# Structured outputs (/faq/structured-outputs)



Agno agents support two methods for schema-compliant responses: **Structured Outputs** and **JSON mode**. Both use the agent's `output_schema` parameter.

## Structured Outputs (Default if supported) [#structured-outputs-default-if-supported]

If the model class supports it, Agno agents use Structured Outputs by default. The schema (Pydantic or JSON Schema) is passed to the model provider's API. For successfully completed, non-refusal responses, providers that support strict Structured Outputs validate the response against that schema. Handle refusals, incomplete generations, and provider errors separately.

```python
from pydantic import BaseModel
from agno.agent import Agent
from agno.models.openai import OpenAIChat

class User(BaseModel):
    name: str
    age: int
    email: str

agent = Agent(
    model=OpenAIChat(id="gpt-5.4-mini"),
    description="You are a helpful assistant that can extract information from a user's profile.",
    output_schema=User,
)
```

`Agent.run()` returns a `RunOutput`; for a successfully parsed response, its `.content` contains the `User` object instead of free-form text. Structured Outputs are a good fit for tasks where the output shape has to be right, like entity extraction or generating content for UI rendering.

## JSON Mode [#json-mode]

Some model classes do not support Structured Outputs, and sometimes you want to bypass it even when they do. Set `use_json_mode=True` to enable JSON mode.

```python
from pydantic import BaseModel
from agno.agent import Agent
from agno.models.openai import OpenAIChat

class User(BaseModel):
    name: str
    age: int
    email: str

agent = Agent(
    model=OpenAIChat(id="gpt-5.4-mini"),
    description="You are a helpful assistant that can extract information from a user's profile.",
    output_schema=User,
    use_json_mode=True,
)
```

JSON mode injects a description of the expected JSON structure into the system prompt and instructs the model to return valid JSON. The response is not validated against the schema at the API level.

## When to Use Which [#when-to-use-which]

| Situation                                             | Mode                                      |
| ----------------------------------------------------- | ----------------------------------------- |
| Model supports Structured Outputs                     | Structured Outputs (default)              |
| Model lacks Structured Outputs support                | JSON mode (Agno falls back automatically) |
| Model can't combine tools with Structured Outputs     | JSON mode                                 |
| Broad compatibility matters and you validate manually | JSON mode                                 |

## Next Steps [#next-steps]

* [Structured output for agents](/input-output/structured-output/agent)
* [Model compatibility](/models/compatibility)