Artifact requests from cloud sessions can go via a gateway relay / Claude Code v2.1.234

You'll notice

Useful2 Signal4

Artifacts

Cloud sessions may route artifact calls through a gateway relay, falling back to direct calls on failure.

Feature flag

tengu_cobalt_plinth_sorrel Off by default, switched on for this account

The shipped code defaults this off, and the flag server returned on for the one account this site reads on this version. That is the reading that makes the entry above worth a second look, and it still says nothing about your account.

This account: on · anonymous baseline: on · compiled default in v2.1.234: off

Read once, for one account on one subscription tier, against v2.1.234. It isn't a statement about your account. What a flag value here can and cannot tell you

What

When Claude Code is running as a remote session, calls to claude.ai for publishing, comments and reads may now be sent through /v1/code/agent-proxy/frame on the gateway using the session's own token, instead of calling claude.ai directly with OAuth. If the relay refuses or errors, the request falls back to the direct call and that request family is skipped for a cool-off period.

Details

Requests are grouped into families (boot, publish, comments, db) by method and URL shape; each family keeps its own decline and serve windows, with failures opening roughly a five-minute fallback to direct calls.
Replies carry route: "direct" or route: "relay" plus a flag saying whether the answer really came from claude.ai, derived from an x-ccr-relay-upstream header. Every caller now checks it, so a relay-level HTTP status is no longer read as claude.ai's verdict: a database write whose relay call failed reports the outcome as unknown rather than failed, and publish failures get their own advisory.
The relay path only engages when the session is marked remote with no environment kind set, and behind the tengu_cobalt_plinth_sorrel flag, whose built-in fallback is on when the server sends no value.
Frame-specific headers matching ^x-frame-[a-z0-9-]+$ are stripped on the relay path. Retry-after on 429/503 is honoured only when the response actually came from claude.ai.
Telemetry artifact_frame_relay records relay_unavailable, relay_refused, relay_error and request_error, tagged with the family.

Evidence

artifact_frame_relay, /v1/code/agent-proxy/frame, x-ccr-relay-upstream, tengu_cobalt_plinth_sorrel, db write outcome unknown (relay HTTP

Strings lifted out of the shipped bundle, so the claim above can be checked against them.