1. Dryad API - MQTT Sensor Data Integration

2. Webhook Integration (Preview - coming soon)

Dryad External MQTT Broker

The Dryad External Message Queuing Telemetry Transport (MQTT) broker facilitates the integration of its sensor data with third-party systems. This includes customers and partners who wish to integrate the Dryad cloud platform with their own IT systems, such as command and control systems, and other data analytics platforms. For instance, this integration can be utilized for weather data analysis.

The MQTT is based on publish/subscribe architecture. It consists of an MQTT broker and MQTT clients. The term client refers to both publishers (sensors) and subscribers (third-party systems) for messages.

Dryad sensors, such as wildfire sensors, publish sensor readings to the Dryad external MQTT broker. The MQTT broker keeps track of subscribers who have subscribed to different topics. When the broker receives a message on a specific topic, it distributes the message to all subscribers who subscribe to it.

For example, a wildfire sensor might publish its sensor readings to the topic /sensor/envmon/site1/sensor1. If a subscriber (client) has subscribed to the same topic, it will receive the same message. The message contains a payload (the actual sensor data) and metadata.

Connect

The connection is initiated when the client sends a CONNECT message to the Dryad external MQTT broker. The broker responds with a CONNACK message. Once the connection is established, the broker maintains it until either the client initiates a disconnect command or the connection is interrupted.

The CONNACK message contains a return code indicating whether the connection is successful or not. Please refer to the official MQTT documentation’s Connect Reason Code section to find out the possible return (reason) codes.

Subscribe

To receive messages on topics of interest as a client, you must first send a SUBSCRIBE message to the Dryad external MQTT broker. The SUBSCRIBE message can have a packet identifier and a list of subscriptions. Each subscription contains a topic and a QoS level.

To confirm each subscription, the Dryad MQTT broker sends a SUBACK acknowledgement message to you.

The SUBACK message contains the packet identifier of the original SUBSCRIBE message and a return code. The return code indicates whether the subscription has been granted or rejected. Please refer to the official MQTT documentation's SUBACK payload section to find out the possible return (reason) codes.

After receiving the SUBACK message, you will start receiving messages that match the topics you subscribed to when they were published.

Unsubscribe

If you no longer want to receive messages on a topic, you can send a UNSUBSCRIBE message to the Dryad external MQTT broker. With the UNSUBSCRIBE message, you must include a list of topics you want to unsubscribe from. To confirm the unsubscribe, the Dryad external MQTT broker sends a UNSUBACK acknowledgement message to you.

MQTT Client Configuration

To subscribe to topics and receive messages, you'll need an MQTT client to connect with the Dryad external MQTT broker. You can configure your MQTT client to communicate with the Dryad external MQTT broker based on one of the following options:

Credentials

The site serial ID, username, and password will be provided separately via email with the username and password shared via a 1Password link. The 1Password link is valid for a period of 7 days.

Secure Port

If your client supports Secure Socket Layer (SSL) connection mode, use that mode to communicate with the Dryad eternal MQTT broker whenever possible. The secure port uses SSL certificates generated by Let’s Encrypt. The ISRG Root X1 Certificate Authority (CA) certificate is available here and can be used for a secure connection. You can specify the file location of the isrgrootx1.pem when you connect to the broker with the secure port, 31393.

QoS

Dryad uses the default Quality of Service (QoS) level, which is QoS level 0 (delivery at most once) when publishing messages. So the maximum level of QoS the subscriber can expect is also 0. Read the Eclipse Mosquitto MQTT man page for more information.

Dryad MQTT Topics

This section describes all the Dryad external MQTT topics that you can subscribe to, either insecurely or securely, along with examples:

Receive All Sensor Data from a Site

Use the topic Receive All Sensor Data from a Site to receive messages from all sensors deployed on a site. You will receive one sensor data reading at a time on the same MQTT topic.

