API Invocation

Invoke HTTP RESTful API via MQTT:

• Request messages are described using method, url, and body fields for the HTTP RESTful API request.
• Response messages are described using code and body fields for the HTTP RESTful API response.
• Both request and response messages use the id field for correlation.

Interaction Flow

sequenceDiagram

participant Server as User Application Service
participant MQTT as User MQTT Server
participant Gateway as Cassia Bluetooth Gateway
participant Device as User BLE Device

rect rgba(136, 177, 234,0.4)
    Server --) Gateway: API Request
    Gateway --) Gateway: Request Processing
    opt
      rect rgba(136, 177, 234,0.4)
      note over Gateway,Device: BLE Interaction
      Gateway --) Device: BLE Request
      Device -) Device: BLE Request Processing
      Device --) Gateway: BLE Response
      Gateway --) Gateway: Response Processing
      end
    end
    Gateway --) Server: API Response
end

API Request

Topic	Action	Data.url Field	Further Reference
down/{gateway}/api	api	BLE API	Cassia RESTful API

Request Message

{
  "id": "35656",
  "action": "api",
  "timestamp": 1678698297028,
  "gateway": "CC:1B:E0:E2:8F:2C",
  "data": {
    "url": "/gap/nodes/D8:0B:CB:62:5C:2B/connection?",
    "method": "POST",
    "body": {}
  }
}

Field Descriptions

Field	Field	Type	Required	Default	Description
id		string	Yes	-	Message ID, unique identifier, response message ID consistent with request
action		string	Yes	-	Message type distinction
timestamp		uint32	Yes	-	Timestamp in milliseconds
gateway		string	Yes	-	Gateway MAC address
data		object	Yes	-	Message payload
	url	string	Yes	-	HTTP API URL, including options and query parameters
	method	string	Yes	-	HTTP API method
	body	object/array	Yes	-	HTTP API body

API Response

Topic	Action
up/{gateway}/api_reply	api_reply

Response Message

{
  "id": "35656",
  "action": "api_reply",
  "timestamp": 1678698297028,
  "gateway": "CC:1B:E0:E2:8F:2C",
  "data": {
    "code": 200,
    "body": {}
  }
}

Field Descriptions

Field	Field	Type	Required	Default	Description
id		string	Yes	-	Message ID, unique identifier, response message ID consistent with request
action		string	Yes	-	Message type
timestamp		uint32	Yes	-	Timestamp in milliseconds
gateway		string	Yes	-	Gateway MAC address
data		object	Yes	-	Message payload
	code	uint32	Yes	-	HTTP status code
	body	object/array	Yes	-	HTTP API response body