A gateway that teaches your old API to speak MCP

What it does Unla is a gateway that sits between MCP clients and your existing infrastructure. It converts RESTful APIs into MCP-compliant endpoints and can proxy traffic to existing MCP servers, all driven by YAML configuration instead of code changes. It handles SSE and Streamable HTTP transports, supports multi-tenancy, and persists sessions and configuration to disk or a database.

The interesting bit The project treats protocol translation as an infrastructure layer rather than a development task. It bundles a management UI, supports configuration hot-reloading over Redis PubSub or OS signals, and is designed for multi-replica deployments—behaving more like a production API gateway than a local dev adapter.

Key highlights

• Converts REST APIs to MCP servers via YAML; also proxies existing MCP servers
• Supports SSE and Streamable HTTP with persistent, recoverable sessions
• Configuration hot-reloading with persistence to SQLite, PostgreSQL, or MySQL
• Built-in web UI and OAuth pre-authentication layer for MCP servers
• Docker and Kubernetes/Helm ready with multi-replica support

Caveats

• The authors warn that backward compatibility is not guaranteed during upgrades because the project is evolving quickly, and documentation sometimes lags behind releases
• gRPC and WebSocket conversion are on the roadmap but not yet implemented
• Grouping and aggregating multiple MCP servers is also listed as a pending feature

Verdict Evaluate it if you need to bridge existing REST infrastructure into an MCP ecosystem without rewriting services. Skip it if you need gRPC or WebSocket translation today, or if you require guaranteed stable APIs before a v1.0 release.