mcp-proxy

The MCP Proxy itself demonstrates robust implementation for its core functionality and configurable security features. It supports API key authentication via `X-API-Key` headers and custom stateless OAuth 2.0 JWT Bearer token authentication through a user-provided callback. HTTPS/SSL is supported for encrypted communication. CORS is configurable with sensible defaults, allowing users to fine-tune origin, methods, and headers. The `/ping` and `OPTIONS` endpoints are exempt from authentication. However, as a proxy, its overall security posture heavily depends on the trustworthiness and security of the underlying MCP server it spawns and communicates with over stdio. The use of `child_process.spawn` (especially with the `--shell` option) means that executing untrusted commands via the proxy could lead to arbitrary code execution on the host. The `--tunnel` feature, while convenient, exposes the local server to the public internet, requiring careful consideration of the proxied application's vulnerabilities. No obvious hardcoded secrets, `eval` usage on untrusted input, or malicious patterns were found within the proxy's source code itself.