Internal MCP servers

Every team building on Claude was writing their own glue to internal systems. Auth, retry, schema, observability. Five times over, slightly differently each time.

A library of MCP servers, one per internal system, with a shared base that handles auth, rate limiting, structured errors, and OTel traces. Teams compose the ones they need. Adding a new tool means writing the resource handler, not the plumbing.

• Servers are libraries, not services.Each team runs them in-process. No extra hop, no extra failure mode, no shared infra to operate.
• Schema is enforced at the boundary.Tool inputs and outputs are Pydantic models. The LLM gets a clean schema; the caller gets typed responses.
• Observability is mandatory, not optional.Every tool call logs to OTel with the prompt hash and the tool result. Audit is for free.

The old loop was "wire up auth, write the API client, handle retries, decide on a schema for the LLM, debug it for two days." The new loop is "import the server, write the tool function, ship."