We are performing maintenance on our Optimism RPC archive nodes. During this maintenance, Optimism RPC requests sent without an API key will fail with an error.
Requests sent with an API key are not affected, and this includes free API keys. If you use Optimism RPC without a key, you can create a free API key at https://app.pinax.network to keep working during the maintenance.
We will post an update when keyless access to Optimism RPC is restored.