AIgateway now speaks the Anthropic Messages API natively, so the official `anthropic` SDK works unchanged. Point its base URL at AIgateway, use your sk-aig- key, and call client.messages.create as you always have. Pass a bare Claude name to run on Claude, or any AIgateway slug to run the Anthropic SDK on any model in the catalog.
Point base_url at AIgateway's /anthropic path and use your sk-aig- key. The SDK sends it as x-api-key automatically; the gateway accepts it.
Same swap on the JS side, via the @anthropic-ai/sdk package.