# Capability Schema Documentation **URL:** \ **Category:** Writing Device Types\ **Created:** [April 11, 2022, 8:20am UTC](https://community.smartthings.com/t/capability-schema-documentation/241530 "2022-04-11T08:20:54Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![blueyetisoftware](https://yyz2.discourse-cdn.com/smartthings/user_avatar/community.smartthings.com/blueyetisoftware/32/143828_2.png) [@blueyetisoftware](https://community.smartthings.com/u/blueyetisoftware)\ **Post date:** [April 11, 2022, 8:20am UTC](https://community.smartthings.com/t/capability-schema-documentation/241530/1 "2022-04-11T08:20:54Z")
Where can we find documentation for all of the fields in the capability yml/json files? This document is pretty useful but doesn’t seem exhaustive. At the moment, I am trying to figure out what the field `additionalProperties` is used for? You can see it in the sample capability. I am also curious about how the `schema.type` is used as well as the `required` array. These are pretty much in all capabilities, but I’m not sure what they control in terms of behavior. ```auto "attributes": { "colorTemperature": { "schema": { "type": "object", "properties": { "value": { "type": "integer", "minimum": 2600, "maximum": 9000 }, "unit": { "type": "string", "enum": [ "K" ], "default": "K" } }, "additionalProperties": false }, "required": [ "value" ] } } ``` > **[Capabilities | SmartThings Developers](https://developer-preview.smartthings.com/docs/devices/capabilities/capabilities/)** > > Visit the Production Capabilities page to find a full list of production Capabilities maintained by SmartThings. ---
**Author:** ![nayelyz](https://avatars.discourse-cdn.com/v4/letter/n/59ef9b/32.png) [@nayelyz](https://community.smartthings.com/u/nayelyz)\ **Post date:** [April 11, 2022, 4:16pm UTC](https://community.smartthings.com/t/capability-schema-documentation/241530/2 "2022-04-11T16:16:12Z")
There are more details about it in the API reference [for capabilities](https://developer-preview.smartthings.com/docs/api/public#operation/createCapability). ![image](https://global.discourse-cdn.com/smartthings/original/3X/5/c/5c63bf668333998fc5817cfbb69280e5592ec551.png) `schema.type` of an attribute is set to “object” because it is formed by the “value” and “unit” properties. In the case of capability commands, the `schema.type` depends on the type of argument that the command receives (“string”, “number”; in the case of `setColor` in [ColorControl](https://developer-preview.smartthings.com/docs/devices/capabilities/capabilities-reference#colorControl), the type is “object” because the argument is a `color_map`) `required` is used to define which property is mandatory for the attribute. By default, only “value” is required but, if we add “unit”, we would need to send both in the capability events, otherwise, we’ll receive an error. An example of that is [temperatureMeasurement](https://developer-preview.smartthings.com/docs/devices/capabilities/capabilities-reference#temperatureMeasurement). ---
**Author:** ![blueyetisoftware](https://yyz2.discourse-cdn.com/smartthings/user_avatar/community.smartthings.com/blueyetisoftware/32/143828_2.png) [@blueyetisoftware](https://community.smartthings.com/u/blueyetisoftware)\ **Post date:** [April 11, 2022, 8:47pm UTC](https://community.smartthings.com/t/capability-schema-documentation/241530/3 "2022-04-11T20:47:00Z")
@nayelyz I’m still not clear on `additionalProperties`. Does that mean that if I define an enum, a driver would be able to set a value that is not in that enum? What would it mean for non-enum types? ---
**Author:** ![nayelyz](https://avatars.discourse-cdn.com/v4/letter/n/59ef9b/32.png) [@nayelyz](https://community.smartthings.com/u/nayelyz)\ **Post date:** [April 11, 2022, 8:55pm UTC](https://community.smartthings.com/t/capability-schema-documentation/241530/4 "2022-04-11T20:55:12Z")
> [@blueyetisoftware](#): > > Does that mean that if I define an enum, a driver would be able to set a value that is not in that enum? My understanding is that it refers to other properties _of the attribute_ that are not “value” or “unit”, which means it is not related to the “value” set for the capability and its type. I’ll check with the team if they can provide more details about it. BTW, if you define the property `value.enum` and send an event with a different value, it won’t be saved, is that what you meant? ---
**Author:** ![blueyetisoftware](https://yyz2.discourse-cdn.com/smartthings/user_avatar/community.smartthings.com/blueyetisoftware/32/143828_2.png) [@blueyetisoftware](https://community.smartthings.com/u/blueyetisoftware)\ **Post date:** [April 11, 2022, 9:39pm UTC](https://community.smartthings.com/t/capability-schema-documentation/241530/5 "2022-04-11T21:39:50Z")
> [@nayelyz](#): > > if you define the property `value.enum` and send an event with a different value, it won’t be saved, is that what you meant? Yes. I have seen other drivers that display a list type, but somehow are changing the label to show text that is not in that enum. They must be doing something tricky with the presentation. ---
