mcp-switchboard-client

The client half of mcp-switchboard.

It reads an mcp.json, spawns the local stdio MCP servers it describes, and opens a single outbound WebSocket to an mcp-switchboard-hub, multiplexing every server over that one connection. No inbound port is ever opened, so it works from behind NAT with nothing forwarded.

The client speaks no MCP itself — it is a pipe, shuttling each server's stdin/stdout across the tunnel. All MCP logic lives in the hub. That is why its only dependency is websockets.

Running

uvx mcp-switchboard-client --hub-url wss://switchboard.example.com --token "$TOKEN"

or bootstrap uvx/npx first with the installer:

curl -fsSL https://akospapp.github.io/mcp-switchboard/install.sh | sh -s -- \
  --hub-url wss://switchboard.example.com --token "$TOKEN"

mcp.json uses the familiar shape, resolved from the current directory:

{
  "mcpServers": {
    "git": { "command": "uvx", "args": ["mcp-server-git", "--repository", "."] }
  }
}

Settings can also come from MCP_SWITCHBOARD_* environment variables or a .env file (HUB_URL, TUNNEL_TOKEN, LABEL, CONFIG, …). Any value that starts with / and points at an existing regular file is read from that file, so a token can be passed as a path.

LABEL defaults to the machine's hostname and is how the hub tags this machine's tools, so consumers can tell which host a tool lives on.

See the main README for the full picture.