# SmartRest Response Template for Custom Operation **URL:** \ **Category:** Forum\ **Tags:** device-management, cumulocity\ **Created:** [August 18, 2025, 12:56pm UTC](https://community.cumulocity.com/t/smartrest-response-template-for-custom-operation/12619 "2025-08-18T12:56:02Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Stefan\_Veit3](https://dub1.discourse-cdn.com/flex005/user_avatar/community.cumulocity.com/stefan_veit3/32/15532_2.png) [@Stefan\_Veit3](https://community.cumulocity.com/u/Stefan_Veit3)\ **Post date:** [August 18, 2025, 12:56pm UTC](https://community.cumulocity.com/t/smartrest-response-template-for-custom-operation/12619/1 "2025-08-18T12:56:02Z")
I have a microservice which creates a custom operation for a device. The devices subscribes via MQTT to the topic s/ds. As I understand as long as I have no response template defined, the operation is not available on this topic. Now I created a SmartRest Response Template like this: 11,599,c8y\_Info,c8y\_Info.expireDate Still no message arriving on the topic. What am I missing? ---
**Author:** ![Stefan\_Witschel](https://dub1.discourse-cdn.com/flex005/user_avatar/community.cumulocity.com/stefan_witschel/32/31955_2.png) [@Stefan\_Witschel](https://community.cumulocity.com/u/Stefan_Witschel)\ **Post date:** [August 18, 2025, 1:02pm UTC](https://community.cumulocity.com/t/smartrest-response-template-for-custom-operation/12619/2 "2025-08-18T13:02:58Z")
For built-in operations like `c8y_Command` you don’t need Response templates and can just subscribe on `s/ds`. For any other custom fragment you need to define a response template and need to subscribe to `s/dc/` See here: [SmartREST 2.0 - Cumulocity documentation](https://cumulocity.com/docs/smartrest/smartrest-two/) ---
**Author:** ![Stefan\_Veit3](https://dub1.discourse-cdn.com/flex005/user_avatar/community.cumulocity.com/stefan_veit3/32/15532_2.png) [@Stefan\_Veit3](https://community.cumulocity.com/u/Stefan_Veit3)\ **Post date:** [August 18, 2025, 1:21pm UTC](https://community.cumulocity.com/t/smartrest-response-template-for-custom-operation/12619/3 "2025-08-18T13:21:37Z")
Yes, for built-in that works. For the custom one: So I would need to subscribe to s/dc/599 given my example above? Unfortunately this is not working. If I subscribe to devicecontrol/notifications I receive it. ---
**Author:** ![Korbinian\_Butz1](https://dub1.discourse-cdn.com/flex005/user_avatar/community.cumulocity.com/korbinian_butz1/32/31227_2.png) [@Korbinian\_Butz1](https://community.cumulocity.com/u/Korbinian_Butz1)\ **Post date:** [August 18, 2025, 1:59pm UTC](https://community.cumulocity.com/t/smartrest-response-template-for-custom-operation/12619/4 "2025-08-18T13:59:02Z")
Is 599 the ID of your template collection? (Also called `X-ID`) You stated you’re in a Microservice and you’re not using thin-edge. Nevertheless, the thin-edge docs [here](https://thin-edge.github.io/thin-edge.io/operate/c8y/smartrest-templates/#step-1-creating-a-smartrest-template) are giving an example on how to create a smart rest template in order to receive a custom operation (in this case under `s/dc/custom_devmgmt` ). Maybe that reference helps. ---
**Author:** ![Stefan\_Witschel](https://dub1.discourse-cdn.com/flex005/user_avatar/community.cumulocity.com/stefan_witschel/32/31955_2.png) [@Stefan\_Witschel](https://community.cumulocity.com/u/Stefan_Witschel)\ **Post date:** [August 18, 2025, 3:21pm UTC](https://community.cumulocity.com/t/smartrest-response-template-for-custom-operation/12619/5 "2025-08-18T15:21:59Z")
`599` is probably the msg-id but not the template-id as Korbinian commented already. Check the DM UI to find out the ID of your template: ![image](https://europe1.discourse-cdn.com/flex005/uploads/cumulocity/original/3X/7/d/7d38951590e00a0dbf28a12b425514098adc2c65.png) In my screen above `ID: test` ---
**Author:** ![Stefan\_Veit3](https://dub1.discourse-cdn.com/flex005/user_avatar/community.cumulocity.com/stefan_veit3/32/15532_2.png) [@Stefan\_Veit3](https://community.cumulocity.com/u/Stefan_Veit3)\ **Post date:** [August 19, 2025, 6:03am UTC](https://community.cumulocity.com/t/smartrest-response-template-for-custom-operation/12619/6 "2025-08-19T06:03:20Z")
Perfect, thank you! I indeed used the wrong ID.