rust-mcp-remote

A Rust port of mcp-remote. It lets an MCP client that only speaks stdio, such as Claude Desktop, Cursor or Windsurf, use a remote MCP server over Streamable HTTP or SSE, including servers that need an OAuth sign-in.

It is a single binary with no Node.js. It accepts the same flags as mcp-remote and keeps its sign-in files in the same folder, so it can replace npx mcp-remote in an existing config.

Install

You need Rust.

cargo install --locked --force --git https://github.com/ravshansbox/rust-mcp-remote

This puts rust-mcp-remote and mcp-remote-client in ~/.cargo/bin. --force makes cargo rebuild even if this version is already installed, so the same command also upgrades or reinstalls.

Upgrade or reinstall: run the cargo install command again.

Uninstall:

cargo uninstall rust-mcp-remote
rm -r ~/.mcp-auth/mcp-remote-v1          # optional: tokens, client registrations and logs

~/.mcp-auth/mcp-remote-v1 is shared with npm mcp-remote, so leave it if you still use that.

Usage

Point your MCP client at the binary. MCP clients usually start servers without your shell's PATH, so use the full path:

{
  "mcpServers": {
    "remote-example": {
      "command": "/Users/you/.cargo/bin/rust-mcp-remote",
      "args": ["https://remote.mcp.server/mcp"]
    }
  }
}

On first use it opens your browser to sign in, and saves the tokens to ~/.mcp-auth/mcp-remote-v1/. Later runs reuse and renew them. If several copies start at once for the same server, one signs in and the others wait for its tokens.

To try a server from a terminal, mcp-remote-client signs in, lists the server's tools and resources, and exits:

mcp-remote-client https://remote.mcp.server/mcp

Show help with --help and the version with --version.

Flags

Put flags after the server URL. A number after the URL sets the OAuth callback port. Without it, the port comes from the server URL, so every server gets a stable port of its own.

Flag	What it does
--header "Name: value"	Send a header with every request. Repeat for more
--header-file <path>	Read Name: value lines from a file
--transport <strategy>	http-first (default), sse-first, http-only or sse-only
--protocol <mode>	legacy (default) or auto, which also bridges to 2026-07-28 servers
--allow-http	Allow a plain HTTP server URL, for trusted private networks
--host <name>	Host in the OAuth callback URL (default localhost)
--callback-path <path>	Path of the OAuth callback (default /oauth/callback)
--auth-timeout <seconds>	How long to wait for the OAuth callback (default 30)
--resource <url>	The resource to ask a token for
--disable-resource-parameter	Leave resource out of OAuth requests
--authorize-param key=value	Add a parameter to the authorization request
--static-oauth-client-metadata <json or @file>	Client metadata to register with
--static-oauth-client-info <json or @file>	A pre-registered client, instead of registering one
--client-metadata-url <https url>	Use a Client ID Metadata Document as the client ID
--use-id-token	Send the ID token instead of the access token
--device-code	Sign in with the device grant, without a browser on this machine
--client-credentials	Sign in with the client credentials grant, without a user
--token-endpoint <https url>	Token endpoint for --client-credentials, skipping discovery
--ignore-tool <pattern>	Hide matching tools and block calls to them. * is a wildcard. Repeat for more
--keep-alive	Ping the server every 30 seconds so an idle session is not dropped
--ping-interval <seconds>	Ping period. Turns on keep-alive
--connect-timeout <seconds>	Limit on opening a connection
--headers-timeout <seconds>	Limit on waiting for response headers. 0 turns it off
--body-timeout <seconds>	Limit on a gap in a response body. 0 turns it off
--ipv4	Connect over IPv4 only
--enable-proxy	Use the HTTP_PROXY, HTTPS_PROXY and NO_PROXY environment variables
--disable-cookies	Do not keep or send cookies the server sets
--debug	Write a detailed log to ~/.mcp-auth/mcp-remote-v1/<hash>_debug.log
--silent	Print no log lines, except with --debug

${VAR} in a header value or in --static-oauth-client-info is replaced with the environment variable, so secrets can stay out of the config:

"args": ["https://remote.mcp.server/mcp", "--header", "Authorization: Bearer ${AUTH_TOKEN}"],
"env": { "AUTH_TOKEN": "..." }

The mcp-remote README explains each flag in more detail. Everything there applies here, with npx mcp-remote replaced by the binary.

Environment variables

Variable	What it does
MCP_REMOTE_CONFIG_DIR	Folder for tokens and logs, instead of ~/.mcp-auth
NODE_EXTRA_CA_CERTS	A PEM file of extra certificates to trust, for example a VPN's. The name is kept from mcp-remote

Differences from mcp-remote

• No default network timeouts. mcp-remote gives up after 10 seconds when connecting, and after 300 seconds waiting for headers or between body chunks. Here, each limit applies only when you set its flag.

• --connect-timeout, --headers-timeout, --body-timeout, --ipv4 and --enable-proxy apply to every request. In mcp-remote, some discovery requests ignore them.

• Certificates come from the system trust store plus NODE_EXTRA_CA_CERTS.

• Less memory. Proxying the GitHub MCP server (https://api.githubcopilot.com/mcp) on macOS, idle after initialize and tools/list:

  Command	Resident memory
  rust-mcp-remote	16 MiB
  node running mcp-remote 0.14.3 (Node.js 24)	130 MiB
  npx -y mcp-remote (adds the npm exec process)	248 MiB

  A client config with five servers uses about 80 MiB instead of about 1.2 GiB.

Limits

• Tested on macOS only. Linux and Windows, including opening the browser on Windows, are untested.

Development

Before each commit, run cargo fmt --check, cargo clippy --all-targets -- -D warnings and cargo test. Each source module has one test binary in tests/<module>/.

Licence

MIT. See LICENSE.