Gateway model discovery for ANTHROPIC_BASE

What

When ANTHROPIC_BASE_URL is set against a first-party gateway, Claude Code now discovers the gateway's available Claude/Anthropic models on startup and lists them in the model picker labelled From gateway.

Details

On startup it issues GET <baseUrl>/v1/models?limit=1000 (using whichever of ANTHROPIC_AUTH_TOKEN / API key is configured plus any ANTHROPIC_CUSTOM_HEADERS), filters to entries whose id starts with claude or anthropic, and caches them in <config-dir>/cache/gateway-models.json keyed by base URL.
Empty / non-OK responses are dropped with debug logs: [gatewayDiscovery] non-OK status …, [gatewayDiscovery] response body failed validation, [gatewayDiscovery] 0 usable models after filter, [gatewayDiscovery] cached N models.
Discovery is skipped when the host manages the provider (CLAUDE_CODE_PROVIDER_MANAGED_BY_HOST) or when not in first-party mode.
The /model picker merges these into the available list so Bedrock/Vertex-only models get inline labels and descriptions instead of being hidden.

Evidence

Gateway discovery (search for "gateway-models.json", "/v1/models?limit=1000", and "From gateway").

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

See this entry in the whole of v2.1.124 →

The build it came inv2.1.124

30 Apr 2026 · 38 entries, this one is #4.

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v2.1.126Newer

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Names in this entry

envANTHROPIC_BASE_URL
Override the API endpoint to route requests through a proxy or gateway. When set to a non-first-party host, MCP tool search is disabled by default. Set ENABLE_TOOL_SEARCH=true if your proxy forwards tool_reference blocks. As of v2.1.196, Remote Control is disabled when this points at a host other than api.anthropic.com, matching its behavior on Amazon Bedrock, Google Cloud's Agent Platform, and Microsoft Foundry
envANTHROPIC_AUTH_TOKEN
Custom value for the Authorization header (the value you set here will be prefixed with Bearer )
envANTHROPIC_CUSTOM_HEADERS
Custom headers to add to requests (Name: Value format, newline-separated for multiple headers). If a name or value contains a character an HTTP header can't carry, such as a curly quote or a zero-width space, the request fails with an error that identifies the pair by position. Requires Claude Code v2.1.227 or later. Invalid request header value lists the exact character set and where the check runs. A value that sets a credential, org or tenant, routing, or API-behavior header, such as Authorization or Host, counts as a setting that needs approval when server-managed settings deliver it. From project or local settings, such a value follows the rules for when env values apply
envCLAUDE_CODE_PROVIDER_MANAGED_BY_HOST
Setting CLAUDE_CODE_PROVIDER_MANAGED_BY_HOST makes the parent process dictate your model settings, ignoring your settings file.
slash/model
Switch the AI model and save it as your default for new sessions. For models that support it, use left/right arrows to adjust effort level. With no argument, opens a picker; press s on a row to switch for the current session only. See when Claude Code asks you to confirm the switch. Once you confirm the switch, if Claude Code asks, Claude Code applies the change without waiting for the current response to finish. Before v2.1.242, Claude Code decided from a feature flag it fetched from Anthropic whether to run the command mid-turn or queue it until the turn finished, and always queued it in a session that doesn't fetch feature flags, such as on a third-party provider. Also available in non-interactive mode (-p) with a model argument instead of the picker, where it applies to the current session only and isn't saved as your default; requires Claude Code v2.1.205 or later

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