GitHub - PortSwigger/mcp-proxy: SSE to Stdio MCP Proxy Server (original) (raw)

MCP Proxy

A Stdio MCP server which proxies an SSE MCP server.

Overview

This proxy acts as a bridge between:

• An SSE-based MCP server endpoint
• Standard input/output for MCP client communication

It enables tools that use standard I/O for communication such as Claude Desktop (as of 2025-04-01) to interact with MCP implementations through an SSE interface.

Requirements

• JDK 21 or higher
• Gradle 8.0+ (Wrapper included)

Build Jar

Testing

Run all tests

./gradlew test

Run a specific test

./gradlew test --tests "net.portswigger.TestName"