/sensor/envmon/<site serial id>/#

For example, to receive all sensor data from the site xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx, the topic is as follows:

/sensor/envmon/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx/#

The JSON payload of the message you will receive looks something like this (Please note that every time the payload you receive contains data from a single wildfire sensor):

{
    "siteId": "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
    "applicationNSId": "xxxxxxxx-xxxx-xxxx-xxxx-x",
    "sensorNSId": "sn-silvav2nxxx-xxxxxxxx-xxxx-xxxx-xx",
    "time": "2024-03-07T16:54:34.106672Z",
    "fireAlertStatus": 0,
    "temperature": 25.7,
    "humidity": 30,
    "airPressure": 67101.0,
    "latitude": 38.1714972222,
    "longitude": 23.7332222222,
    "batteryPct":98,
    "airQuality":659.0
  }

The table below explains each field in the JSON payload.

MQTT Clients

Dryad supports many commonly used MQTT clients. Currently, instructions for using the following MQTT clients are provided:

• Eclipse Mosquitto

• MQTTx

More to be added.

Eclipse Mosquitto

Eclipse Mosquitto's mosquitto_sub is part of the Mosquitto MQTT broker. With mosquitto_sub, you can subscribe to topics and also unsubscribe from topics.

Subscribe

With mosquitto_sub, the command syntax for subscribing to a topic is as follows:

mosquitto_sub -h <hostname> -p <port> -u <username> -P <password> [-–cafile <path_to_ca_cert.pem>] -t <message-topic> where,

• -h <hostname>: Specifies the MQTT broker's hostname.

• -p <port>: Specifies the MQTT broker's port number.

• -u <username>: Specifies the username for authentication.

• -P <password>: Specifies the password for authentication.

• --cafile <path_to_ca_cert.pem>: [optional, only use with SSL] Specifies the path to the CA certificate file in PEM format.

• -t <message-topic>: Specifies the MQTT topic you want to subscribe to.

For example, to subscribe to the topic /sensor/envmon/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx/#, the mosquitto_sub command is as follows:

Non-secure:

mosquitto_sub -h ext.mqtt.dryad.app -p 31383-u username-P password-t /sensor/envmon/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx/#

Secure (uses ISRG Root X1 CA certificate):

mosquitto_sub -h ext.mqtt.dryad.app -p 31393 -u username -P password --cafile isrgrootx1.pem -t /sensor/envmon/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx/#

You can find more about the command line options in the mosquitto_sub manual.

Unsubscribe

With mosquitto_sub, the command syntax for unsubscribing from a topic is as follows:

mosquitto_sub -h <hostname> -p <port> -u <username> -P <password> [-–cafile <path_to_ca_cert.pem>]-U <unsub-topic>

where,

• -h <hostname>: Specifies the MQTT broker's hostname.

• -p <port>: Specifies the MQTT broker's port number.

• -u <username>: Specifies the username for authentication.

• -P <password>: Specifies the password for authentication.

• --cafile <path_to_ca_cert.pem>: [optional, only use with SSL] Specifies the path to the CA certificate file in PEM format.

• -U <unsub-topic>: Specifies the MQTT topic you want to unsubscribe from.

For example, to unsubscribe from the topic /sensor/envmon/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx/#, the mosquitto_sub command is as follows:

Non-secure:

mosquitto_sub -h ext.mqtt.dryad.app -p 31383 -u username -P password -U /sensor/envmon/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx/#

Secure (uses ISRG Root X1 CA certificate):

mosquitto_sub -h ext.mqtt.dryad.app -p 31393 -u username -P password --cafile isrgrootx1.pem -U /sensor/envmon/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx/#

You can find more about the command line options in the mosquitto_sub manual.

MQTTx

This guide explains how to use MQTTx as an MQTT client to subscribe to sensor data from Dryad's external MQTT broker. MQTTx provides you a GUI for configuring and connecting to any MQTT broker, allowing you to create subscriptions to receive data.

• Download the MQTTx client and install it on your computer. It is available for Windows, Mac, and Linux, and you can also run it inside a Docker container.

• Start MQTTx.

• Click on the + New Connection button.

