Structured Output

Use of Pydantic models for structured output with OpenRouter's Responses API.

Pass a Pydantic model as output_schema to request a JSON schema through OpenRouter's Responses API. Agno parses the result locally; check its type before using schema fields.

structured_output.py

from typing import List

from agno.agent import Agent
from agno.models.openrouter import OpenRouterResponses
from pydantic import BaseModel, Field

# ---------------------------------------------------------------------------
# Create Agent
# ---------------------------------------------------------------------------


class MovieScript(BaseModel):
    name: str = Field(..., description="Give a name to this movie")
    setting: str = Field(
        ..., description="Provide a nice setting for a blockbuster movie."
    )
    ending: str = Field(
        ...,
        description="Ending of the movie. If not available, provide a happy ending.",
    )
    genre: str = Field(
        ...,
        description="Genre of the movie. If not available, select action, thriller or romantic comedy.",
    )
    characters: List[str] = Field(..., description="Name of characters for this movie.")
    storyline: str = Field(
        ..., description="3 sentence storyline for the movie. Make it exciting!"
    )


agent = Agent(
    model=OpenRouterResponses(id="openai/gpt-oss-20b", reasoning={"enabled": True}),
    description="You write movie scripts.",
    output_schema=MovieScript,
)

response = agent.run("New York")
if isinstance(response.content, MovieScript):
    print(response.content.model_dump_json(indent=2))
else:
    print("The response did not validate as MovieScript:", response.content)

# ---------------------------------------------------------------------------
# Run Agent
# ---------------------------------------------------------------------------

if __name__ == "__main__":
    pass

Run the Example

Set up your virtual environment

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

Install dependencies

uv pip install -U agno openai

Set your OpenRouter API key

Use an account with access to the selected model's structured-output capability.

export OPENROUTER_API_KEY="your_openrouter_api_key_here"

Run the example

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

python structured_output.py

Adapted from the cookbook example.