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

# Router with CEL expression: ternary operator on input content

> Uses a CEL ternary to pick between two steps based on whether the input mentions "video" or not.

```python cel_ternary.py theme={null}
"""Router with CEL expression: ternary operator on input content.
==============================================================

Uses a CEL ternary to pick between two steps based on whether
the input mentions "video" or not.

Requirements:
    pip install cel-python
"""

from agno.agent import Agent
from agno.models.openai import OpenAIChat
from agno.workflow import CEL_AVAILABLE, Step, Workflow
from agno.workflow.router import Router

# ---------------------------------------------------------------------------
# Setup
# ---------------------------------------------------------------------------
if not CEL_AVAILABLE:
    print("CEL is not available. Install with: pip install cel-python")
    exit(1)

# ---------------------------------------------------------------------------
# Create Agents
# ---------------------------------------------------------------------------
video_agent = Agent(
    name="Video Specialist",
    model=OpenAIChat(id="gpt-4o-mini"),
    instructions="You specialize in video content creation and editing advice.",
    markdown=True,
)

image_agent = Agent(
    name="Image Specialist",
    model=OpenAIChat(id="gpt-4o-mini"),
    instructions="You specialize in image design, photography, and visual content.",
    markdown=True,
)

# ---------------------------------------------------------------------------
# Create Workflow
# ---------------------------------------------------------------------------
workflow = Workflow(
    name="CEL Ternary Router",
    steps=[
        Router(
            name="Media Router",
            selector='input.contains("video") ? "Video Handler" : "Image Handler"',
            choices=[
                Step(name="Video Handler", agent=video_agent),
                Step(name="Image Handler", agent=image_agent),
            ],
        ),
    ],
)

# ---------------------------------------------------------------------------
# Run Workflow
# ---------------------------------------------------------------------------
if __name__ == "__main__":
    print("--- Video request ---")
    workflow.print_response(input="How do I edit a video for YouTube?")
    print()

    print("--- Image request ---")
    workflow.print_response(input="Help me design a logo for my startup.")
```

## Run the Example

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

  <Step title="Install dependencies">
    ```bash theme={null}
    uv pip install -U agno cel-python fastapi openai
    ```
  </Step>

  <Step title="Export your OpenAI API key">
    <CodeGroup>
      ```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"
      ```
    </CodeGroup>
  </Step>

  <Step title="Run the example">
    Save the code above as `cel_ternary.py`, then run:

    ```bash theme={null}
    python cel_ternary.py
    ```
  </Step>
</Steps>

Full source: [cookbook/04\_workflows/07\_cel\_expressions/router/cel\_ternary.py](https://github.com/agno-agi/agno/blob/main/cookbook/04_workflows/07_cel_expressions/router/cel_ternary.py)