# REST API

EMQ X Cloud API follows the REST architecture, and you can access the functions of EMQ X programmatically.

# API Overview

APIDescription
Authentication managementManage the creation, deletion and update of authentication information
ACL managementManage the creation, deletion and update of ACL information
Client managementView the online client information and kick off the client
Message SubscriptionCheck subscribed message
Topic SubscriptionSubscribe, unsubscribe, batch subscribe, batch unsubscribe
Message PublishPublish, batch publish
MetricsCheck metrics

# How to Use API

# Construct Request

The request address consists of the following parts:

{API}/{resource-path}?{query-string}

You can get the API access address in the API access section under the deployment details page

api

# Authentication

HTTP API uses Basic authentication (opens new window) method, ID and password must be filled in AppID and AppSecret respectively. You can add and remove AppID/AppSecret by creating new application in the API access under the deployment details page.

# Response code

# HTTP status codes

The EMQ X Broker interface always returns 200 OK when the call is successful, and the response content is returned in JSON format.

The possible status codes are as follows:

Status CodeDescription
200Succeed, and the returned JSON data will provide more information
400Invalid client request, such as wrong request body or parameters
401Client authentication failed , maybe because of invalid authentication credentials
404The requested path cannot be found or the requested object does not exist
500An internal error occurred while the server was processing the request

# Result codes

The response message body of the EMQ X Broker interface is in JSON format, which always contains the returned code.

The possible result codes are as follows:

Return CodeDescription
0Succeed
101RPC error
102unknown mistake
103wrong user name or password
104Empty username or password
105User does not exist
106Administrator account cannot be deleted
107Missing key request parameters
108Request parameter error
109Request parameters are not in legal JSON format
110Plug-in is enabled
111Plugin is closed
112Client is offline
113User already exists
114Old password is wrong
115Illegal subject