Things

A Thing is an individual device identity registered in EMQX Fleets. Each Thing has a name and an MQTT Client ID, and can optionally be associated with a Thing Type that defines its schema.

Register a Thing

1. In your Fleets deployment, go to Device Management > Things.
2. Click + Register Thing.
3. Fill in the fields:
   • Name (required): A unique identifier for this device within the deployment. Used as {thingName} in MQTT topics and API calls.
   • MQTT Client ID (required): The MQTT CONNECT packet Client ID this device will use. Must match the Client ID the physical device sends when connecting to EMQX Broker.
   • Thing Type (optional): Associate this device with a Thing Type to inherit its schema.
   • Group (optional): Assign the device to a Thing Group.
   • Tags (optional): Tags to associate with this device.
4. Click Confirm.

The Thing is created with an offline status. It becomes online when a device connects to EMQX Broker using the configured MQTT Client ID.

Thing Identity Fields

Each Thing has three identity fields that serve different purposes:

Field	Used for
Thing ID	System-generated UUID; used internally and in API path parameters
Name	{thingName} in all $emqx/things/{thingName}/... MQTT topics and in API request bodies
MQTT Client ID	The MQTT CONNECT packet Client ID; used for connection lifecycle tracking (online/offline status)

Name and MQTT Client ID may be the same, but they are independent. For example, a Thing named sensor-001 might connect with MQTT Client ID sensor-001.

Thing Status

Status	Meaning
online	The device is currently connected to EMQX Broker
offline	The device is not currently connected

Status is updated automatically based on MQTT connect and disconnect events.

View Thing Details

Click a Thing name in the list to open its detail page. The top of the page shows four summary cards:

• Status: Current connection status and last online time.
• Thing Type: The associated Thing Type name and ID.
• Schema: Count of properties, events, and commands inherited from the Thing Type, shown as properties / events / commands.
• Relationships: Count of tags and Thing Groups, shown as tags / groups.

The detail page has the following tabs:

Details

Shows the Thing's identity and timestamp fields:

Field	Description
Thing ID	System-generated unique identifier
MQTT Client ID	The MQTT Client ID configured at registration
Status	Current connection status
Updated At	When the Thing record was last updated
Last Offline	When the device last disconnected
Name	The Thing name
Thing Type	The associated Thing Type
Created At	When the Thing was registered
Last Online	When the device last connected

Properties

Lists the properties defined in the Thing Type schema, with the following columns:

Column	Description
Name	Property name
Type	Data type (string, int, float, boolean, or enum)
Details	Writable status, unit, and value range (where applicable)
Description	Property description

Events

Lists the events defined in the Thing Type schema, with the following columns:

Column	Description
Name	Event name
Severity	info, warn, or error
Description	Event description

Commands

Lists the commands defined in the Thing Type schema. Click + Send Command to send a command to this device directly from the detail page.

Column	Description
Name	Command name
Type	Command type (sync)
Details	Input parameters, output parameters, and timeout
Description	Command description

Relationships

Shows the Thing Groups the device belongs to and the tags assigned to it:

• Thing Groups: A table listing the groups by Name and Description.
• Tags: Tags displayed as chips.

Jobs

Lists job executions targeting this device. Use the Status filter to narrow the list.

Column	Description
Job ID	Links to the job execution detail
Attempt	Number of execution attempts
Status	Current execution status
Shadow Version	Shadow version at the time of execution
Error Message	Error detail if the execution failed
Updated At	When the execution was last updated

Export and Import Things

To export Things as a JSON file, select one or more Things using the checkboxes, then click Export.

To import Things from a JSON file, click Import, then select the file.

Edit a Thing

1. In the Things list, click the edit icon in the Actions column.
2. Update the fields:
   • Name (required)
   • MQTT Client ID (required)
   • Thing Type (optional)
   • Group (optional): Group Tags displays the tags of the selected group and is read-only.
   • Tags (optional)
3. Click Confirm.

Filter and Search

The Things list supports filtering by:

• Thing Type: Show only Things of a specific type.
• Group: Show only Things that are members of a specific Thing Group.
• Tags: Show only Things with specific tags.
• Status: Filter by online or offline.

Use the search icon to search by Thing name.

Delete a Thing

1. In the Things list, click the delete icon in the Actions column.
2. Confirm the deletion.

Deleting a Thing removes its registration, shadow state, and group memberships.

Next Steps

• Thing Groups
• Device Shadow
• Device Query
• Connect a Device via MQTT