OH3: CMD API (aka: classicui/CMD=)

[oppo1967p]

Hi,
I am starting to migrating to OH3, but there are some things that I haven’t managed to understand yet.

One is the http://localhost:8080/classicui/CMD?<itemname>=<command> API.
I know it wasn’t supposed to be an official API, but as a matter of facts it has become very popular among users, especially for legacy or IoT units.

So assuming that classic UI will be removed, what is the new way of accessing items using an HTTP GET request?

I tried the JavaScript script route in /conf/html but it doesn’t seem to be working called from my units.

thanks

[hmerk (Hans-Jörg Merk)]

As this was never supported officially and ClassicUI has been removed, you need to use REST api calls.
Please check the developer tools menu in MainUI.
You can test the calls and will see how a proper curl command would look like.

[oppo1967p]

Thanks for your reply, but my units do not support POST requests.
So REST API is not an option.

Many users have raised this question in the past and they have been suggested to use the http://localhost:8080/classicui/CMD?<itemname>=<command> API.

Now that this API has been removed in version 3, another option should be given or many setups will never work.

[hmerk (Hans-Jörg Merk)]

As said, this was never an official optio, but a leftover from jetty server. There will be no other option than using REST.

[oppo1967p]

@hmerk

As said, this was never an official optio, but a leftover from jetty server.

I know that (I wrote it in my first post), but according to my search only in this forum, there are plenty of topics covering this API and many users that are using this “non-official” feature.
As you know there are units that do not support POST requests but just simple HTTP GET requests.
What is the solution?

[hmerk (Hans-Jörg Merk)]

Open a feature request. If this will be denied, there is no solution inside openHAB.

[rlkoshak (Rich Koshak)]

In addition to the fact that the CMD GET request doesn’t exist any more, you also have to deal with authentication now too. So even if it were supported, you’d have to enable and use BasicAuth or create an access token and configure your calling scripts to use that. Maybe that’s what went wrong with your attempts in conf/html?

I’ve not tried to do this sort of thing on OH 3 yet but I did something like this in my OAuth2 using just OH Rules and myopenhab.org. But I’m certain this will be behind the authentication/authorization in OH 3 which needs to be taken into account.

@oppo1967p

So assuming that classic UI will be removed, what is the new way of accessing items using an HTTP GET request?

Keep in mind though that you are not accessing the Item with that call. You are commanding the Item. You can still access and see the Item’s state using a GET request.

@oppo1967p

I know that (I wrote it in my first post), but according to my search only in this forum, there are plenty of topics covering this API and many users that are using this “non-official” feature.

I doubt you will find many if any of those posts to be less than two years old.

[rossko57]

@oppo1967p

Now that this API has been removed in version 3, another option should be given or many setups will never work.

You can of course continue to use OH2

[HaKuNa (Remo M)]

I wrote a helper for a device with a limited action url support.

HaKuNaCH/dingzOpenHabHelperApi

It accepts GET requests to update items and can deal with the OH3 API token.
It uses PUT to update openhab items (PUT /rest/items/itemname/state) -> like “postUpdate” in rules
But it would be quite easy to also support POST requests (POST /rest/items/itemanme) -> like “sendCommand” in rules

[John_Siemon]

I just replaced classicui with basicui and it seems to work fine for me. I’ve been using basicui instead of classicui even with OH2.5.x and it continues to work for me with OH3. I just hope by pointing this out it does not result in it being removed in the next update. It might be worth a try since it is straight forward to implement and test.

This is an example of a command that I use in my DemoPAD remote whereby I use OH3 as a broker between DemoPAD and a Shelly switch, since DemoPAD does not have a driver for Shelly but OH3 does.

GET /basicui/CMD?vBay1GarageLight=OFF HTTP/1.1\x0D\x0AHost: 192.168.x.yyy\x0D\x0A

[hmerk (Hans-Jörg Merk)]

@John_Siemon

I just replaced classicui with basicui and it seems to work fine for me.

Please bear in mind you are using it at your own risk. It might stop working without any announcement, as it is not a feature.

[oppo1967p]

@HaKuNa

i wrote a helper for a device with a limited action url support.

@John_Siemon

I just replaced classicui with basicui and it seems to work fine for me. I’ve been using basicui instead of classicui even with OH2.5.x and it continues to work for me with OH3.

Thanks for your answer. You have been very kind.
I will try them out and let you know.

@hmerk

Please bear in mind you are using it at your own risk. It might stop working without any announcement, as it is not a feature.

