/v1/messages alongside its OpenAI-compatible endpoints, so Anthropic-format
tooling talks to it directly. That covers the Anthropic SDKs, the Claude Agent SDK, and
Claude Code.
What you need
BASE_URL— your Impala endpointAPI_KEY— your Impala keyMODEL— the model your endpoint serves
Authorization: Bearer or x-api-key is accepted, so the SDKs work with their own
defaults.
The Anthropic SDKs append
/v1/messages to whatever base URL you give them. Pass the host root,
not a URL that already ends in /v1.Anthropic SDK
Claude Agent SDK and Claude Code
Both read the standard Anthropic environment variables, so neither needs a code change:claude, from that same shell.
Set ANTHROPIC_MODEL explicitly. Clients that discover available models at startup expect
Anthropic’s own catalog, and naming the model yourself avoids that lookup.

