Connect your provider keys
Your keys are sealed into one token here, in your browser. The gateway opens it only to serve your requests, and nothing stores the keys.
What happens to your keys
This page fetches the gateway's public key and seals your keys to it. Only that gateway can open the token, and it keeps no copy: no account, no database row. The token itself is the record.
Each request bills your own provider accounts, as it would on your machine. To revoke a token, rotate the provider key inside it; the old token then fails like any wrong key.
Rather run it yourself? The same gateway self-hosts in one command, with your keys in its own environment.