# MQTT quick reference
Source: https://cumulocity.com/docs/smartrest/quick-reference/
Sector: Device management & connectivity
Release: Latest
#### Connection {#connection}
* CONNECT d:1235:myDevice_10 acme/device_1235 \
Connect the device with serial "1235" and default template myDevice_10 to tenant "acme" and user "device_1235".
#### Topics {#topics}
Publish
* PUBLISH s/us - Send a static template.
* PUBLISH s/us/5678 - Send a static template as child "5678".
* PUBLISH s/ud - Send a message using the default template (myDevice_10).
* PUBLISH s/ud/5678 - Same as above, but as child "5678".
* PUBLISH s/uc/myCommon_10 - Send a message using myCommon_10 template.
* PUBLISH s/uc/myCommon_10/5678 - Same as above, but as child "5678".
Subscribe
* SUBSCRIBE s/ds - Receive static commands.
* SUBSCRIBE s/dd - Receive commands using the default template (myDevice_10).
* SUBSCRIBE s/dc/myCommon_10 - Receive commands using the myCommon_10 template.
* SUBSCRIBE s/e - Receive error messages.
#### Topic format {#topic-format}
`/[/][/]`
where:
* `` can be s (persistent), t (transient), q (quiescent) and c (CEP), see [Processing mode](https://cumulocity.com/docs/smartrest/smartrest-one/#processing-mode) for more information.
* `` can be u (upstream from the device), d (downstream to the device) or e (error).
* `` can be s (static), c (custom, device-defined), d (default), t (template) or cr (credentials).
#### Device registration {#device-registration}
* CONNECT 1234 management/devicebootstrap
* SUBSCRIBE s/dcr
* PUBLISH s/ucr
* PUBLISH s/ucr
* ...
* 70,tenant,username,password
#### Template registration {#template-registration}
* PUBLISH s/ut/myCommon_10
* 10,999,POST,MEASUREMENT,,c8y_MyMeasurement;;c8y_MyMeasurement.M.value,NUMBER,...
10,msgId,api,method,response,type,time,custom1.path,custom1,type,custom1.value
#### Templates {#templates}
See the [templates quick reference](https://cumulocity.com/docs/smartrest/mqtt-static-templates) for an overview of the available MQTT static templates.