# Deprecate a thing type


Thing types are immutable. They can't be changed after they are defined. You can, however, deprecate a thing type to prevent users from associating any new things with it. All existing things associated with the thing type are unchanged.

To deprecate a thing type, use the **DeprecateThingType** command:

```
$ aws iot deprecate-thing-type --thing-type-name "myThingType"
```

You can use the **DescribeThingType** command to see the result:

```
$ aws iot describe-thing-type --thing-type-name "StopLight":
```

```
{
    "thingTypeName": "StopLight",
    "thingTypeProperties": {
        "searchableAttributes": [
            "wattage",
            "numOfLights",
            "model"
        ],
        "thingTypeDescription": "traffic light type",
    },
    "thingTypeMetadata": {
        "deprecated": true,
        "creationDate": 1468425854308,
        "deprecationDate": 1468446026349
    }
}
```

Deprecating a thing type is a reversible operation. You can undo a deprecation by using the `--undo-deprecate` flag with the **DeprecateThingType** CLI command:

```
$ aws iot deprecate-thing-type --thing-type-name "myThingType" --undo-deprecate
```

You can use the **DescribeThingType** CLI command to see the result:

```
$ aws iot describe-thing-type --thing-type-name "StopLight":
```

```
{
    "thingTypeName": "StopLight",
    "thingTypeArn": "arn:aws:iot:us-east-1:123456789012:thingtype/StopLight",
    "thingTypeId": "12345678abcdefgh12345678ijklmnop12345678"
    "thingTypeProperties": {
        "searchableAttributes": [
            "wattage",
            "numOfLights",
            "model"
        ],
        "thingTypeDescription": "traffic light type"
    },
    "thingTypeMetadata": {
        "deprecated": false,
        "creationDate": 1468425854308,
    }
}
```