**Author:** ![nayelyz](https://avatars.discourse-cdn.com/v4/letter/n/59ef9b/32.png) [@nayelyz](https://community.smartthings.com/u/nayelyz)\ **Post date:** [April 11, 2022, 9:44pm UTC](https://community.smartthings.com/t/capability-schema-documentation/241530/6 "2022-04-11T21:44:32Z")
> [@blueyetisoftware](#): > > somehow are changing the label to show text that is not in that enum Aaah, I think I got you, so, a value is saved for the capability but in the app, you see a “pretty/human-readable” text. That’s thanks to the “alternatives” property set in the presentation where “key” is the capability value and “value” is the “label”. Just a head’s up, there’s an issue with the alternatives in the `dashboard.state`: when you send a value that doesn’t have an alternative configured. ([Here’s](https://community.smartthings.com/t/st-edge-attribute-wont-update-to-non-alternatives-value-after-first-alternatives-match/240947/6) a post about that) ---
**Author:** ![blueyetisoftware](https://yyz2.discourse-cdn.com/smartthings/user_avatar/community.smartthings.com/blueyetisoftware/32/143828_2.png) [@blueyetisoftware](https://community.smartthings.com/u/blueyetisoftware)\ **Post date:** [April 11, 2022, 10:05pm UTC](https://community.smartthings.com/t/capability-schema-documentation/241530/7 "2022-04-11T22:05:12Z")
I wasn’t referring to alternatives, but that is helpful to note. I have seen a driver actually put a dynamic value into a list display type in the detail view. It was a value built by the driver that didn’t exist in the enum nor in the alternatives. I would need to find it again to get more details. ---
**Author:** ![nayelyz](https://avatars.discourse-cdn.com/v4/letter/n/59ef9b/32.png) [@nayelyz](https://community.smartthings.com/u/nayelyz)\ **Post date:** [April 11, 2022, 10:26pm UTC](https://community.smartthings.com/t/capability-schema-documentation/241530/8 "2022-04-11T22:26:40Z")
> [@blueyetisoftware](#): > > dynamic value into a list display type in the detail view I’ve seen that, if you send an unknown value, it is still shown but the value is not added to the list, which means it isn’t dynamic unless they’re changing the presentation… Please, let me know if you figure out more, it could be a bug… ---
**Author:** ![nayelyz](https://avatars.discourse-cdn.com/v4/letter/n/59ef9b/32.png) [@nayelyz](https://community.smartthings.com/u/nayelyz)\ **Post date:** [April 13, 2022, 5:18pm UTC](https://community.smartthings.com/t/capability-schema-documentation/241530/9 "2022-04-13T17:18:49Z")
> [@blueyetisoftware](#): > > I’m still not clear on `additionalProperties` . Following up on this, the `additionalProperties` value cannot be set to `true`, we receive the following error if we try: ```auto { "requestId": "804BCEF9-D153-....", "error": { "code": "ConstraintViolationError", "message": "The request is malformed.", "details": [ { "code": "UnprocessableEntityError", "target": "capabilityId.attributes.attrName.schema.additionalProperties", "message": "capabilityId.attributes.attrName.schema.additionalProperties: does not have a value in the enumeration [false]", "details": [] } ] } } ``` This means, only the properties of `value`, `unit`, and `data` are available for the attribute schema. ---
**Author:** ![nmpu](https://avatars.discourse-cdn.com/v4/letter/n/a87d85/32.png) [@nmpu](https://community.smartthings.com/u/nmpu)\ **Post date:** [April 13, 2022, 6:58pm UTC](https://community.smartthings.com/t/capability-schema-documentation/241530/10 "2022-04-13T18:58:25Z")
I’ve done a lot of experimentation with the `list` display type. It’s not possible to dynamically change the `list` entries. You can dynamically _filter_ the `list` entries, but all possibilities must be known prior to packaging the driver. Further, the filter is only applied when the `list` is initially populated. This means you need to leave `detailView` and return in order to see any changes. You _can_ populate the state field to the left of the gear with any string you want. The `mediaPresets` capability can be populated dynamically. The disadvantage is that nothing else about the presentation can be modified. The state area and label are fixed. ---
**Author:** ![blueyetisoftware](https://yyz2.discourse-cdn.com/smartthings/user_avatar/community.smartthings.com/blueyetisoftware/32/143828_2.png) [@blueyetisoftware](https://community.smartthings.com/u/blueyetisoftware)\ **Post date:** [April 13, 2022, 11:52pm UTC](https://community.smartthings.com/t/capability-schema-documentation/241530/11 "2022-04-13T23:52:05Z")
Thanks. These responses are helpful. I think being able to set the list ‘state’ should do the trick. I’m guess this is also why the ‘modes’ and ‘scenes’ capabilities are not live yet in ST. The possible values need to be determined at runtime, and the platform won’t allow it yet.