Serverless Workflow API operations use the RPC protocol. You can call Serverless Workflow API operations by sending HTTP GET or HTTP POST requests. This topic describes how to call Serverless Workflow API operations. Each API request must contain parameters and be signed and authenticated.

Request syntax

This section describes the syntax of an API request sent over HTTP or HTTPS.

Use the following URL format for a GET request. The URL must be encoded in UTF-8.

http(s)://Endpoint/? Action=xx&Parameters
  • Endpoint: the endpoint of the Serverless Workflow API.
  • Action: the name of the operation being performed. For example, to execute a flow, you must set the Action parameter to StartExecution.
  • Parameters: the request parameters for the operation. Separate multiple parameters with ampersands (&). Request parameters include both common parameters and operation-specific parameters.

The following example demonstrates how to call the StartExecution operation in Serverless Workflow:

&Common request parameters
Note We recommend that you send API requests over HTTPS to enhance security.


The endpoint of Serverless Workflow API is

Network type Region Endpoint
Internet service China (Hangzhou) {account-id}
China (Shanghai) {account-id}
China (Beijing) {account-id}
China (Shenzhen) {account-id}
US (Silicon Valley) {account-id}
Singapore {account-id}
Internal network service China (Hangzhou) {account-id}
China (Shanghai) {account-id}
China (Beijing) {account-id}
China (Shenzhen) {account-id}
US (Silicon Valley) {account-id}
Singapore {account-id}
Note The {account-id} in the preceding table must be changed to your account ID. You can click the profile picture in the upper-right corner of the Serverless Workflow console to view the enterprise alias, which is your account ID.

Common parameters

The following table describes common request parameters that can be used when you call Serverless Workflow API operations by sending GET requests over URLs.

Parameter Type Required Example Description
Action String Yes StartExecution The operation that you want to perform.
AccessKeyId String Yes LTAIp4********fjx The AccessKey ID provided to you by Alibaba Cloud. For more information, see Create an AccessKey pair.
Signature String Yes OLeaidS1JvxuMvnyHOwuJ%2BuX5qY%3D The signature string of the current request.
SignatureMethod String Yes HMAC-SHA1 The encryption method of the signature string. Default value: HMAC-SHA1.
SignatureVersion String Yes 1.0 The version of the signature encryption algorithm. Default value: 1.0.
SignatureNonce String Yes 3ee8c1b8-****-44af-****-4e0ad82fd6cf A unique, random number used to prevent replay attacks. You must use different numbers for different requests.
Timestamp String Yes 2018-01-01T12:00:00Z The timestamp of the request. Specify the time in the ISO 8601 standard in the yyyy-MM-ddTHH:mm:ssZ format. The time must be in UTC+0.
Version String Yes 2019-03-15 The version number of the API. The value must be in the YYYY-MM-DD format. Default value: 2019-03-15.
Format String No json The format in which to return the response. Valid values: JSON and XML. Default value: JSON.