mcp-stdio

A minimal stdio-to-HTTP gateway for MCP (Model Context Protocol) servers. One small Python package, one runtime dependency (httpx), two jobs:

• Connect an MCP client that only speaks stdio (Claude Desktop, Claude Code, …) to a remote HTTP MCP server — including the OAuth 2.1 login, token storage, and refresh.
• Publish a local stdio MCP server as a Streamable HTTP endpoint with a built-in OAuth 2.1 authorization server — multi-user, session-isolated.

Not sure which one you need? Start with Two ways to use it.

Install

# Homebrew
brew install shigechika/tap/mcp-stdio

# or PyPI
pip install mcp-stdio

# or run without installing
uvx mcp-stdio --help

30-second quickstart

Connect Claude Desktop to a remote MCP server that requires OAuth login — add this to claude_desktop_config.json:

{
  "mcpServers": {
    "my-remote-server": {
      "command": "mcp-stdio",
      "args": ["--oauth", "https://mcp.example.com/mcp"]
    }
  }
}

On first use a browser window opens for login; tokens are cached in ~/.config/mcp-stdio/tokens.json and refreshed automatically from then on.

That is the client side. To go the other direction — publish your own stdio MCP server over HTTPS — see Publish your stdio server.

Why this exists

MCP clients and servers do not always agree on transports, and OAuth details vary between implementations in ways that surface in real deployments. mcp-stdio sits in the middle and absorbs those differences: it follows the MCP spec and the OAuth RFCs closely, works around known interoperability gaps, and stays small enough to audit.

For the full feature list and standards conformance, see the README.