> ## 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.

# Window Start • AI Agent SDK

> window_start: Start timestamp of the current window for a ``now`` timestamp.

# window\_start

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

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

Start timestamp of the current window for a `now` timestamp.

Helper for the wrapper so it can query the durable sink for
`spent_usd` over the same window the policy enforces.

## Signature

```python theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
def window_start(now: float) -> float
```

## Parameters

<ParamField query="now" type="float" required={true}>
  No description available.
</ParamField>

### Returns

<ResponseField name="Returns" type="float">
  The result of the operation.
</ResponseField>

## Source

<Card title="View on GitHub" icon="github" href="https://github.com/MervinPraison/PraisonAI/blob/main/src/praisonai-agents/praisonaiagents/gateway/protocols.py#L4439">
  `praisonaiagents/gateway/protocols.py` at line 4439
</Card>