MQTT v5 added first-class request/response support (Response Topic + Correlation Data properties), but today doing an MQTT request in Node-RED means hand-rolling it: publish on one topic, subscribe on another, generate and track correlation IDs, keep a map of in-flight requests keyed by correlation …

[image] Steve-Mcl: I love using the $ ENV typed input for things like {SITE_ID}/{DEPT_ID}/{SERVER_ID}/status Can you do that ? I thought the env syntax only allowed a single variable name - not compositions ? when did that change ? Do you need to worry about possible queue depths at all wh…

[image] dceejay: Can you do that ? I thought the env syntax only allowed a single variable name - not compositions It definitely works for a a single composite replacement but you now have me doubting multiples. From the help: if ${} is present, it will substitute the corresponding environ…

[image] dceejay: Do you need to worry about possible queue depths at all while waiting for (non)responses It occurred to me during development then I completely forgot to look in to it. Any pointers to give me a head start (a code link, a variable name, even a current node that does this) @d…

Will you be able to detect the circumstance where the broker (Mosquitto) supports MQTT V5 but the remote server (eg Tasmota) does not?

What is the use case for such feature? Just wondering why polling should be needed...

Is the idea to add another core node or to do this with a separate mqttv5-request-response node package? Can't you create such a node package and leave it at that? Why and what is the reasoning to add a core node for this? The fewer core nodes, the less the chance that something breaks in core and …

Hey @jbudd I dont use Tasmota but I did look into this for you. At this time, unless Tasmota upgrades to an MQTT v5 lib, not at this time. There is an open issue here but no one has suggested an alternative lib. A quick search reveals more than one candidate e.g. mqtt5nano , ESP32_MQTTv5 , H4AsyncMQ…

[image] krambriw: What is the use case for such feature? In a distributed system where data or operations live on separate edge devices, matching asynchronous responses back to the original triggering flow is incredibly clunky in MQTT v3.1.1. A classic use case is on-demand commanding. Imagi…

[image] gregorius: Is the idea to add another core node or to do this with a separate mqttv5-request-response node package? Core node. It shares deep functionality with the existing MQTT core codebase, and I want it to be a first-class citizen. [image] gregorius: Can't you create such a …

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We have http-request, tcp-request, serial-request - any objections to an mqtt-request?

Core Development Feature Requests

dceejay 5 July 2026 21:38 5

It came up recently (which is why I remembered) over here - Help with `delay` node set to `rate limit` - #16 by dceejay

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We have http-request, tcp-request, serial-request - any objections to an mqtt-request?

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