• Enter the following information in the New window. Here, we focus only on the basic and minimal parameters needed to create a subscription and connect to Dryad's external MQTT broker. Using other advanced parameters is beyond the scope of this example. You may refer to the MQTTx documentation for more information.

• You can connect to the Dryad's external MQTT broker in two ways:

  • Non-secure

  • Secure

• To connect in a non-secure way, enter/configure the following parameters under the General section:

  • Name: Enter any name to identify your subscription.

  • Host: mqtt:// + ext.mqtt.dryad.app

  • Port: 31383

  • Client ID: Auto generated.

  • Username: Username for your site, provided through 1Password

  • Password: Password for your site, provided through 1Password

  • SSL/TLS: Off

• To connect in a secure way, enter/configure the following parameters under the General section:

  • Name: Enter any name to identify your subscription.

  • Host: mqtts:// + ext.mqtt.dryad.app

  • Port: 31393

  • Client ID: Auto generated.

  • Username: Username for your site, provided through 1Password

  • Password: Password for your site, provided through 1Password

  • SSL/TLS: On

  • SSL Secure: On

• After configuring the required parameters, click on the Connect button.

• Once connected, you will see the following window. Click on the + New Subscription button.

• The New Subscription window appears. In the New Subscription window, enter the topic to subscribe to. The format of the topic is as follows.

  • /sensor/envmon/<site_id>/#

• Click on the Confirm button.

• The sensor data from your site will now be displayed in MQTTx as it arrives at the Dryad cloud/application. Make sure to select JSON from the dropdown menu to view the sensor data in a properly formatted way.

• The image below shows the sensor data under a non-secure connection (Port: 31383).

• The image below shows the sensor data under a secure connection (Port: 31393).

For more information, read MQTTx docs.

Dryad allows customers to receive sensor data via webhooks using the new Silvanet API integration feature in the Silvanet Site Management Application.

What is a Webhook

Webhooks send messages on specific events in formats like JSON, XML, or form-encoded data to specific HTTP(S) endpoints configured in your application. Silvanet uses JSON as the content type for its webhook messages.

How Webhooks Work

A webhook is a service that listens for specific events and sends a message to a designated URL (the endpoint) on your application when those events occur. For example, Dryad can send a webhook every time a fire alert event occurs, which will then be displayed in your application within the Silvanet Site Management Application.

The webhook consists of the following entities:

• Messages - These are the webhooks being sent. A message can have contents and a few other properties.

• Application - This is where the messages are sent to. You can create one application per organization on your platform.

• Endpoints - Endpoints are the URLs messages will be sent to. Each application can have multiple endpoints, and each message sent to that application will be delivered to all of them, unless you are not subscribed to specific events for each endpoint. Endpoints listen for webhook messages.

• Event - When an event occurs, it triggers a webhook message.

The following diagram shows how webhooks are sent to your endpoint if a specific event occurs.

Advantages of Using Webhooks

• Customers can add any number of endpoints to their application (Webhook Portal) and edit them.

• Customers can choose which event types are sent to which endpoint. By default, all messages are sent to all endpoints.

• Webhooks use stateless HTTP requests to ensure that no persistent connections are required.

• Webhooks follow an event-driven model, where a message is triggered only when specific events occur, reducing unnecessary communication.

• Webhooks allow replaying past and failed messages.

Webhook Configuration

The Silvanet API integration feature in the Silvanet Site Management Application allows you to configure webhooks by creating an application for each organization you have and then adding endpoints to each application. With these endpoints, you can subscribe to the event types you want, view messages, and recover/replay past and failed messages.

Creating an Integration Application

• Log in to the Silvanet Site Management Application using your credentials.

• On the sidebar, click API Integration.

• The Silvanet API Integration dashboard appears.

• Click on the Create Application button to create a new integration application.

• In the Create a New Integration Application dialog box, select the organization for which you want to create the application. For example, Dryad Internal.

• Click on the Submit button to create the application.

• The application you created will be listed under Current API Integrations.

Adding an Endpoint

To receive messages, you need to add an endpoint to the Application. Of course, you can add more than one endpoint.

