Mock OAuth2 MCP Server

A lightweight mock server that combines an OAuth2 token endpoint with an MCP (Model Context Protocol) Streamable HTTP endpoint. Built for testing OAuth2 client_credentials (M2M) flows with LiteLLM proxy.

Features

• OAuth2 token endpoint (POST /oauth/token) — issues bearer tokens via the client_credentials grant
• MCP endpoint (POST /mcp) — Streamable HTTP transport with a built-in echo tool
• Bearer token validation — the MCP endpoint rejects requests without a valid token

Quick Start

pip install fastapi uvicorn

python mock_oauth2_mcp_server.py

The server starts on port 8765.

Test Credentials

Parameter	Value
client_id	test-client
client_secret	test-secret

LiteLLM Config

Add the following to your LiteLLM proxy config YAML:

mcp_servers:
  test_oauth2_server:
    url: "http://localhost:8765/mcp"
    transport: "http"
    auth_type: "oauth2"
    client_id: "test-client"
    client_secret: "test-secret"
    token_url: "http://localhost:8765/oauth/token"

Documentation

See the full LiteLLM MCP OAuth docs: https://docs.litellm.ai/docs/mcp_oauth