What is Mcp Proxy Rust

mcp_proxy_rust is a standalone binary designed to connect STDIO-based MCP clients to HTTP (SSE) based MCP servers, specifically compatible with the MCP servers that follow the ‘2024-11-05’ specification.

Use cases

Use cases for mcp_proxy_rust include connecting legacy applications to new MCP services, facilitating communication between different types of clients and servers in a development environment, and enabling testing of MCP server functionalities with various client implementations.

How to use

To use mcp_proxy_rust, download the appropriate binary for your operating system from the releases page. For macOS, use curl commands to download the binary for either Apple Silicon or Intel. For Linux, choose the version based on your architecture (x86 or arm64). For Windows, use the provided Powershell command to download and extract the binary.

Key features

Key features of mcp_proxy_rust include its ability to bridge STDIO-based clients with HTTP-based servers, support for the latest MCP specification, and easy installation across multiple operating systems including macOS, Linux, and Windows.

Where to use

mcp_proxy_rust can be used in environments where there is a need to connect traditional STDIO-based applications with modern HTTP-based MCP servers, such as in software development, testing, and integration scenarios.

mcp-proxy

A standalone binary for connecting STDIO based MCP clients to HTTP (SSE) based MCP servers.

Note: the proxy supports both SSE according to the 2024-11-05 as well as streamable HTTP according to the 2025-03-26 specification.
It may happen though that the connecting client does not support the version sent by the server.

Installation

The latest releases are available on the releases page.

macOS

Depending on your Mac, you can download the latest version with one of the following commands:

Apple Silicon:

curl -sL https://github.com/tidewave-ai/mcp_proxy_rust/releases/latest/download/mcp-proxy-aarch64-apple-darwin.tar.gz | tar xv

Intel:

curl -sL https://github.com/tidewave-ai/mcp_proxy_rust/releases/latest/download/mcp-proxy-x86_64-apple-darwin.tar.gz | tar xv

which will put the mcp-proxy binary in the current working directory (pwd).

Note that the binaries are not notarized, so if you download the release with the browser, you won’t be able to open it.

Alternatively, you can remove the quarantine flag with:

xattr -d com.apple.quarantine /path/to/mcp-proxy

Linux

You can download the latest release from the Releases page or with one command, depending on your architecture:

x86:

curl -sL https://github.com/tidewave-ai/mcp_proxy_rust/releases/latest/download/mcp-proxy-x86_64-unknown-linux-musl.tar.gz | tar zxv

arm64 / aarch64:

curl -sL https://github.com/tidewave-ai/mcp_proxy_rust/releases/latest/download/mcp-proxy-aarch64-unknown-linux-musl.tar.gz | tar zxv

Windows

You can download the latest release from the Releases page or with the following Powershell command:

curl.exe -L -o mcp-proxy.zip https://github.com/tidewave-ai/mcp_proxy_rust/releases/latest/download/mcp-proxy-x86_64-pc-windows-msvc.zip; Expand-Archive -Path mcp-proxy.zip -DestinationPath .

Building from scratch

The proxy is built in Rust. If you have Rust and its tools installed, the project can be built with cargo:

cargo build --release

Then, the binary will be located at target/release/mcp-proxy.

Usage

If you have an SSE MCP server available at http://localhost:4000/tidewave/mcp, a client like Claude Desktop would then be configured as follows.

On macos/Linux

{
  "mcpServers": {
    "my-server": {
      "command": "/path/to/mcp-proxy",
      "args": [
        "http://localhost:4000/tidewave/mcp"
      ]
    }
  }
}

On Windows

{
  "mcpServers": {
    "my-server": {
      "command": "c:\\path\\to\\mcp-proxy.exe",
      "args": [
        "http://localhost:4000/tidewave/mcp"
      ]
    }
  }
}

Configuration

mcp-proxy either accepts the SSE URL as argument or using the environment variable SSE_URL. For debugging purposes, you can also pass --debug, which will log debug messages on stderr.

Other supported flags:

• --max-disconnected-time the maximum amount of time for trying to reconnect while disconnected. When not set, defaults to infinity.
• --override-protocol-version to override the protocol version reported by the proxy. This is useful when using the proxy with a client that expects a different protocol version, when the only reason for mismatching protocols is the use of streamable / SSE transports.