Under the hood
Nothing to try yet
A custom anthropic-beta header can be forwarded, but only once a gate is enabled.
Outgoing Anthropic API requests now merge in a header set from a new Cv() function, which forwards a custom anthropic-beta header from ANTHROPIC_CUSTOM_HEADERS only with its value stripped, and only when a gate is enabled; otherwise it returns an empty object. This matches the existing behavior of stripping custom Authorization headers.
Names in the bundleANTHROPIC_CUSTOM_HEADERS
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.
Added since
A small documentation edit on Configure server-managed settings touched a line naming ANTHROPIC_CUSTOM_HEADERS after this was published.
Whether [`ANTHROPIC_CUSTOM_HEADERS`](/docs/en/env-vars#variables) needs approval also depends on the delivered value. Headers that only tag requests, such as `Accept-Language`, apply without the dialog. A line that names a credential, an o…server-managed-settings see the edit
Confirmed since
Anthropic's documentation has since written up ANTHROPIC_CUSTOM_HEADERS, 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-connect see the edit
One source agreesOne thing we can check says the same as this entry.
Anthropic's documentation agrees
Anthropic's documentation has since written up ANTHROPIC_CUSTOM_HEADERS, on Connect Claude Code to an LLM gateway.