What
The optional pass that asks a custom ANTHROPIC_BASE_URL for its /v1/models list now logs a reason for every skip instead of silently doing nothing, and can authenticate with your apiKeyHelper command in addition to ANTHROPIC_AUTH_TOKEN or an API key. The helper is only run in a trusted workspace. The whole feature still requires CLAUDE_CODE_ENABLE_GATEWAY_MODEL_DISCOVERY.
Details
- Skip reasons cover nonessential traffic being disabled, unsuitable provider or base URL, and having no credential at all.
- In an untrusted workspace it logs
[gatewayDiscovery] skipped: apiKeyHelper requires workspace trust. ANTHROPIC_CUSTOM_HEADERSnow overrides the built-in Authorization, x-api-key and User-Agent headers case-insensitively, rather than being merged after them.- Errors are separated into "skipped:" and "failed:" and redacted before logging.
Evidence
[gatewayDiscovery] skipped: apiKeyHelper requires workspace trust
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.
Added since
A small documentation edit on Claude Code changelog touched a line naming ANTHROPIC_BASE_URL after this was published.
* Fixed every request failing with `400 … Input tag 'advisor_20260301'` when `ANTHROPIC_BASE_URL` points at a proxy or gateway (2.1.275 regression)changelog see the edit
Confirmed since
Anthropic's documentation has since written up CLAUDE_CODE_ENABLE_GATEWAY_MODEL_DISCOVERY, on Environment variables.
| `CLAUDE_CODE_GATEWAY_MODEL_DISCOVERY_TIMEOUT_MS` | Timeout in milliseconds for the [gateway model discovery](/docs/en/llm-gateway-protocol#model-discovery) request that `CLAUDE_CODE_ENABLE_GATEWAY_MODEL_DISCOVERY` turns on (default: `300…env-vars see the edit
Added since
A small documentation edit on Week 20 · May 11–15, 2026 touched a line naming apiKeyHelper after this was published.
<div>Remote Control, <code>/schedule</code>, claude.ai MCP connectors, and notification preferences are now disabled when <code>ANTHROPIC\_API\_KEY</code>, <code>apiKeyHelper</code>, or <code>ANTHROPIC\_AUTH\_TOKEN</code> is set, even alon…whats-new/2026-w20 see the edit
Confirmed since
Anthropic's documentation has since written up apiKeyHelper, 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
Confirmed since
Anthropic'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 rejectchangelog see the edit
Two sources agreeTwo things we can check say the same as this entry.
Anthropic's documentation agrees
Anthropic's documentation has since written up ANTHROPIC_BASE_URL, on Claude Code changelog.
Anthropic's release notes agree
Added server-managed settings diagnostics: a startup warning when the settings fail to load, and a /doctor and /status line explaining a…