number().min(0).default(0),
+  source: z.enum(['copilot', 'mcp_copilot']).default('copilot'),
 })
 
 /**
@@ -75,12 +76,14 @@ export async function POST(req: NextRequest) {
       )
     }
 
-    const { userId, cost, model, inputTokens, outputTokens } = validation.data
+    const { userId, cost, model, inputTokens, outputTokens, source } = validation.data
+    const isMcp = source === 'mcp_copilot'
 
     logger.info(`[${requestId}] Processing cost update`, {
       userId,
       cost,
       model,
+      source,
     })
 
     // Check if user stats record exists (same as ExecutionLogger)
@@ -96,7 +99,7 @@ export async function POST(req: NextRequest) {
       return NextResponse.json({ error: 'User stats record not found' }, { status: 500 })
     }
 
-    const updateFields = {
+    const updateFields: Record<string, unknown> = {
       totalCost: sql`total_cost + ${cost}`,
       currentPeriodCost: sql`current_period_cost + ${cost}`,
       totalCopilotCost: sql`total_copilot_cost + ${cost}`,
@@ -105,17 +108,24 @@ export async function POST(req: NextRequest) {
       lastActive: new Date(),
     }
 
+    // Also increment MCP-specific counters when source is mcp_copilot
+    if (isMcp) {
+      updateFields.totalMcpCopilotCost = sql`total_mcp_copilot_cost + ${cost}`
+      updateFields.currentPeriodMcpCopilotCost = sql`current_period_mcp_copilot_cost + ${cost}`
+    }
+
     await db.update(userStats).set(updateFields).where(eq(userStats.userId, userId))
 
     logger.info(`[${requestId}] Updated user stats record`, {
       userId,
       addedCost: cost,
+      source,
     })
 
     // Log usage for complete audit trail
     await logModelUsage({
       userId,
-      source: 'copilot',
+      source: isMcp ? 'mcp_copilot' : 'copilot',
       model,
       inputTokens,
       outputTokens,

apps/sim/app/api/copilot/api-keys/generate/route.ts

@@ -1,7 +1,7 @@
 import { type NextRequest, NextResponse } from 'next/server'
 import { z } from 'zod'
 import { getSession } from '@/lib/auth'
-import { SIM_AGENT_API_URL_DEFAULT } from '@/lib/copilot/constants'
+import { SIM_AGENT_API_URL } from '@/lib/copilot/constants'
 import { env } from '@/lib/core/config/env'
 
 const GenerateApiKeySchema = z.object({
@@ -17,9 +17,6 @@ export async function POST(req: NextRequest) {
 
     const userId = session.user.id
 
-    // Move environment variable access inside the function
-    const SIM_AGENT_API_URL = env.SIM_AGENT_API_URL || SIM_AGENT_API_URL_DEFAULT
-
     const body = await req.json().catch(() => ({}))
     const validationResult = GenerateApiKeySchema.safeParse(body)
 

apps/sim/app/api/copilot/api-keys/route.test.ts

@@ -19,6 +19,7 @@ describe('Copilot API Keys API Route', () => {
 
     vi.doMock('@/lib/copilot/constants', () => ({
       SIM_AGENT_API_URL_DEFAULT: 'https://agent.sim.example.com',
+      SIM_AGENT_API_URL: 'https://agent.sim.example.com',
     }))
 
     vi.doMock('@/lib/core/config/env', async () => {

apps/sim/app/api/copilot/api-keys/route.ts

@@ -1,6 +1,6 @@
 import { type NextRequest, NextResponse } from 'next/server'
 import { getSession } from '@/lib/auth'
-import { SIM_AGENT_API_URL_DEFAULT } from '@/lib/copilot/constants'
+import { SIM_AGENT_API_URL } from '@/lib/copilot/constants'
 import { env } from '@/lib/core/config/env'
 
 export async function GET(request: NextRequest) {
@@ -12,8 +12,6 @@ export async function GET(request: NextRequest) {
 
     const userId = session.user.id
 
-    const SIM_AGENT_API_URL = env.SIM_AGENT_API_URL || SIM_AGENT_API_URL_DEFAULT
-
     const res = await fetch(`${SIM_AGENT_API_URL}/api/validate-key/get-api-keys`, {
       method: 'POST',
       headers: {
@@ -68,8 +66,6 @@ export async function DELETE(request: NextRequest) {
       return NextResponse.json({ error: 'id is required' }, { status: 400 })
     }
 
-    const SIM_AGENT_API_URL = env.SIM_AGENT_API_URL || SIM_AGENT_API_URL_DEFAULT
-
     const res = await fetch(`${SIM_AGENT_API_URL}/api/validate-key/delete`, {
       method: 'POST',
       headers: {