> ## 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.

# If • Rust AI Agent SDK

> If: Builder for creating conditions.

# If

> Defined in the [**conditions**](../modules/conditions) module.

<Badge color="orange">Rust AI Agent SDK</Badge>

Builder for creating conditions.

## Methods

### `expr`

```rust theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
fn expr(expression: impl Into<String>) -> ExpressionCondition
```

Create an expression condition.

**Parameters:**

| Name         | Type                      |
| ------------ | ------------------------- |
| `expression` | `impl Into&lt;String&gt;` |

## Source

<Card title="View on GitHub" icon="github" href="https://github.com/MervinPraison/PraisonAI/blob/main/src/praisonai-rust/praisonai/src/conditions/mod.rs#L295">
  `praisonai/src/conditions/mod.rs` at line 295
</Card>