Make API requests - - Alibaba Cloud Documentation Center

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:

https://[Endpoint]/?Action=StartExecution
&FlowName=Flow
&Common request parameters

Note We recommend that you send API requests over HTTPS to enhance security.

Endpoint

The endpoint of Serverless Workflow API is XXX.aliyuncs.com.

Network type	Region	Endpoint
Internet service	China (Hangzhou)	{account-id}.cn-hangzhou.fnf.aliyuncs.com
	China (Shanghai)	{account-id}.cn-shanghai.fnf.aliyuncs.com
	China (Beijing)	{account-id}.cn-beijing.fnf.aliyuncs.com
	China (Shenzhen)	{account-id}.cn-shenzhen.fnf.aliyuncs.com
	US (Silicon Valley)	{account-id}.us-west-1.fnf.aliyuncs.com
	Singapore	{account-id}.ap-southeast-1.fnf.aliyuncs.com
Internal network service	China (Hangzhou)	{account-id}.cn-hangzhou-internal.fnf.aliyuncs.com
	China (Shanghai)	{account-id}.cn-shanghai-internal.fnf.aliyuncs.com
	China (Beijing)	{account-id}.cn-beijing-internal.fnf.aliyuncs.com
	China (Shenzhen)	{account-id}.cn-shenzhen-internal.fnf.aliyuncs.com
	US (Silicon Valley)	{account-id}.us-west-1-internal.fnf.aliyuncs.com
	Singapore	{account-id}.ap-southeast-1-internal.fnf.aliyuncs.com

Note The {account-id} in the preceding table must be changed to your Alibaba Cloud 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 Obtain an AccessKey pair.
Signature	String	Yes	OLeaidS1JvxuMvnyHOwuJ%2BuX5qY%3D	The signature string of the current request. For more information, see RPC invocation method.
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.