FastAPI MCP-Style Server
Minimal FastAPI implementation that mimics a subset of Model Context Protocol (MCP) functionality.
Features
- Echo-style POST
/mcpendpoint returning structured response (id, status, outputs) - JSON-RPC 2.0 endpoint
/mcp/rpcsupporting:mcp.list_toolsmcp.call_tool(tools:echo,uppercase,query_manse,calc_daewoon)
- GET usage helper
/mcp - Pydantic models for request/response
- Basic logging
- Tests (pytest) for REST + RPC
Quick Start
python -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt
uvicorn main:app --reload
REST Usage
curl -X POST http://127.0.0.1:8000/mcp \
-H 'Content-Type: application/json' \
-d '{"inputs": {"text": "hello"}}'
JSON-RPC Examples
List tools:
curl -X POST http://127.0.0.1:8000/mcp/rpc \
-H 'Content-Type: application/json' \
-d '{"jsonrpc":"2.0","id":1,"method":"mcp.list_tools"}'
Call echo:
curl -X POST http://127.0.0.1:8000/mcp/rpc \
-H 'Content-Type: application/json' \
-d '{"jsonrpc":"2.0","id":"abc","method":"mcp.call_tool","params":{"name":"echo","arguments":{"text":"hello"}}}'
Call query_manse (first 5 rows):
curl -X POST http://127.0.0.1:8000/mcp/rpc \
-H 'Content-Type: application/json' \
-d '{"jsonrpc":"2.0","id":2,"method":"mcp.call_tool","params":{"name":"query_manse","arguments":{"limit":5}}}'
Call calc_daewoon (example date):
curl -X POST http://127.0.0.1:8000/mcp/rpc \
-H 'Content-Type: application/json' \
-d '{"jsonrpc":"2.0","id":3,"method":"mcp.call_tool","params":{"name":"calc_daewoon","arguments":{"yyyymmdd":"20250115"}}}'
Response example:
{
"jsonrpc": "2.0",
"id": 3,
"result": {
"outputs": [
{"type": "json", "content": {"asc_diff_days": 3, "desc_diff_days": 2}}
]
}
}
Meaning:
- asc_diff_days: 기준일 이후 다음 절기까지 (일수 / 3 반올림)
- desc_diff_days: 기준일 이전 직전 절기까지 (일수 / 3 반올림)
- 없으면 null
Environment Variables (DB)
| Variable | Default | Description |
|---|---|---|
| MCP_DB_HOST | 192.168.31.136 | MariaDB host |
| MCP_DB_PORT | 3306 | MariaDB port |
| MCP_DB_USER | DB user | |
| MCP_DB_PASSWORD | DB password | |
| MCP_DB_NAME | manse | Database name |
Example run with overrides:
MCP_DB_HOST=127.0.0.1 MCP_DB_USER=app MCP_DB_PASSWORD=secret uvicorn main:app --reload
Run Tests
pytest -q
Next Ideas
- Streaming (SSE) outputs
- Prompts/resources primitives
- Auth layer (OAuth / API key)
- Tool change events