Well, this is exactly the typical answer that doesn’t help the community to solve its problem.
It’s very easy to say “Use OH2” or “It might stop working at anytime” instead of understanding that some users have some needs and try to solve them out. Sorry to be so hard.

Just for your information, I have contributed with donations to this project and also developed some changes in a binding.

@rlkoshak

I doubt you will find many if any of those posts to be less than two years old

As a matter of fact, two users have already replied in just few hours with their solution, so I think that this “unofficial” feature is more used that you think.

[hmerk (Hans-Jörg Merk)]

@oppo1967p

Well, this is exactly the typical answer that doesn’t help the community to solve its problem.
It’s very easy to say “Use OH2” or “It might stop working at anytime” instead of understanding that some users have some needs and try to solve them out. Sorry to be so hard.

Nothing you must excuse for, I can handle such answers

Yes, my answer is not solving YOUR issue, but for openHAB, this is not an issue.
It was already mentioned 2015 and later, not to use the CMD servlet :

Rest PUT not working in OH2

This is part of the Classic UI and still exists in OH2 as well. But it was never meant as an API for external integration, the REST API is indeed the way to go. It does not actually control / send a command You can find the docs here: https://www.eclipse.org/smarthome/rest/index.html PUT does on MyItem/state does a status update, POST on MyItem sends a command. TOGGLE, which seems to have been added to OH1 Toggle is no valid command, the CMD servlet only used that as a convenience func…

[SOLVED] Use URL to manipulate items in OH2?

Well, it mentions that “the Classic UI URL has changed from /openhab.app to /classicui/app”. Note that the CMD servlet is an internal part of the Classic UI that is NOT meant to be used by anybody else (although it is of course possible). But as it is not an official feature, I would claim it should also not be documented. The way to interact with external systems is clearly the REST API.

@oppo1967p

Just for your information, I have contributed with donations to this project and also developed some changes in a binding.

Thanks for your donations, we really appretiate it. But should this change my opinion? No, don’t think so.

[oppo1967p]

@John_Siemon

I just replaced classicui with basicui and it seems to work fine for me. I’ve been using basicui instead of classicui even with OH2.5.x and it continues to work for me with OH3.

This works! Thanks.

[oppo1967p]

@rlkoshak

I doubt you will find many if any of those posts to be less than two years old.

Here is another user interested…

Replacement of classicui/CMD

Hello there, in OH2 I´ve used to use classicui/CMD pass an String-Value to an Item via HTTP GET Request like http://192.168.X.X:8080/classicui/CMD?String=VAR How can this be done in OH3? I have already made several attempts with the HTTP binding, unfortunately unsuccessful. Manipulating the Var with curl works but I need to to this by user clicking on a URL. Thank you very much!

[StefanMUC (Stefan)]

@oppo1967p

Well, this is exactly the typical answer that doesn’t help the community to solve its problem.

Yeah, but even ideomaticly from HTTP perspective it’s wrong for a GET request to change something. GETs are just for reading, POST, PUT and other ones are allowed to change things - but not GET

So I also would advise you to strive for a proper solution than to stick to the old stuff that once used to work (but never was supposed to work).

[oppo1967p]

Hi Stefan,
I agree with you 100%.
But unfortunately there are legacy devices that have only this option (GET) to interact with openHAB.

[Oliver2 (Oliver)]

True. I have my Mobotix Camera configured that way to send information and events via http/get. Only the latest models support http/post but not older ones.

[TheSwitcher (Wacka Dack)]

This worked for me too.
I am integrating an Auerswald PBX with the CMD servlet. Dialing a special phone number triggers the PBX to call a so called “action URL” on the Rest API of OH. It is just calling a URL, without POST/GET syntax and no authentication.

Worked great in OH2 times, and continues to work on OH3, but I am aware that this is kind of a dirty solution built on a unofficial feature and may break in the future without notice.

I am also wondering if this is a backdoor, imposing a security issue because it bypasses OH3 authentication. There is no Basic Auth or API token coded into the action URL and it sends commands to OH.

[rlkoshak (Rich Koshak)]

@TheSwitcher

I am also wondering if this is a backdoor, imposing a security issue because it bypasses OH3 authentication. There is no Basic Auth or API token coded into the action URL and it sends commands to OH.

The security model for OH 3 is to protect administration functions behind authentication and authorization. Day-to-day use is not protected. Sending commands to Items counts as day-to-day so it is not a violation of OH3’s security model. If you want to protect even the day-to-day stuff, you have to put OH behind a reverse proxy.