# Flow Fail

Documentation owner: module `pipes`; documentation version: `2026.117`.
Source: `content/modules/pipes/2026.117/valves/flow/flow-fail.mdx` at commit `eaf7a020437971baeee95e87eaf963636040ac71`.

## Introduction

Valve to explicitly fail a Flow. Use with `"exec_if_expr"` for conditional fail.

## Configuration

:::note
**Valve name:** `FlowFail`
:::

### Properties

| Name | Description | Default value | Mandatory | Expanded |
| --- | --- | --- | --- | --- |
| `message` | Reason message returned to caller. | `"Failed by FlowFail valve"` | No | Yes |

### Example

```json
{
  "name" : "FlowFail",
  "exec_if_expr": "request.user != null",
  "config" : {
    "message" : "Missing input param 'user'"
  }
}
```