Creating a Subscription

Function

This API is used to create device operations under an application in a specified instance and subscribe to the specified topic.

URI

POST /v2/{project_id}/link/instances/{instance_id}/notifications

**Table 1** Path Parameters
Parameter	Mandatory	Type	Description
project_id	Yes	String	Project ID. For details about how to obtain the project ID, see Appendix > Obtaining a Project ID in the ROMA Connect API Reference.
instance_id	Yes	String	Instance ID.

Request Parameters

**Table 2** Request header parameters
Parameter	Mandatory	Type	Description
X-Auth-Token	Yes	String	User token, which can be obtained by calling the IAM API (value of X-Subject-Token in the response header).

**Table 3** Request body parameters
Parameter	Mandatory	Type	Description
app_id	Yes	String	ID of the application to which a notification belongs. This parameter is transferred only when an application-level subscription is created. If neither app_id nor product_serial is specified, an instance-level subscription is created.
type	Yes	Integer	Notification type. The options include 0 (device online), 1 (device offline), 2 (device addition), 3 (device deletion), and 4 (device change).
topic	Yes	String	Name of the topic to which a notification is sent. The topic must exist in MQS.
status	Yes	Integer	Start/Stop status. The options include 0 (enabled) and 1 (disabled).

Response Parameters

Status code: 200

**Table 4** Response body parameters
Parameter	Type	Description
notification_id	Integer	Subscription ID.
type	Integer	Subscription type. The options include 0 (device online), 1 (device offline), 2 (device addition), 3 (device deletion), and 4 (device change).
status	Integer	Subscription management status. The options include 0 (enabled) and 1 (disabled).
topic	String	Name of the subscribed topic.
instance_id	String	Instance ID.
app_id	String	Application ID.

Status code: 400

**Table 5** Response body parameters
Parameter	Type	Description
error_code	String	System error code, which is the detailed error code of HTTP error codes 4xx and 5xx.
error_msg	String	Error description.
request_id	String	Message ID.

Status code: 404

**Table 6** Response body parameters
Parameter	Type	Description
error_code	String	System error code, which is the detailed error code of HTTP error codes 4xx and 5xx.
error_msg	String	Error description.
request_id	String	Message ID.

Status code: 500

**Table 7** Response body parameters
Parameter	Type	Description
error_code	String	System error code, which is the detailed error code of HTTP error codes 4xx and 5xx.
error_msg	String	Error description.
request_id	String	Message ID.

Example Requests

Subscribe to notifications when devices of a specified integration application are online and send messages to a specified MQS topic.

{
  "app_id" : "ef3845be-091a-4ab5-869a-9de0025e2165",
  "type" : 0,
  "topic" : "online",
  "status" : 0
}

Example Responses

Status code: 200

Created

{
  "notification_id" : 100,
  "type" : 0,
  "status" : 0,
  "topic" : "string",
  "instance_id" : "string",
  "app_id" : "string"
}

Status code: 404

Not Found

{
  "error_code" : "ROMA.00110006",
  "error_msg" : "The resource does not exist. Check whether the resource ID 1 is correct.",
  "request_id" : "624c8be1-39b6-47b7-941d-c159aced368a-1619602544650-cnnorth7a-P-romalink-service01"
}