One gateway to federate MCP, A2A, and legacy APIs

What it does ContextForge is an open-source registry and proxy that federates MCP servers, A2A agents, and REST or gRPC APIs behind one unified endpoint. It acts as a fully compliant MCP server itself, adding centralized authentication, rate limiting, retries, and observability to your backends. The project packages this into a Python service with an admin UI, plugin system, and Redis-backed clustering.

The interesting bit The gateway virtualizes legacy REST and gRPC services as MCP-compliant tools without rewriting them, using automatic JSON Schema extraction and gRPC server reflection. It also routes agent traffic via the A2A protocol while translating between OpenAI and Anthropic conventions, acting as a protocol-agnostic middleman.

Key highlights

• Federates MCP, A2A, REST, and gRPC into a single gateway endpoint.
• Wraps non-MCP services as virtual MCP servers via gRPC reflection and REST-to-MCP adapters.
• Ships with 40+ plugins for extra transports and integrations.
• Built-in OpenTelemetry tracing for LLM-specific metrics like token usage and model performance.
• Admin UI uses HTMX and Alpine.js; supports airgapped deployments.

Verdict Worth a look if you are running multiple AI agents and tools across incompatible protocols and need centralized governance. Skip it if you are already all-in on a single protocol stack with no federation headaches.