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

# Choose which application owns conflicting routes

> An existing FastAPI app defines ``/`` and ``/health``, which AgentOS also provides.

An existing FastAPI app defines `/` and `/health`, which AgentOS also provides. `on_route_conflict="preserve_base_app"` keeps those custom handlers while AgentOS still registers non-conflicting routes such as `/config` and the agent run surface.

```python route_conflicts.py theme={null}
"""
Choose which application owns conflicting routes
================================================

An existing FastAPI app defines ``/`` and ``/health``, which AgentOS also
provides. ``on_route_conflict="preserve_base_app"`` keeps those custom
handlers while AgentOS still registers non-conflicting routes such as
``/config`` and the agent run surface.

Prerequisites: none for the serve-and-curl flow below (OPENAI_API_KEY only
if you send the agent a run)
Run: .venvs/demo/bin/python cookbook/05_agent_os/06_customize/route_conflicts.py
Try: curl http://localhost:7777/health
"""

from agno.agent import Agent
from agno.db.sqlite import SqliteDb
from agno.models.openai import OpenAIResponses
from agno.os import AgentOS
from fastapi import FastAPI

# ---------------------------------------------------------------------------
# Create Conflicting Base Application and AgentOS
# ---------------------------------------------------------------------------

db = SqliteDb(
    id="route-conflict-db",
    db_file="tmp/agent_os_route_conflicts.db",
)

route_agent = Agent(
    id="route-conflict-agent",
    name="Route Conflict Agent",
    model=OpenAIResponses(id="gpt-5.5"),
    db=db,
)

base_app = FastAPI(title="Custom Route Owner")


@base_app.get("/")
async def custom_home() -> dict[str, str]:
    """Return the base application's custom landing page."""
    return {"owner": "base_app", "route": "/"}


@base_app.get("/health")
async def custom_health() -> dict[str, str]:
    """Return the base application's custom health contract."""
    return {"status": "custom_ok", "owner": "base_app"}


agent_os = AgentOS(
    id="route-conflict-os",
    db=db,
    agents=[route_agent],
    base_app=base_app,
    on_route_conflict="preserve_base_app",
)
app = agent_os.get_app()

# ---------------------------------------------------------------------------
# Run Conflict Policy Example
# ---------------------------------------------------------------------------

if __name__ == "__main__":
    agent_os.serve(app=app, port=7777)
```

## Run the Example

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

  <Step title="Install dependencies">
    ```bash theme={null}
    uv pip install -U "agno[os]" 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 `route_conflicts.py`, then run:

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

Full source: [cookbook/05\_agent\_os/06\_customize/route\_conflicts.py](https://github.com/agno-agi/agno/blob/v3.0.4/cookbook/05_agent_os/06_customize/route_conflicts.py)