# Update your tracker with a device position
<a name="send-location-updates"></a>

To track your devices, you can post device position updates to your tracker. You can later retrieve these device positions or the device position history from your tracker resource.

Each position update must include the device ID, a timestamp , and a position. You may optionally include other metadata, including accuracy and up to 3 key-value pairs for your own use.

If your tracker is linked to one or more geofence collections, updates will be evaluated against those geofences (following the filtering rules that you specified for the tracker). If a device breaches a geofenced area (by moving from inside the area to outside, or vice versa), you will receive events in EventBridge. These `ENTER` or `EXIT` events include the position update details, including the device ID, the timestamp, and any associated metadata.

**Note**  
For more information about position filtering, see [Create a tracker](start-create-tracker.md).  
For more information about geofence events, see [React to Amazon Location Service events with Amazon EventBridge](location-events.md).

Use either of these methods to send device updates:
+ [Send MQTT updates](tracking-using-mqtt.md) to an AWS IoT Core resource and link it to your tracker resource.
+ Send location updates using the Amazon Location Trackers API, by using the AWS CLI, or the Amazon Location APIs. You can use the [AWS SDKs](dev-sdks.md) to call the APIs from your iOS or Android application.

------
#### [ API ]

**To send a position update using the Amazon Location APIs**

Use the `[BatchUpdateDevicePosition](https://docs.aws.amazon.com/location/latest/APIReference/API_WaypointTracking_BatchUpdateDevicePosition.html)` operation from the Amazon Location Trackers APIs. 

The following example uses an API request to post a device position update for *ExampleDevice* to a tracker *ExampleTracker*.

```
POST /tracking/v0/trackers/ExampleTracker/positions
Content-type: application/json
{
 "Updates": [
    {
    "DeviceId": "1",
    "Position": [
   -123.12245146162303, 49.27521118043802
    ],
    "SampleTime": "2022-10-24T19:09:07.327Z",
     "PositionProperties": { 
            "name" : "device1" 
         },
         "Accuracy": { 
            "Horizontal": 10
         }
    },

    {
    "DeviceId": "2",
    "Position": [
   -123.1230104928471, 49.27752402723152
    ],
    "SampleTime": "2022-10-02T19:09:07.327Z"
    },
    {
    "DeviceId": "3",
    "Position": [
    -123.12325592118916, 49.27340530543111
    ],
    "SampleTime": "2022-10-02T19:09:07.327Z"
    },
    {
    "DeviceId": "4",
    "Position": [
    -123.11958813096311, 49.27774641063121
    ],
    "SampleTime": "2022-10-02T19:09:07.327Z"
    },
    {
    "DeviceId": "5",
    "Position": [
    -123.1277418058896, 49.2765989015285
    ],
    "SampleTime": "2022-10-02T19:09:07.327Z"
    },
    {
    "DeviceId": "6",
    "Position": [
   -123.11964267059481, 49.274188155916534
    ],
    "SampleTime": "2022-10-02T19:09:07.327Z"
    }
    ]
}
```

------
#### [ AWS CLI ]

**To send a position update using AWS CLI commands**

Use the `[batch-update-device-position](https://docs.aws.amazon.com/cli/latest/reference/location/batch-update-device-position.html)` command.

The following example uses an AWS CLI to post a device position update for *ExampleDevice-1* and *ExampleDevice-2* to a tracker *ExampleTracker*. 

```
aws location batch-update-device-position \
--tracker-name ExampleTracker \
--updates '[{"DeviceId":"ExampleDevice-1","Position":[-123.123,47.123],"SampleTime":"2021-11-30T21:47:25.149Z"},{"DeviceId":"ExampleDevice-2","Position":[-123.123,47.123],"SampleTime":"2021-11-30T21:47:25.149Z","Accuracy":{"Horizontal":10.30},"PositionProperties":{"field1":"value1","field2":"value2"}}]'
```

------