MCPProxy

The MCP SSE Proxy Server acts as a bridge that lets any application—whether it’s a browser automation tool, a database client, or an AI‑powered development environment—talk to Model Context Protocol (MCP) servers over the web. By exposing MCP via Server‑Sent Events, it keeps a single, long‑lived HTTP connection open for each client. This eliminates the need for polling or WebSocket workarounds, ensuring that context updates and tool responses flow smoothly from the server to the AI assistant in real time.

For developers, this means they can spin up complex MCP back‑ends (for example, a file‑system navigator or a data‑fetching tool) and expose them to Claude or other LLM assistants without writing custom adapters. The proxy handles the MCP handshake, message framing in JSON‑RPC 2.0, and error reporting automatically. It also offers two session modes: shared for collaborative workflows where many assistants share the same context, and independent so each client gets its own isolated MCP session. This flexibility is crucial for scaling from single‑user prototypes to multi‑tenant services.

Key capabilities include:

• SSE long‑connection support that guarantees low‑latency push notifications from the MCP server to clients.
• Automatic 30‑second heartbeats keep the connection alive through firewalls and load balancers.
• Dynamic environment configuration via request parameters, letting users tweak the MCP server’s behavior on the fly.
• Built‑in process deployment with NPX and UVX, so a new MCP instance can be launched from a simple command string.
• Extensible routing that allows multiple underlying MCP servers to be served from the same proxy, with custom logic for load balancing or user‑specific routing.

Real‑world scenarios that benefit from this proxy include: a web‑based IDE where the assistant can read and write code files through an MCP server; an e‑commerce chatbot that pulls inventory data via a database MCP; or a research assistant that interacts with large language models and external knowledge bases simultaneously. In each case, the proxy removes the plumbing overhead, letting developers focus on building the core tool logic while trusting MCP to handle context exchange reliably.