Typed Python APIs for people and agents.

Build one route surface for HTTP and MCP tools, with explicit auth and fast msgspec serialization.

One handler, two surfaces

A route can stay a normal HTTP endpoint and, when you opt in, become an MCP tool without creating a second app path.

HTTP routes use route-level auth. MCP has a transport auth boundary, then the same route auth inside tool calls.

Quater keeps the hot path small: Granian on RSGI, msgspec for JSON, and a native router underneath.

OpenAPI, Swagger UI, and MCP tool docs are generated from the route metadata you already wrote.