Use Haiku 4.5 For Subagents instead of Haiku 3.5

[luisxcosta]

Hey,

currently I'm defining one of my subagents like this:

    "subagent": AgentDefinition(
        description="foo",
        tools=tools
        prompt="bar",
        model="haiku",
    ),

And from the traces I noticed that this uses claude-3-5-haiku-20241022. Would it be possible to allow using haiku 4.5 here instead?

Thanks!

[goudete]

This would be super helpful 🙏

[ashwin-ant]

Which API provider are you on? Are you on Bedrock or Vertex by any chance? On Bedrock and vertex the default Haiku model is currently 3.5 but this is overridable via the ANTHROPIC_DEFAULT_HAIKU_MODEL env var. Try setting it to us.anthropic.claude-haiku-4-5-20251001-v1:0 for Bedrock or claude-haiku-4-5@20251001 for Vertex.

[luisxcosta]

Ah - thank you @ashwin-ant ! We're on Vertex.

[ashwin-ant]

Please reopen if you still have issues after setting the env var!