What probably matters to youSection of the release
What
Telemetry export now decides per signal (metrics, logs, traces) whether to send OTLP data to a gateway endpoint derived from ANTHROPIC_BASE_URL, authenticated with a Bearer header from ANTHROPIC_AUTH_TOKEN. It only does this when CLAUDE_CODE_PROVIDER_MANAGED_BY_HOST is set, the auth mode is first-party/gateway, the token is scoped to the gateway audience, you have set no OTLP headers of your own, and your OTLP endpoint already matches the derived URL. Any other combination sends nothing.
Details
The check runs separately for each signal, so metrics can qualify while traces do not.
User-set OTEL_EXPORTER_OTLP_* headers disqualify the signal outright, so your own collector configuration is never overridden.
Falls back to returning "do not send" rather than erroring.
Evidence
claude-gateway
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
The entry above is what we published on the day. These lines were added later, as Anthropic's own pages caught up, and they sit beside the original rather than replacing it.
Confirmed sinceAnthropic's documentation has since written up ANTHROPIC_AUTH_TOKEN, on Connect Claude Code to an LLM gateway.* **Amazon Bedrock, Google Cloud's Agent Platform, or Claude Platform on AWS**: add `ANTHROPIC_AUTH_TOKEN` after the block. Claude Code sends it to the gateway as an `Authorization: Bearer` header. For a credential in a different scheme or…llm-gateway-connectsee the edit
Confirmed sinceAnthropic's documentation has since written up ANTHROPIC_BASE_URL, on Claude Code changelog.* Fixed every turn failing with HTTP 400 on third-party Anthropic-compatible endpoints (`ANTHROPIC_BASE_URL`) since 2.1.265: a regex in the Artifact tool's input schema that those endpoints rejectchangelogsee the edit
How sure we are
Two sources agreeTwo things we can check say the same as this entry.
Anthropic's documentation agreesAnthropic's documentation has since written up ANTHROPIC_BASE_URL, on Claude Code changelog.
Anthropic's release notes agreeFixed /model rejecting Sonnet/Opus 1M for claude.ai subscribers using a custom ANTHROPIC_BASE_URL gateway
