hawkapi-mcp

MCP (Model Context Protocol) server for HawkAPI. Auto-exports every route as an agent tool — any MCP-compatible client can call your API.

Install

pip install hawkapi-mcp

Quickstart

from hawkapi import HawkAPI
from hawkapi.responses import JSONResponse
from hawkapi_mcp import mount_mcp

app = HawkAPI()

@app.get("/users/{user_id:int}")
async def get_user(user_id: int) -> JSONResponse:
    return JSONResponse({"id": user_id, "name": "Alice"})

@app.post("/items")
async def create_item(body: dict) -> JSONResponse:
    return JSONResponse({"created": body})

mount_mcp(app, allow_unauthenticated=True)  # serves POST /mcp — dev only; see Auth

/mcp MUST be protected in production — pass dependencies=[...] to require auth, or allow_unauthenticated=True to opt out explicitly. See Auth.

Point any MCP-compatible client at http://your-host/mcp. Every HawkAPI route becomes a tool — its operationId is the tool name, the OpenAPI schema becomes the input schema.

Tool naming

Tool input schema

The decorator combines path / query / header parameters and the JSON request body into a single object schema. Parameter names are namespaced so they cannot collide:

Cookie parameters are deliberately not exposed as tool inputs — exposing session cookies as data trains agents to handle credentials as ordinary fields. Forward credentials via the request to /mcp instead (see Auth).

tools/call example:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "get_user",
    "arguments": {"path.user_id": "42"}
  }
}

The tool result has the response body in content[0].text and the raw HTTP status / headers in structuredContent. isError is true for any 4xx/5xx response.

Credential-bearing response headers are stripped from structuredContent before the agent sees them: set-cookie, authorization, and anything matching x-*-token / x-*-secret. Add more via strip_response_headers={...}.

Filtering tools

mount_mcp(app, include_only={"get_user", "create_item"})
mount_mcp(app, exclude={"internal_admin_route"})

Supported JSON-RPC methods

• initialize — handshake. Returns the MCP protocol version, server info, and tool capability.
• ping — keepalive.
• tools/list — return the tool catalog.
• tools/call — invoke a tool. Returns response body + HTTP status.
• notifications/initialized — accepted, no response.

The endpoint accepts both single JSON-RPC objects and batches.

Auth

The /mcp endpoint exposes every route and MUST be protected. A single MCP tool call can invoke any route, and the bridge synthesises an inner ASGI request — so middleware that only guards inner routes can be bypassed. To make this hard to get wrong, mount_mcp() raises RuntimeError at mount time unless you either:

• pass dependencies=[...] to attach auth (e.g. Depends) to the /mcp route, or
• explicitly opt out with allow_unauthenticated=True (local dev, or auth enforced upstream).

from hawkapi import Depends
from hawkapi_mcp import mount_mcp

mount_mcp(app, dependencies=[Depends(verify_token)])  # protected
mount_mcp(app, allow_unauthenticated=True)            # explicit opt-out

hawkapi-mcp does not define its own auth layer — wire your HawkAPI dependencies (HTTPBearer, OAuth2, API key) on the MCP route just like any other path. The caller's Authorization and Cookie headers on the outer /mcp request are forwarded into the synthetic inner request, so inner-route Depends(auth) sees the real credentials (and the real client address is propagated where available). Header arguments forwarded by the client land in the request before middleware runs.

Tool catalog freshness

The tool catalog is derived from app.openapi() and cached. By default it is cached for the process lifetime, so routes added/removed/disabled at runtime are not reflected — call server.invalidate_tools() to force a refresh, or pass cache_ttl_seconds=... to mount_mcp() (or MCPServer) to auto-refresh after the given interval:

mount_mcp(app, dependencies=[...], cache_ttl_seconds=60)

Development

git clone https://github.com/Hawk-API/hawkapi-mcp.git
cd hawkapi-mcp
uv sync --extra dev
uv run pytest -q
uv run ruff check . && uv run ruff format --check .
uv run pyright src/

Specification

Implements a subset of the Model Context Protocol sufficient to advertise and invoke tools. Streamable HTTP transport only — stdio is out of scope (deploy your app behind any ASGI server and the agent connects to the /mcp URL).

License

MIT.