Insert variable inside a json array

Hi, I have this json:

{
    "transition": "5",
    "brightness": "100",
    "hs_color": [
        <HERE>,
        100
    ]
}

What I want is to replace <HERE> with a number that comes from msg.payload and it has to be without quotes of course. How would I do that?

use a function node...

msg.payload = {
    "transition": "5",
    "brightness": "100",
    "hs_color": [
        msg.payload,
        100
    ]
}
return msg;

that all depends on what msg.payload contains.

I cannot use a function node, the json is already inside the node that has a data parameter. All I can do is to write json in that box.

why not?

You do realise we have no idea what node you are talking about and no idea that "All I can do is to write json in that box" - unless you show us or tell us?

Share a screenshot and tell us what node you are talking about please...

Actually there's an option to pass the complete json. The node I'm talking about is the homeassistant call service. Switch Data to expression is the solution + using the function node of course.

Home assistant nodes usually allow JSONata.
If so use

{
    "transition": "5",
    "brightness": "100",
    "hs_color": [
       $$.payload,
        100
    ]
}

Unexpected '$' :frowning:

Vague response. you are using json you need to use JSONata. please post your flow and images of home assistant node config.

This works as a JSONata expression in a change node, I cannot test with HA.

[{"id":"2d284e1347441e18","type":"inject","z":"08a01d3d77d9d931","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"111","payloadType":"num","x":250,"y":300,"wires":[["34c6580345abe8b6"]]},{"id":"34c6580345abe8b6","type":"change","z":"08a01d3d77d9d931","name":"","rules":[{"t":"set","p":"js","pt":"msg","to":"{     \"transition\": \"5\",     \"brightness\": \"100\",     \"hs_color\": [         payload,         100     ] }","tot":"jsonata"}],"action":"","property":"","from":"","to":"","reg":false,"x":410,"y":300,"wires":[["24a7a0ac88579d41"]]},{"id":"24a7a0ac88579d41","type":"debug","z":"08a01d3d77d9d931","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":590,"y":300,"wires":[]}]