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You will often want to run code before your AgentOS app starts or before it shuts down. This can be done by providing a custom lifespan function via the lifespan parameter. This is how a lifespan function looks like: 
@asynccontextmanager
async def lifespan(app):
    # This will run before your app starts
    log_info("Starting My FastAPI App")

    yield

    # This will run before your app shuts down
    log_info("Stopping My FastAPI App")

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FastAPI Lifespan

The custom lifespan function you provide will be used as the lifespan context manager for the FastAPI app used by your AgentOS. Remember to decorate it with @asynccontextmanager as shown in the examples.
See the FastAPI documentation for more information about the lifespan context manager.
If you are using a custom FastAPI app, you don’t need to worry about overwriting its lifespan. The lifespan you provide will wrap the existing lifespan of the app, letting you combine all.

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Common Use Cases

Lifespan control is useful to handle typical startup and shutdown tasks, such as:
  • Resource Initialization: databases, third party services, caches… or anything else needed by your app.
  • Cleanup: Close connections, store data or release resources before shut down.
  • Health Checks: Verify dependencies are available before serving requests
  • Background Tasks: Start/stop background processes

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Example

1

Code

custom_lifespan.py
from contextlib import asynccontextmanager

from agno.agent import Agent
from agno.db.postgres import PostgresDb
from agno.models.anthropic import Claude
from agno.os import AgentOS
from agno.utils.log import log_info

# Setup the database
db = PostgresDb(db_url="postgresql+psycopg://ai:ai@localhost:5532/ai")

# Setup basic agents, teams and workflows
agno_support_agent = Agent(
    id="example-agent",
    name="Example Agent",
    model=Claude(id="claude-sonnet-4-0"),
    db=db,
    markdown=True,
)


@asynccontextmanager
async def lifespan(app):
    log_info("Starting My FastAPI App")
    yield
    log_info("Stopping My FastAPI App")


agent_os = AgentOS(
    description="Example app with custom lifespan",
    agents=[agno_support_agent],
    lifespan=lifespan,
)


app = agent_os.get_app()

if __name__ == "__main__":
    """Run your AgentOS.

    You can see test your AgentOS at:
    http://localhost:7777/docs

    """
    agent_os.serve(app="custom_lifespan:app")
2

Create a virtual environment

Open the Terminal and create a python virtual environment.
python3 -m venv .venv
source .venv/bin/activate
3

Set Environment Variables

export ANTHROPIC_API_KEY=your_anthropic_api_key
4

Install libraries

pip install -U agno anthropic "fastapi[standard]" uvicorn sqlalchemy
5

Setup PostgreSQL Database

# Using Docker
docker run -d \
  --name agno-postgres \
  -e POSTGRES_DB=ai \
  -e POSTGRES_USER=ai \
  -e POSTGRES_PASSWORD=ai \
  -p 5532:5432 \
  pgvector/pgvector:pg17
6

Run Example with Python

fastapi run custom_lifespan.py