Running several OAuth-protected MCP servers means several token lifecycles, and expiry is the failure that shows up as an agent silently losing a capability. Centralising that in a gateway means one key in your client and refreshes handled elsewhere. The trade is architectural: your tool calls go through a third party's inference path, which is a different trust decision from connecting a client directly to a vendor.
FastRouter puts the MCP layer inside its chat completions API. There is no standalone MCP URL to add to a client — you call the gateway, and it reaches the tool servers configured behind it.
Whatever tool servers you have configured in the gateway. Each can have its own authentication: none, a static header, or OAuth 2.0 with automatic refresh.
A FastRouter API key. Per-server credentials are configured on their side, so your client holds one key rather than one per tool server.
Paste a URL, then authorize — add the endpoint to your client, then approve the OAuth consent screen