Edit API Node to update an entitiy attributes from different flows

[brokenarrow03]

Hello,

I am wanting to use the Edit API node to update an entitiy in HA. I would like to update the entity from multiple places in node red and am having some trouble with building the mustache payload in a node red function node.

Example.

Device 1 is a system fan. the entity is sensor.systemfan_1, simple enough, the status is a boolean T/F so I display OK or FAIL respectively, but I want to update an attribute "RPM" from another flow. I am using the function node in node red to send the data to the Edit API node, but I dont want to have to update the status "OK" just to update the attribute RPM if that makes sense?

Function 1...

msg.payload = {
data: {
state: (msg.payload.Fans[0].Status.Health),
attributes: {
fanName: (msg.payload.Fans[0].FanName),
icon: 'mdi:fan'
}
}
};
return msg;

Function 2...

msg.payload = {
data: {
attributes: {
fanName: (msg.payload.fan1rpm)
}
}
};
return msg;

Any suggestions are welcome! Thanks in advance!

[false200]

@brokenarrow03 yeah you absolutely do not need to touch the OK/FAIL state every time you just want to push RPM. The main thing tripping you up is probably the payload shape, and one detail about how attributes actually get written in Home Assistant.

If you are wiring into the Sensor node (the blue ha-sensor node that owns sensor.systemfan_1), the payload should sit directly on msg.payload, not wrapped inside data. The data wrapper is for the API node when you are sending a raw websocket command. Mixing those two up is a really common gotcha.

Also in Function 2 you are writing the RPM value into fanName. That should be its own attribute, something like rpm.

---

Flow 1 (health/status)

let attrs = flow.get('fan1_attrs') || { icon: 'mdi:fan' };

attrs.fanName = msg.payload.Fans[0].FanName;

flow.set('fan1_attrs', attrs);

msg.payload = {
    state: msg.payload.Fans[0].Status.Health ? 'OK' : 'FAIL',
    attributes: attrs
};

return msg;

---

Flow 2 (RPM only, no state change)

let attrs = flow.get('fan1_attrs') || { icon: 'mdi:fan' };

attrs.rpm = msg.payload.fan1rpm;

flow.set('fan1_attrs', attrs);

msg.payload = {
    attributes: attrs
};

return msg;

---

Wire both function nodes into the same Sensor node. Set Input Override to allow or merge on that node.

The reason for the flow.get / flow.set bit is important. Home Assistant replaces the full attributes object on each update, it does not merge in only the keys you send. So if Flow 2 fires with just { rpm: 1200 } and nothing else, you can accidentally wipe fanName and icon that Flow 1 set earlier. Keeping a small copy in flow context and merging before each send avoids that.

On the HA side, the companion integration is built so state only changes when state is actually in the message. Attributes-only updates are supported. So Flow 2 does not need to resend OK/FAIL.

---

A few other small things worth checking

• Make sure both flows hit the Sensor node that created the entity, not a random API node pointed at the entity id, unless you really need the low-level websocket route.

• If Status.Health comes through as the strings "T" / "F" instead of real booleans, map those explicitly before you set state.

• If you do want the API node route instead, you need nodered/entity with the correct server_id and node_id from your entity config node, and you still need to send the full merged attributes object for the same reason as above. For what you are doing, the Sensor node plus flow context is the simpler path.

Hope that gets you unstuck.

[brokenarrow03]

Oh cool! I will give it a go! Thanks!

Yea so I am using the Websocket/API node, but this sounds much easier. As far as the fanname/rpm my bad on my copy/paste!

Thanks!

[false200]

Sounds good.

[brokenarrow03]

Hey just wanted to update you! This did work so thanks for the pointers. The only thing I had to change was the flow variable. I had to set it to a global variable, and due to this I changed the attrs variable to be a bit more descriptive so I woulndt end up with duplicate "fans" or something like that!

Thanks again!