Because the whole configuration is a key, swapping which hosted server your client talks to is a one-line change rather than a new install — and nothing runs on your machine except the relay. The corollary is that the hosted side owns availability and whatever credentials that server needs, so this is a convenience layer rather than an isolation layer.
A proxy. It runs locally over stdio and forwards to a server hosted on MCP.so, so a client that only speaks stdio can use a remote server without you deploying anything.
- Whatever the hosted server exposes appears in your client — the proxy relays the tool list and the calls; you choose which server by the key you configure
The npm package mcprouter, version 0.1.7, run through npx with SERVER_KEY set. The key comes from mcp.so: pick a hosting server there and click Connect to generate one that is yours.
One command plus a key — npx -y mcprouter, then supply credentials