result = {'success': False, 'message': 'Invalid callback'}

try:
    # DingTalk callback data comes via params_kw (POST body auto-parsed)
    callback_data = {}

    # params_kw contains the parsed POST body fields
    process_instance_id = params_kw.get('processInstanceId', '')
    callback_type = params_kw.get('type', '')
    callback_result = params_kw.get('result', '')
    staff_id = params_kw.get('staffId', '')
    process_code = params_kw.get('processCode', '')
    remark = params_kw.get('remark', '')

    # Also handle nested JSON body case where entire body is under a key
    if not process_instance_id:
        body = params_kw.get('body', None)
        if isinstance(body, dict):
            process_instance_id = body.get('processInstanceId', '')
            callback_type = body.get('type', '')
            callback_result = body.get('result', '')
            staff_id = body.get('staffId', '')
            process_code = body.get('processCode', '')
            remark = body.get('remark', '')

    callback_data = {
        'processInstanceId': process_instance_id,
        'type': callback_type,
        'result': callback_result,
        'staffId': staff_id,
        'processCode': process_code,
        'remark': remark,
    }

    if not process_instance_id:
        result = {'success': False, 'message': 'Missing processInstanceId'}
    else:
        # Call the handle_dingtalk_callback function registered via load_dingdingflow()
        callback_result_data = await handle_dingtalk_callback(callback_data)
        result = callback_result_data

except Exception as e:
    result = {'success': False, 'message': f'Callback processing error: {str(e)}'}

return result