FAQ: SHM and STHM are different

Just to make sure everybody’s talking about the same thing…This FAQ is for people using both the V2 classic app and the 2018 V3 app, or who have previously used the classic app and have now migrated to the new V3 app.

The security feature in the classic app is SHM, Smart Home Monitor.

The security feature in the new V3 app is STHM, SmartThings Home Monitor.

These are two completely separate pieces of code.

Security mode set or changed (or an alert dismissed) in an automation created in the classic app will only affect SHM. .

Security mode set or changed (or an alert dismissed) in an automation created in the new V3 app will only affect STHM.

So if you have rules you created in the classic app, you will never see those change the security state in the new V3 app. You have to recreate the rule using the new V3 app to see security mode changes in the V3 app.

Webcore cannot directly access the security. mode for STHM. There are two popular workarounds:

  1. create an automation that will set the security.mode based on the location.mode. But that won’t necessarily work for people who have created specialty modes like “dog walker“ or “guests.“

  2. create an automation that changes the security.mode And use a virtual switch as one of the trigger conditions. Then you can turn that virtual switch on and off as needed from a piston.


I wish this could be a sticky @JDRoberts.

It probably is worthwhile to note that if you decide to remove the classic app, you will also need to remove all of the rules that have to do with SHM in the classic app. Just deleting the app will not delete the rules in SHM in the classic app. And being that you have deleted the app, you won’t be able to clear any alarms until you reinstall the classic app.


Thanks! I made it an Automation FAQ so at least it will be easy to find again later. :wink:

Good point about deleting!

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I don’t think there is anything that Samsung isn’t doing to make this transition as complicated and frustrating as possible for people making this transition. I mean, by the law of large numbers they should get at least a couple of decisions right, shouldn’t they? Either they have really bad luck or are just choosing to not care. So sad. :cry:

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Since you seem to be quite knowledgeable on SHM vs STHM perhaps you could offer an opinion on my scenario. I use SHM via Classic on my phone. I also installed the new SmartThings on my Android media box. However STHM is unavailable (i.e. not shown under “SmartApps”) as an installation option. Everything is set up properly with the new SmartThings as far as location and all devices are recognized correctly. Can’t for the life of me figure out why STHM is missing. Where should it be coming from? You say in the FAQ " for people using both the V2 classic app and the 2018 V3 app". Is it possible that concurrent SHM and STHM results in a conflict, i.e. they’re stepping on each other’s toes? I could conceive of a Samsung implementation that persists an indicator that flags a specific app as the sole authority for arming/disarming alarms. And with such an implementation the new STHM cannot be installed until this indicator is cleared, i.e. the Classic app is unistalled. This runs counter to your assertion of “both”, but I’m running out of ideas as to what could be wrong. Has anyone actually verified that the following is consistent with your FAQ:

  1. user is using SHM via Classic on phone
  2. user installs new ST on other device
  3. user installs STHM on this other device
  4. user can arm/disarm HM via either SHM or STHM without adverse effects

Since I can’t even access STHM for installation I’m beginning to wonder if the SHM must first be removed by uninstalling Classic? This makes me nervous because if Classic cannot be reinstalled I will have painted myself into a corner. Right now STHM is unavailable, but at least SHM still works - but for how long?

It goes without saying I’m not too happy with Samsung. It seems like we users are the guinea pigs for this “migration”.

What region are you in? I believe STHM is only offered in select countries at this point.

Region is US.

Just curious… does your hub show in the new app or can you add a room in the new app (provided you have less than 20 currently)?

Yes to both. Hub shows correctly in new app and on graph web site. I created a new room in the new app and moved all the devices to that room. Everything is showing correctly in the new SmartThings - except the STHM which is nowhere to be found. In fact nothing is showing under SmartApps (where the STHM should be found according to Samsung help docs).

Do you mean the Raspberry Pi based ad-blocker? If so, no I do not. Why do you ask?

Hmm. Does the new SmartThings app use ports that Classic didn’t? I’m guessing not, but I wouldn’t put it past Samsung to pull a fast one. :roll_eyes:

Thanks. ST support has had a ticket open on this for some time. They appear as baffled as everyone else. :astonished:

Not sure its the same thing. But a couple of incidents I had about this. I switched from a V3 hub to an ADT. I had both the adt sucurity app and the STHM app. I didnt like the way they worked and I didnt know about virtual switches, so I probably gave up to quickly. But I decided to delete the STHM app and then I could not get it back. When I called ST support, they said because I went with an ADT hub. It blocked the STHM app.

Second issue, I can’t remember all the details except that in the IDE make sure you have your locations setup correctly I had two and I only need one. I ran into some issues trying to delete stuff and the second location because it was set as the “default” location. If you want to delete a location it can not be set as default. Go to the one you want to keep and edit it and change it to default. Then go to the one to delete and try to delete it ( not sure if you have to try and change it off of default first). Just my 2 cents hope it helps.