> ## Documentation Index
> Fetch the complete documentation index at: https://docs.definable.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Model as String

> Use string shorthand instead of importing model classes.

Instead of importing model classes, pass a string to `Agent(model=...)`:

```python theme={null}
from definable.agent import Agent

# Full format: "provider/model-id"
agent = Agent(model="openai/gpt-4o")
agent = Agent(model="anthropic/claude-sonnet-4-20250514")
agent = Agent(model="google/gemini-2.0-flash-001")
agent = Agent(model="deepseek/deepseek-chat")

# Bare model name defaults to OpenAI
agent = Agent(model="gpt-4o")
agent = Agent(model="gpt-4o-mini")
```

## Supported Providers

| Provider      | Format                | Example                              |
| ------------- | --------------------- | ------------------------------------ |
| OpenAI        | `openai/model-id`     | `openai/gpt-4o`                      |
| Anthropic     | `anthropic/model-id`  | `anthropic/claude-sonnet-4-20250514` |
| Google Gemini | `google/model-id`     | `google/gemini-2.0-flash-001`        |
| DeepSeek      | `deepseek/model-id`   | `deepseek/deepseek-chat`             |
| Mistral       | `mistral/model-id`    | `mistral/mistral-large-latest`       |
| Moonshot      | `moonshot/model-id`   | `moonshot/moonshot-v1-8k`            |
| xAI           | `xai/model-id`        | `xai/grok-3`                         |
| Perplexity    | `perplexity/model-id` | `perplexity/sonar-pro`               |
| Ollama        | `ollama/model-id`     | `ollama/llama3`                      |
| OpenRouter    | `openrouter/model-id` | `openrouter/meta-llama/llama-3-70b`  |

## When to Use Class Imports

Use the class-based approach when you need to configure model-specific options:

```python theme={null}
from definable.model.openai import OpenAIChat

model = OpenAIChat(
    id="gpt-4o",
    api_key="sk-...",          # Custom API key
    strict_output=False,       # Disable strict JSON mode
    base_url="https://...",    # Custom endpoint
)
```

String shorthand uses default configuration for each provider.