> ## Documentation Index
> Fetch the complete documentation index at: https://phidatainc-agui.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# What are Models?

> Language Models are machine-learning programs that are trained to understand natural language and code.

When we discuss Models, we are normally referring to Large Language Models (LLMs).

These models act as the **brain** of your Agents - enabling them to reason, act, and respond to the user. The better the model, the smarter the Agent.

```python theme={null}
from agno.agent import Agent
from agno.models.openai import OpenAIResponses

agent = Agent(
    model=OpenAIResponses(id="gpt-5.2"),
    description="Share 15 minute healthy recipes.",
    markdown=True,
)
agent.print_response("Share a breakfast recipe.", stream=True)
```

<Tip>
  Use [model strings](/models/model-as-string) (`"provider:model_id"`) for simpler configuration. For advanced use cases requiring custom parameters like `temperature` or `max_tokens`, use the full model class syntax.
</Tip>

## Error handling

You can configure your Model to retry requests if they fail. This is useful to handle temporary failures or rate limiting errors from the model provider.

```python theme={null}
model = OpenAIResponses(
  id="gpt-5.2",
  retries=2, # Number of retries to attempt before raising a ModelProviderError
  retry_delay=1, # Delay between retries, in seconds
  exponential_backoff=True, # If True, the delay between retries is doubled each time
)
```

<Note>
  You can also configure `retries`, `delay_between_retries`, and `exponential_backoff` directly on your Agent or Team, to retry the full runs instead of just the Model requests.
</Note>

## Learn more

<CardGroup cols={2}>
  <Card title="Supported Model Providers" icon="layer-group" href="/models/providers/model-index">
    See the full list of supported model providers.
  </Card>

  <Card title="Model-as-string" icon="code" href="/models/model-as-string">
    Use the convenient provider:model\_id string format to specify models without importing model classes.
  </Card>

  <Card title="Compatibility" icon="code-compare" href="/models/compatibility">
    See what features are supported by each model provider.
  </Card>

  <Card title="Cache Response" icon="database" href="/models/cache-response">
    Cache the response from the model provider to avoid duplicate API calls.
  </Card>

  <Card title="Fallback Models" icon="rotate" href="/models/fallback-models">
    Switch to backup models automatically on rate limits, outages, or context window errors.
  </Card>
</CardGroup>