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

# start • AI Agent SDK

> start: Start the heartbeat loop.

# start

<div className="flex items-center gap-2">
  <Badge color="purple">Method</Badge>
</div>

> This is a method of the [**Heartbeat**](../classes/Heartbeat) class in the [**heartbeat**](../modules/heartbeat) module.

Start the heartbeat loop.

## Signature

```python theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
def start(blocking: bool) -> None
```

## Parameters

<ParamField query="blocking" type="bool" required={false} default="True">
  If True, blocks the calling thread. If False, runs in a background daemon thread.
</ParamField>

## Uses

* `threading.Thread`
* `start`

## Used By

* [`Heartbeat.start`](../functions/Heartbeat-start)
* [`AgentTeam.start`](../functions/AgentTeam-start)
* [`AgentTeam.run`](../functions/AgentTeam-run)
* [`AgentTeam.start_for_each`](../functions/AgentTeam-start_for_each)
* [`AgentTeam.spawn_sub_agent`](../functions/AgentTeam-spawn_sub_agent)

## Source

<Card title="View on GitHub" icon="github" href="https://github.com/MervinPraison/PraisonAI/blob/main/src/praisonai-agents/praisonaiagents/agent/heartbeat.py#L81">
  `praisonaiagents/agent/heartbeat.py` at line 81
</Card>