Fields and Field Masks

Field Masks

The Things Stack APIs use field masks to specify a subset of fields that should be returned by a reading request, or to specify fields that should be updated in a writing request. API request messages which contain a field_mask field operate this way - for example, GetEndDeviceRequest, or UpdateApplicationRequest, and most Get, List, Set, and Update requests. By default, these API requests will not return or update most fields, unless they are specified in a field mask.

The following fields are always returned:

• Fields containing id
• created_at
• updated_at
• deleted_at

All other fields are not returned and not updated, unless specified. Fields that are empty or zero are not returned, even if they are specified in a field mask.

Fields and Field Masks in HTTP Queries

GET Requests

Fields may be specified in HTTP GET requests by appending them as query string parameters. For example, to request the name, description, and locations of devices in an EndDeviceRegistry.Get request, add these fields to the field_mask field. To get this data for device dev1 in application app1:

curl --location --header "Authorization: Bearer NNSXS.XXXXXXXXX" "https://thethings.example.com/api/v3/applications/app1/devices/dev1?field_mask=name,description,locations"

This will return the following:

{
   "ids":{
      "device_id":"dev1",
      "application_ids":{
         "application_id":"app1"
      },
      "dev_eui":"46CF72F61862CBB0",
      "join_eui":"66209794D18AE087"
   },
   "created_at":"2020-07-31T12:17:51.645Z",
   "updated_at":"2021-07-20T14:14:56.318Z",
   "name":"device-name",
   "description":"device-description",
   "locations":{
      "user":{
         "latitude":52.51622086393074,
         "longitude":13.39075966780985,
         "source":"SOURCE_REGISTRY"
      }
   }
}

Without the field masks specified, this request would not return the name, description, and locations fields:

{
   "ids":{
      "device_id":"ben-things-uno",
      "application_ids":{
         "application_id":"tti-playground"
      },
      "dev_eui":"46CF72F61862CBB0",
      "join_eui":"66209794D18AE087"
   },
   "created_at":"2020-07-31T12:17:51.645Z",
   "updated_at":"2020-07-31T12:17:51.645Z"
}

PUT Requests

PUT requests can be used to update entities by supplying the object as JSON data. To update fields, the field mask must also be specified in the JSON object (query parameters do not work for PUT requests). The field mask has the following format:

{
  "field_mask": {
      "paths": [
        "ids.device_id",
        "name",
        "description"
      ]
    }
}

Where ids.device_id, name, and description are fields to be updated.

For example, to update the name field of device dev1 in application app1with an EndDeviceRegistry.Update request:

curl --location \
  --header 'Authorization: Bearer NNSXS.XXXXXXXXX' \
  --header 'Content-Type: application/json' \
  --request PUT \
  --data-raw '{
   "end_device":{
      "name":"device-name",
      "description":"device-description"
   },
    "field_mask": {
      "paths": [
        "name"
      ]
    }
  }' \
  'https://thethings.example.com/api/v3/applications/app1/devices/dev1'

This request will update the name field of the device, but will not update the description field because it is not specified in the field_mask object. The following will be returned as confirmation:

{
   "ids":{
      "device_id":"dev1",
      "application_ids":{
         "application_id":"app1"
      },
      "dev_eui":"46CF72F61862CBB0",
      "join_eui":"66209794D18AE087"
   },
   "created_at":"2020-07-31T12:17:51.645Z",
   "updated_at":"2021-07-20T15:04:26.339Z",
   "name":"device-name"
}

To update both the name and description fields, the following request could be made:

curl --location \
  --header 'Authorization: Bearer NNSXS.XXXXXXXXX' \
  --header 'Content-Type: application/json' \
  --request PUT \
  --data-raw '{
   "end_device":{
      "name":"device-name",
      "description":"device-description"
   },
    "field_mask": {
      "paths": [
        "name",
        "description",
      ]
    }
  }' \
  'https://thethings.example.com/api/v3/applications/app1/devices/dev1'

This would return the following confirmation:

{
   "ids":{
      "device_id":"dev1",
      "application_ids":{
         "application_id":"app1"
      },
      "dev_eui":"46CF72F61862CBB0",
      "join_eui":"66209794D18AE087"
   },
   "created_at":"2020-07-31T12:17:51.645Z",
   "updated_at":"2021-07-20T15:04:26.339Z",
   "name":"device-name",
   "description": "device-description",
}

POST Requests

Some endpoints require a message to be sent as part of the request. For example, to request an Event Stream, you must POST a StreamEventsRequest message:

curl --location \
  --header 'Authorization: Bearer NNSXS.XXXXXXXXX' \
  --header 'Content-Type: application/json' \
  --request POST \
  --data-raw '{
    "identifiers":[{
        "device_ids":{
            "device_id":"dev1",
            "application_ids":{"application_id":"app1"}
        }
    }]
  }' \
  'https://thethings.example.com/api/v3/events'