> ## 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 Session • Rust AI Agent SDK

> start_session: Start a new thinking session. # Arguments * `budget_tokens` - Token budget for this session * `budget_time` - Optional time budget * `complexity` -...

# start\_session

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  <Badge color="purple">Method</Badge>
</div>

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

Start a new thinking session. # Arguments \* `budget_tokens` - Token budget for this session \* `budget_time` - Optional time budget \* `complexity` - Task complexity (0.0 to 1.0) # Returns Index of the new session

## Signature

```python theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
def start_session(
        &mut self,
        budget_tokens: usize,
        budget_time: Option<f64>,
        complexity: f64,
    ) -> usize
```

## Parameters

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

<ParamField query="budget_time" type="Option<f64>" required={true}>
  No description available.
</ParamField>

<ParamField query="complexity" type="f64" required={true}>
  No description available.
</ParamField>

### Returns

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

***

## Related Documentation

<CardGroup cols={2}>
  <Card title="Rust Sessions" icon="clock" href="/docs/rust/sessions" />

  <Card title="Rust Memory" icon="database" href="/docs/rust/memory" />
</CardGroup>