> **Experimental**
>
> `@aws-cdk/integ-tests-alpha` is an [**experimental**](/stability) (alpha) package: its API may change in any release, without a major version bump.
# InvocationType

The type of invocation.

Default is REQUEST_RESPONSE

- Stability: [Experimental](/cdk/api/stability.html)
- Source: [`lib/assertions/sdk.ts`](https://github.com/aws/aws-cdk/blob/v2.275.0-alpha.0/packages/@aws-cdk/integ-tests-alpha/lib/assertions/sdk.ts#L179)

## Example

```ts
declare const app: App;
declare const stack: Stack;
declare const queue: sqs.Queue;
declare const fn: lambda.IFunction;

const integ = new IntegTest(app, 'Integ', {
  testCases: [stack],
});

integ.assertions.invokeFunction({
  functionName: fn.functionName,
  invocationType: InvocationType.EVENT,
  payload: JSON.stringify({ status: 'OK' }),
});

const message = integ.assertions.awsApiCall('SQS', 'receiveMessage', {
  QueueUrl: queue.queueUrl,
  WaitTimeSeconds: 20,
});

message.assertAtPath('Messages.0.Body', ExpectedResult.objectLike({
  requestContext: {
    condition: 'Success',
  },
  requestPayload: {
    status: 'OK',
  },
  responseContext: {
    statusCode: 200,
  },
  responsePayload: 'success',
}));
```

## Members

| Member | Description |
| --- | --- |
| `EVENT` | Invoke the function asynchronously. |
| `REQUEST_RESPONSE` | Invoke the function synchronously. |
| `DRY_RUN` | Validate parameter values and verify that the user or role has permission to invoke the function. |

## Referenced by

- [`LambdaInvokeFunctionProps`](/v2/docs/@aws-cdk_integ-tests-alpha.LambdaInvokeFunctionProps).invocationType