> ## Documentation Index
> Fetch the complete documentation index at: https://agno-v2.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Chat Agent Flex Tier

> Run o4-mini on the flex service tier by setting service_tier on OpenAIChat.

```python agent_flex_tier.py theme={null}
"""
Openai Agent Flex Tier
======================

Cookbook example for `openai/chat/agent_flex_tier.py`.
"""

from agno.agent import Agent
from agno.models.openai import OpenAIChat

# ---------------------------------------------------------------------------
# Create Agent
# ---------------------------------------------------------------------------

agent = Agent(
    model=OpenAIChat(id="o4-mini", service_tier="flex"),
    markdown=True,
)

agent.print_response("Share a 2 sentence horror story")

# ---------------------------------------------------------------------------
# Run Agent
# ---------------------------------------------------------------------------

if __name__ == "__main__":
    pass
```

## Run the Example

<Snippet file="create-venv-step.mdx" />

**1. Install dependencies**

```bash theme={null}
uv pip install -U agno openai
```

**2. Export your OpenAI API key**

```bash Mac/Linux theme={null}
export OPENAI_API_KEY="your_openai_api_key_here"
```

```bash Windows theme={null}
$Env:OPENAI_API_KEY="your_openai_api_key_here"
```

**3. Run the example**

Save the code above as `agent_flex_tier.py`, then run:

```bash theme={null}
python agent_flex_tier.py
```

Full source: [cookbook/90\_models/openai/chat/agent\_flex\_tier.py](https://github.com/agno-agi/agno/blob/v3.0.4/cookbook/90_models/openai/chat/agent_flex_tier.py)


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