Pipes MCP Template

A starter template for building an MCP server with human-approved, provider-scoped access to third-party APIs using WorkOS Pipes. It shows one way to let AI assistants securely interact with services like Linear, Notion, Snowflake, and more with a human in the loop, without trying to prescribe the full deployment story or how approval requests should be delivered.

What’s included

• Human-in-the-loop approval flow — AI assistants request access, humans approve via a browser-based consent screen
• Provider-scoped authority — humans select exactly which integrations to authorize (not all-or-nothing)
• Unified authority grants — broad and per-request approvals share one AuthorityGrant model
• Time-limited sessions — authority expires after 5 minutes, configurable
• Read/write gating — read and write operations are gated separately
• Approval polling — assistants poll for results and receive user instructions

The approval flow

sequenceDiagram
       participant AI as AI Assistant
       participant Server as This Server
       participant Human as Human

       AI->>Server: request_elevated_access(reason, providers)
       Server-->>AI: approval URL + request ID

       AI->>Human: "Open this URL"

       Human->>Server: select providers
       Human->>Server: add notes (optional)
       Human->>Server: approve / deny

       AI->>Server: check_access_request
       Server-->>AI: approved + providers
       Server-->>AI: user instructions

       AI->>Server: call_integration_api
       Server-->>AI: API response

Broad authority and per-request approval now use the same underlying grant record:

• kind: "broad" grants temporary session authority for selected providers
• kind: "request" approves one exact API call and is consumed on execution

Authorization structure

Every MCP request is authenticated first, then authorized from the current Pipes session and grant state:

1. app/[transport]/route.ts requires AuthKit authentication for every MCP request.
2. lib/mcp/with-authkit.ts verifies the bearer token, loads the WorkOS user, and loads or creates a Redis-backed PipesSession keyed by sid + organizationId.
3. Effective MCP scopes are derived from the session’s current broad authority, not directly from JWT claims.
4. request_elevated_access creates pending AuthorityGrant records:
   • broad grants request temporary read or write authority for selected providers
   • request grants store the exact url, method, and optional body for one API call
5. The approval UI resolves that grant:
   • approved broad grants become session.activeGrant
   • approved request grants stay in Redis as single-use approved grants
6. call_integration_api enforces access by either:
   • checking the active broad grant for read/write level and provider access
   • or consuming a matching approved request grant bound to the same sid, userId, and organizationId

Quick start

Prerequisites

• Node.js 20+
• pnpm
• Redis
• A WorkOS account with AuthKit and Pipes configured

1. Install dependencies

pnpm install

2. Start Redis

Redis is required for session and approval state storage.

# macOS (Homebrew)
brew install redis
brew services start redis

# Docker
docker run -d -p 6379:6379 redis

# Or run directly
redis-server

Verify it’s running:

redis-cli ping
# PONG

3. Configure environment

cp .env.local.example .env.local

Fill in your values:

WORKOS_API_KEY=sk_test_...
WORKOS_CLIENT_ID=client_...
WORKOS_COOKIE_PASSWORD=
WORKOS_REDIRECT_URI=http://localhost:5711/callback
AUTHKIT_DOMAIN=auth.workos.com
REDIS_URL=redis://127.0.0.1:6379

Optional tuning:

SESSION_TTL_MS=604800000          # Session store TTL (default: 7 days)
SESSION_AUTHORITY_TTL_MS=300000   # Authority expiry (default: 5 minutes)

4. Start the dev server

pnpm dev

The server starts at http://localhost:5711.

Connecting an MCP client

Point your MCP client (Claude Code, Claude Desktop, Cursor, etc.) at the server URL. The server uses Streamable HTTP transport at http://localhost:5711/mcp.

Adding a new provider

1. Add a new provider module in lib/mcp/providers/ that exports a ProviderDefinition
2. Implement matchesUrl, buildHeaders, and, if needed, isWriteOperation for provider-specific write detection
3. Register the provider in lib/mcp/providers/index.ts
4. Update lib/mcp/token-injection.ts only if the provider needs auth behavior beyond the default Bearer token injection
5. Configure the integration in your WorkOS dashboard

The call_integration_api tool auto-detects the provider from the API URL domain and injects the correct authentication headers.

Redis keys

Development

pnpm dev          # Start dev server (Turbopack)
pnpm typecheck    # Type check
pnpm lint         # Lint (Biome)
pnpm format       # Format (Biome)

Contributing

See CONTRIBUTING.md for guidelines on how to contribute to this project.

License

MIT License. See LICENSE for details.