Environment Variables
SettingMODEL_NAME=anthropic/claude-3-5-sonnet is enough — no need to set OPENAI_BASE_URL. The ANTHROPIC_API_KEY environment variable is consulted; OPENAI_API_KEY is not used as a fallback.
If you just want the Anthropic default, setting ANTHROPIC_API_KEY alone is enough — no MODEL_NAME, no llm=. Agent(...) picks anthropic/claude-3-5-sonnet-latest and routes it through litellm. See Provider Auto-Detection.
Models
- Recommended:
claude-3-5-sonnet-20241022(best balance) - Fast/Cheap:
claude-3-5-haiku-20241022(fastest, affordable) - Advanced:
claude-3-opus-20240229(highest capability) - Latest:
claude-sonnet-4-5,claude-haiku-4-5(newest)
Routed model formats
Claude reached through Bedrock, Vertex AI, or OpenRouter is now detected as Anthropic — not misrouted to the OpenAI adapter — so async streaming works for these prefixes too.
See Routed model provider detection for the full detection rules.

