MCP developer guide
Expose a compatible discovery endpoint for a PatternLab Workspace.
Supported transport
Use a public HTTPS Streamable HTTP endpoint implementing MCP protocol 2026-07-28. PatternLab sends tools/list and accepts JSON or a bounded server-sent event response. Server redirects, private network destinations and external authentication are not supported.
Connection behavior
PatternLab validates the endpoint, requests the tool list and saves tool names and descriptions as a source snapshot. It does not call tools/call, enumerate resources, paginate tool lists or pass user credentials.
If the server returns a continuation cursor, the saved snapshot marks that more tools are available. Reconnecting refreshes the discovery response.
Integration checklist
- Serve tools/list using the current supported protocol and transport.
- Keep the discovery response below 2 MB and saved text below 200,000 characters.
- Connect the endpoint through + MCP in an authenticated Workspace.
- Inspect the saved descriptions in Sources. Do not treat discovery as permission to execute a tool.
Authentication boundary
PatternLab sign-in controls access to the Workspace. It is not authentication to your MCP server. A server that requires its own OAuth flow or bearer token cannot currently be connected. No public PatternLab API or webhook integration is available.
Protocol reference
Consult the official Model Context Protocol transport and tools specifications for wire formats. The integration here intentionally exposes discovery only.