Structured Output

Agno attempts to parse the response into MovieScript. If parsing fails, RunOutput.content can remain a string; check isinstance(response.content, MovieScript) before using typed fields. A completed run alone does not prove schema validation succeeded.

Code

from typing import List

from agno.agent import Agent, RunOutput  # noqa
from agno.models.langdb import LangDB
from pydantic import BaseModel, Field
from rich.pretty import pprint  # noqa

class MovieScript(BaseModel):
    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.",
    )
    name: str = Field(..., description="Give a name to this movie")
    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 that uses JSON mode
json_mode_agent = Agent(
    model=LangDB(id="llama3-1-70b-instruct-v1.0"),
    description="You write movie scripts.",
    output_schema=MovieScript,
    use_json_mode=True,
)

# Agent that uses structured outputs
structured_output_agent = Agent(
    model=LangDB(id="llama3-1-70b-instruct-v1.0"),
    description="You write movie scripts.",
    output_schema=MovieScript,
)

# Get the response in a variable
# json_mode_response: RunOutput = json_mode_agent.run("New York")
# pprint(json_mode_response.content)
# structured_output_response: RunOutput = structured_output_agent.run("New York")
# pprint(structured_output_response.content)

json_mode_agent.print_response("New York")
structured_output_agent.print_response("New York")

Usage

Set up your virtual environment

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

Export environment variables

export LANGDB_API_KEY="your_langdb_api_key"
export LANGDB_PROJECT_ID="your_langdb_project_id"
export LANGDB_API_BASE_URL="https://api.langdb.ai"

Install dependencies

uv pip install -U openai agno

Run Agent

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

python structured_output.py