0007. MCP is a thin layer over the API

• Status: accepted
• Date: 2026-10-15
• Decided by: Ulf (maintainer)

Context

Part of the standalone goal (ADR 0001) is that outside tools, including AI agents, can use the app through a standard surface.

Options considered

Not recorded. The plan named an MCP server as a thin layer over the same functions as the API and CLI.

Recommendation at the time: thin layer over the same functions.

Decision

The MCP server is a thin layer over the API's functions. Write tools are available only when the server runs with --allow-write and the caller's token has write scope.

Consequences

• 27 read tools and 8 resources are always available; 22 write tools only when enabled.
• Transports: stdio, and Streamable HTTP at /mcp with a bearer check.
• No separate business logic to keep in step with the API.

Links

docs/brickwork/api-v1.md section 7. Related: ADR 0001, 0003.