receiver3.py

def lambda_handler(event, context):
    # ....
    # Get the event type
    event_type = body.get('type', '')

    # Check for edited messages
    if (
        event_type == 'event_callback' and 
        'edited' in body.get('event', {})
    ):
        print('Detected edited message, discarding')
        return {
            'statusCode': 200,
            'body': json.dumps({'message': 'Edited message discarded'})
        }

    # Only process events we care about
    if event_type == 'event_callback':
        # Asynchronously invoke the processor Lambda
        lambda_client.invoke(
            FunctionName=os.environ['PROCESSOR_FUNCTION_NAME'],
            InvocationType='Event',  # Async invocation
            Payload=json.dumps(event)
        )

    # Always return 200 OK to Slack quickly
    return {
        'statusCode': 200,
        'body': json.dumps({'message': 'Event received'})
    }