Simple HTTP MCP Server

from http import HTTPStatus from starlette.testclient import TestClient from http_mcp._transport_types import ProtocolErrorCode from tests.models import DUMMY_SERVER def test_initialize_bad_request() -> None: client = TestClient(DUMMY_SERVER.app) response = client.post( "/mcp", json={ "jsonrpc": "2.0", "id": 1, "method": "initialize", "params": { "protocolVersion": "2025-06-18", }, }, headers={"Content-Type": "application/json"}, ) assert response.status_code == HTTPStatus.OK assert response.json() == { "jsonrpc": "2.0", "id": 1, "error": { "code": ProtocolErrorCode.INVALID_PARAMS.value, "message": '[{"type": "missing", "loc": ["params", "clientInfo"], ' '"msg": "Field required", "input": {"protocolVersion": ' '"2025-06-18"}, "url": ' '"https://errors.pydantic.dev/2.12/v/missing"}, {"type": ' '"missing", "loc": ["params", "capabilities"], "msg": ' '"Field required", "input": {"protocolVersion": ' '"2025-06-18"}, "url": ' '"https://errors.pydantic.dev/2.12/v/missing"}]', }, } def test_initialize_unsupported_version() -> None: client = TestClient(DUMMY_SERVER.app) response = client.post( "/mcp", json={ "jsonrpc": "2.0", "id": 1, "method": "initialize", "params": { "protocolVersion": "2024-11-05", "capabilities": { "roots": { "listChanged": True, }, "sampling": {}, "elicitation": {}, }, "clientInfo": { "name": "ExampleClient", "title": "Example Client Display Name", "version": "1.0.0", }, }, }, headers={"Content-Type": "application/json"}, ) assert response.status_code == HTTPStatus.OK assert response.json() == { "jsonrpc": "2.0", "id": 1, "error": { "code": ProtocolErrorCode.INVALID_PARAMS.value, "message": "Unsupported protocol version", "data": { "supported": ["2025-03-26", "2025-06-18", "2025-11-25"], "requested": "2024-11-05", }, }, } def test_method_not_found() -> None: client = TestClient(DUMMY_SERVER.app) response = client.post( "/mcp", json={"jsonrpc": "2.0", "method": "invalid", "id": 1}, headers={"Content-Type": "application/json"}, ) assert response.status_code == HTTPStatus.BAD_REQUEST assert response.json() == { "jsonrpc": "2.0", "id": 1, "error": { "code": ProtocolErrorCode.METHOD_NOT_FOUND.value, "message": "Error validating message request", }, } def test_invalid_tool_execution_request() -> None: client = TestClient(DUMMY_SERVER.app) response = client.post( "/mcp", json={ "jsonrpc": "2.0", "method": "tools/call", "id": 1, }, headers={"Content-Type": "application/json"}, ) assert response.status_code == HTTPStatus.OK assert response.json() == { "jsonrpc": "2.0", "id": 1, "error": { "code": ProtocolErrorCode.INVALID_PARAMS.value, "message": '[{"type": "model_type", "loc": ["params"], "msg": "Input should be a ' 'valid dictionary or instance of ToolsCallRequestParams", "input": ' 'null, "ctx": {"class_name": "ToolsCallRequestParams"}, "url": ' '"https://errors.pydantic.dev/2.12/v/model_type"}]', }, }