Agent with Structured Outputs

Constrain a local LM Studio agent to return a MovieScript Pydantic object instead of free-form text.

Code

from typing import List

from agno.agent import Agent
from agno.models.lmstudio import LMStudio
from agno.run.agent import RunOutput
from pydantic import BaseModel, Field
from rich.pretty import pprint

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 that returns a structured output
structured_output_agent = Agent(
    model=LMStudio(id="qwen2.5-7b-instruct-1m"),
    description="You write movie scripts.",
    output_schema=MovieScript,
)

# Run the agent synchronously
structured_output_response: RunOutput = structured_output_agent.run("New York")
pprint(structured_output_response.content)

Use a model suitable for JSON schema output in LM Studio. Agno sends MovieScript as a JSON schema and parses the response into that Pydantic model.

Usage

Set up your virtual environment

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

Start the LM Studio API server

Install LM Studio, download and load a model, then open Developer and start the API server on port 1234. Keep the server running while you run Python in a terminal.

Check the model list:

curl http://127.0.0.1:1234/v1/models

Set LMStudio(id=...) in the example to the exact model id returned by your server. If you change the server port, set the matching base_url on LMStudio.

Install dependencies

uv pip install -U openai agno

Run Agent

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

python structured_output.py