You'll notice
Busy 503 responses from the relay now trigger a retry after the server's suggested delay instead of failing outright
What
When a request to the artifact-frame relay gets back an HTTP 503 ("service busy") response, Claude Code now checks for a Retry-After header telling it how long to wait. If that header is present, the request is routed back through the relay with that delay applied, and a new telemetry event called relay_busy is logged. Previously, this kind of 503 was simply treated as a relay error and not retried.
Why
This lets Claude Code recover automatically from a temporarily busy relay instead of surfacing it as a hard failure.