> For the complete documentation index, see [llms.txt](https://sensecap.gitbook.io/doc/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://sensecap.gitbook.io/doc/data-openstream-api/quick-start.md).

# Data OpenStream API Quickstart

### Setup

* Install or [download](https://mosquitto.org/download/) Mosquitto.

### Credentials <a href="#credentials" id="credentials"></a>

Browse [https://sensecap.seeed.cc](https://wiolora.seeed.cc),  navigate to "User -> Organization -> Secret  Credentials", create a full access "Access Key", set down it as `<Password>`, and also "Organization ID" as `<OrgID>`.

### Receive Devices' Messages <a href="#receive-activations" id="receive-activations"></a>

Let’s listen for all of your devices' messages.

1. Open a terminal window and execute the following command.

{% code title="Shell" %}

```bash
mosquitto_sub \
    -h openstream.api.sensecap.seeed.cc \
    -t '/device_sensor_data/<OrgID>/+/+/+/+' \
    -u 'org-<OrgID>' \
    -P '<Password>' \
    -I 'org-<OrgID>-quickstart' \
    -v
```

{% endcode %}

You should replace `<OrgID>` and `<Password>` with the ones you set down from "Credentials".

2\. Power up devices, while devices keep sending messages, you should see outputs like:

{% code title="Shell" %}

```javascript
/device_sensor_data/xxxx/2CF7F12XXXXXXXXX/1/2CF7F13XXXXXXXXX/4105 {"value":0,"timestamp":1544151824139}
/device_sensor_data/xxxx/2CF7F12XXXXXXXXX/1/2CF7F13XXXXXXXXX/4097 {"value":23,"timestamp":1544151900992}
/device_sensor_data/xxxx/2CF7F12XXXXXXXXX/1/2CF7F13XXXXXXXXX/4101 {"value":101629,"timestamp":1544151901112}
/device_sensor_data/xxxx/2CF7F12XXXXXXXXX/1/2CF7F13XXXXXXXXX/4098 {"value":71,"timestamp":1544151900992}
/device_sensor_data/xxxx/2CF7F12XXXXXXXXX/1/2CF7F13XXXXXXXXX/4099 {"value":69.12,"timestamp":1544151902224}
/device_sensor_data/xxxx/2CF7F12XXXXXXXXX/1/2CF7F13XXXXXXXXX/4100 {"value":437,"timestamp":1544151922137}
```

{% endcode %}

It shows each data collected by sensors, with `Device EUI` , `Device Channel`,  `Sensor EUI`, `Measurement ID`, `Measurement Value`, and  `timestamp`, see the [reference](/doc/data-openstream-api/api-reference.md#message-topic) for more details.

#### Subscribe a Specific Field

You can also subscribe a specific field in the topic, so that you could get the data from a single device, or a single channel.

{% code title="Shell" %}

```bash
mosquitto_sub \
    -h openstream.api.sensecap.seeed.cc \
    -t '/device_sensor_data/<OrgID>/2CF7F12XXXXXXXXX/#' \
    -u 'org-<OrgID>' \
    -P '<Password>' \
    -I 'org-<OrgID>-quickstart' \
    -v
```

{% endcode %}

You should replace `<OrgId>` and `<Password>` with what you got from "Credentials", and replace `2CF7F12XXXXXXXXX` with the `Device EUI` you own.

🎉 Congratulations! Now you know how to monitor and receive messages via MQTT. Go build something awesome!