Truto MCP Stdio Proxy

A CLI program that bridges stdio-based MCP clients to HTTP Streamable MCP servers. It reads newline-delimited JSON-RPC messages from stdin, forwards them to a specified MCP server endpoint via HTTP POST, handles SSE streaming responses, and writes the responses to stdout.

Implements the MCP Streamable HTTP transport (spec version 2025-11-25).

Features

• Streamable HTTP transport -- full support for both application/json and text/event-stream responses
• Session management -- automatically tracks MCP-Session-Id across requests
• Protocol version negotiation -- extracts protocolVersion from the initialize handshake and sends MCP-Protocol-Version on subsequent requests
• Server-initiated messages -- opens a background GET SSE stream for server-to-client notifications and requests, with automatic reconnection
• Session cleanup -- sends HTTP DELETE on shutdown to cleanly terminate the session

Requirements

• Go 1.24.2 or later (for building from source)

Installation

Download Pre-built Binaries

Download the latest release from the GitHub releases page. Choose the appropriate binary for your platform:

• Linux (amd64): truto-mcp-stdio-linux-amd64-v<version>
• macOS (Intel): truto-mcp-stdio-darwin-amd64-v<version>
• macOS (Apple Silicon): truto-mcp-stdio-darwin-arm64-v<version>
• Windows (amd64): truto-mcp-stdio-windows-amd64-v<version>.exe

After downloading, make the binary executable (on Unix-like systems):

chmod +x truto-mcp-stdio-<platform>-v<version>

Building from Source

go build -o truto-mcp-stdio

Usage

./truto-mcp-stdio <API_URL>

Arguments

• <API_URL>: The MCP server HTTP endpoint URL (required)

Example

echo '{"jsonrpc": "2.0", "method": "initialize", "params": {"protocolVersion": "2025-11-25", "capabilities": {}, "clientInfo": {"name": "test", "version": "1.0.0"}}, "id": 1}' | ./truto-mcp-stdio https://api.truto.one/mcp/<your-mcp-id>

Client Setup

Below are setup instructions for all major MCP clients. Replace /path/to/truto-mcp-stdio with the actual path to the binary and <your-mcp-id> with your Truto MCP endpoint ID.

Cursor

Config file: ~/.cursor/mcp.json (global) or .cursor/mcp.json (project-scoped)

{
  "mcpServers": {
    "truto": {
      "command": "/path/to/truto-mcp-stdio",
      "args": ["https://api.truto.one/mcp/<your-mcp-id>"]
    }
  }
}

Cursor hot-reloads config changes -- no restart needed.

Claude Desktop

Config file locations:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\\Claude\\claude_desktop_config.json

{
  "mcpServers": {
    "truto": {
      "command": "/path/to/truto-mcp-stdio",
      "args": ["https://api.truto.one/mcp/<your-mcp-id>"]
    }
  }
}

Requires a full restart of Claude Desktop after editing.

Claude Code (CLI)

Add via the CLI:

claude mcp add truto -- /path/to/truto-mcp-stdio https://api.truto.one/mcp/<your-mcp-id>

Or create .mcp.json at your project root:

{
  "mcpServers": {
    "truto": {
      "type": "stdio",
      "command": "/path/to/truto-mcp-stdio",
      "args": ["https://api.truto.one/mcp/<your-mcp-id>"]
    }
  }
}

VS Code (GitHub Copilot)

Create .vscode/mcp.json in your project:

{
  "servers": {
    "truto": {
      "type": "stdio",
      "command": "/path/to/truto-mcp-stdio",
      "args": ["https://api.truto.one/mcp/<your-mcp-id>"]
    }
  }
}

Note: VS Code uses "servers" as the root key, not "mcpServers".

Windsurf

Config file locations:

• macOS/Linux: ~/.codeium/windsurf/mcp_config.json
• Windows: %USERPROFILE%\\.codeium\\windsurf\\mcp_config.json

{
  "mcpServers": {
    "truto": {
      "command": "/path/to/truto-mcp-stdio",
      "args": ["https://api.truto.one/mcp/<your-mcp-id>"]
    }
  }
}

Requires a restart of Windsurf after editing.

Cline (VS Code Extension)

Add via the MCP Servers panel in the Cline sidebar, or edit the config file directly:

• macOS: ~/Library/Application Support/Code/User/globalStorage/saoudrizwan.claude-dev/settings/cline_mcp_settings.json
• Windows: %APPDATA%\\Code\\User\\globalStorage\\saoudrizwan.claude-dev\\settings\\cline_mcp_settings.json

{
  "mcpServers": {
    "truto": {
      "command": "/path/to/truto-mcp-stdio",
      "args": ["https://api.truto.one/mcp/<your-mcp-id>"]
    }
  }
}

Development

go run truto-mcp-stdio.go <API_URL>

How It Works

1. Reads JSON-RPC messages line-by-line from stdin
2. Sends each message as an HTTP POST to the MCP endpoint with the required Accept, MCP-Session-Id, and MCP-Protocol-Version headers
3. Handles responses in both application/json and text/event-stream (SSE) formats
4. Extracts MCP-Session-Id from the server's initialize response and includes it on all subsequent requests
5. Extracts the negotiated protocolVersion and sends it as the MCP-Protocol-Version header
6. Opens a background GET SSE stream after initialization for server-initiated messages, with automatic reconnection
7. On shutdown (stdin close or signal), sends HTTP DELETE to cleanly terminate the session
8. Errors and diagnostics are written to stderr