# Custom action
<a name="journey-flow-block-custom-action"></a>

## Description
<a name="journey-flow-block-custom-action-description"></a>

Use this block to call Lambda functions that fetch, validate, or transform data for use in the journey.

## How to configure this block
<a name="journey-flow-block-custom-action-configure"></a>

You can configure the **Custom action** block in the admin website or using the InvokeLambda action.

### Common properties
<a name="journey-flow-block-custom-action-common-properties"></a>


| Property | Description | 
| --- | --- | 
| Action | Select Invoke Lambda action | 
| Function ARN | Select a registered Lambda function. | 

**Example**

Invoke a Lambda to check offer eligibility, store the result in eligibilityStatus, and branch accordingly.

## Configuration
<a name="journey-flow-block-custom-action-configuration"></a>

Before you can invoke a Lambda using this block, you need to set up your Lambda functions at your Amazon Connect instance at AWS admin console. For similar information, see [Grant Connect Customer access to your AWS Lambda functions](connect-lambda-functions.md).

When you do this for a journey flow block, you use the **Outbound campaigns** under the **Channels and communications** section, and to choose your Lambda function, you use the **Set up custom actions** section and then the **Lambda Functions** drop down.