Structured Outputs with stream=True

Pass stream=True to receive the validated result through the Agent streaming interface.

Code

from agno.agent import Agent
from agno.models.anthropic import Claude
from pydantic import BaseModel


class TravelPlan(BaseModel):
    destination: str
    days: int
    activities: list[str]


structured_output_agent = Agent(
    model=Claude(id="claude-sonnet-4-6"),
    description="You create concise travel plans.",
    output_schema=TravelPlan,
)

if __name__ == "__main__":
    structured_output_agent.print_response(
        "Plan a three-day trip to Kyoto.",
        stream=True,
    )

Agno sets stream_model_response=False when an Agent has output_schema, parse_response=True, and no parser model. Claude completes one non-streaming request. Agno validates it and then emits one TravelPlan result through the Agent streaming interface. Use a standard run() for direct access to the validated object.

This buffered path has the same model, schema, refusal, max_tokens, citation, and message-prefill constraints as non-streaming structured output.

Usage

Set up your virtual environment

uv venv --python 3.12
source .venv/bin/activate

Install dependencies

uv pip install -U "agno[anthropic]"

Export your Anthropic API key

export ANTHROPIC_API_KEY="your_anthropic_api_key_here"

Run the agent

Save the code above as structured_output_stream.py, then run:

python structured_output_stream.py