# Mqtt Multiple Inputs to one Json Object or Array

**URL:** <https://discourse.nodered.org/t/mqtt-multiple-inputs-to-one-json-object-or-array/98244>\
**Category:** General\
**Created:** [21 July 2025 20:21 UTC](https://discourse.nodered.org/t/mqtt-multiple-inputs-to-one-json-object-or-array/98244 "2025-07-21T20:21:48Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Starfoxfs](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/starfoxfs/32/69119_2.png) [@Starfoxfs](https://discourse.nodered.org/u/Starfoxfs)\
**Post date:** [21 July 2025 20:21 UTC](https://discourse.nodered.org/t/mqtt-multiple-inputs-to-one-json-object-or-array/98244/1 "2025-07-21T20:21:48Z")

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Hi,

i have a OpenDTU Mqtt Input with Multiple Numbers in the msg.payload but no exact Identity. The Identity of each payload is in the Topic.

I want to add all togehter in a function and add the Identity to it like Voltage, Current etc.

How to do this ?

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**Author:** ![jbudd](https://avatars.discourse-cdn.com/v4/letter/j/5f8ce5/32.png) [@jbudd](https://discourse.nodered.org/u/jbudd)\
**Post date:** [21 July 2025 20:35 UTC](https://discourse.nodered.org/t/mqtt-multiple-inputs-to-one-json-object-or-array/98244/2 "2025-07-21T20:35:17Z")

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The normal Node-red way would be to use a Join node in manual mode, using msg.topic to distinguish each input.

For example, if you have messages with msg.topic == "current" and "voltage", you can set the join node to join after 2 message parts.

> [@Starfoxfs](#):
>
> I want to add all together in a function and add the Identity to it like Voltage, Current etc.

Why do you want to do it in a function?  
Are you just reaching for a function node because you think it's needed, or is there some other reason?

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<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [21 July 2025 20:46 UTC](https://discourse.nodered.org/t/mqtt-multiple-inputs-to-one-json-object-or-array/98244/3 "2025-07-21T20:46:00Z")

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See also [this article in the cookbook](https://cookbook.nodered.org/basic/join-streams) for an example of how to join messages into one object.

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<div class="post-metadata">

**Author:** ![Starfoxfs](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/starfoxfs/32/69119_2.png) [@Starfoxfs](https://discourse.nodered.org/u/Starfoxfs)\
**Post date:** [22 July 2025 07:58 UTC](https://discourse.nodered.org/t/mqtt-multiple-inputs-to-one-json-object-or-array/98244/4 "2025-07-22T07:58:29Z")

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Thanks thats it 😀

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**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [5 August 2025 07:58 UTC](https://discourse.nodered.org/t/mqtt-multiple-inputs-to-one-json-object-or-array/98244/5 "2025-08-05T07:58:49Z")

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