• On the Silvanet API Integration page, under Current API Integrations, click on the application name you want to configure.

• The application page appears, and the application name can be seen at the top left of the page.

• Click Endpoints tab if it is not selected by default.

• Click on the Add Endpoint button.

On the New Endpoint page, configure the following:

• Endpoint URL -Enter your endpoint URL here. If you don't have an endpoint, you can click on the option "Configure an endpoint or test with Svix Play." This will automatically generate an endpoint and fill the textbox for you. You can also use a service like webhook.site to generate a URL for your HTTP endpoint.

• Description - Enter an optional description here mentioning what the endpoint is used for.

• Subscribe to events - Select one or more event types that you want to subscribe to by clicking on the checkboxes. If you want to add all the event types of a specific group, just click on the group.

• (Optional) Advanced Configuration - click to expand this section.

  • Select Endpoint rate limiting (throttling) checkbox.

  • Rate Limit (per second) - provide the maximum number of webhook messages allowed to send to this endpoint per second. For example, enter 10, if you want to limit it to 10 messages per second. 0 means unlimited.

• Click on the Create button.

• The endpoint is added to your application. Your page should look something similar to the following:

Viewing Messages

With the Endpoints tab selected, scroll down the page until you can see the table view. It shows all the received messages with their EVENT TYPE, MESSAGE ID, and TIMESTAMP.

• From the table, click a message to view its content. You will be switched to the Logs tab. The message content is simply a JSON object.

Message Attempts

There are two types of message attempts, labelled as:

Replay Messages

Use the following options to replay messages to recover past and failed messages:

• This option is suitable to replay all the messages from some point in the past.

• The following dialog box will appear with three options:

  • Resend this message - select this option to replay the message you selected from the table.

  • Resend all failed messages since - this will replay all the failed messages since the event time of this message.

  • Replay all missing messages since - this will replay all the messages that never attempted for this endpoint since the event type of this message.

Filtering Event Types / Messages

There are several ways you can filter messages.

• Filter event types or messages by message attempts using the following buttons:

  • All

  • Succeeded

  • Failed

• Using the Filters: Click on the Filters menu to expand it.

  • Event Types: Filter messages by event types by clicking on Filters > Event Type and searching for or selecting the event type(s).

  • Tags: Filter messages by tags.

  • After Date / Before Date: If you know approximately when the message was sent, you can further narrow down the list using the date filter.

Event Catalog

The Event Catalog can be treated as the built-in svix documentation for webhook integration, which provides up-to-date information about event types, their schemas, and examples.

Click Event Catalog tab. It lists and describes all the event types we expose.

Event Types

Click on an event type to expand its content. You can see its schema and example JSON payload.

Currently Dryad exposes three event types:

alert-event.new

A new relevant gas scan has been received in the context of an active alert.

Schema:

Example:

{
  "alert": "https://dryad.app/alert-center/63a6a704-5a7a-4d43-9716-10de0d7cc182",
  "confidence_level": 0.89,
  "datetime": "2024-04-30T18:10:00.000Z",
  "device": {
    "coordinates": {
      "coordinates": [
        13.404954,
        52.520008
      ],
      "type": "Point"
    },
    "eui": "CC1BAA0010000025",
    "name": "SN 12571"
  },
  "severity": "alert",
  "urn": "urn:forestfloor:alert-event:84382a41-f97f-441a-bb13-e141b2c4779b"
}

alert.new

A new fire alert has been triggered.

Schema:

Example:

{
  "datetime": "2024-04-30T18:10:00.000Z",
  "site": {
    "name": "If Berlin was a Forest",
    "url": "https://dryad.app/sites/999",
    "urn": "urn:forestfloor:site:baee084d-f6cf-45b0-8227-ac7bdad6ed49"
  },
  "url": "https://dryad.app/alert-center/63a6a704-5a7a-4d43-9716-10de0d7cc182",
  "urn": "urn:forestfloor:alert:63a6a704-5a7a-4d43-9716-10de0d7cc182"
}

wf.measurement.new

Wildfire sensor environmental measurement received.

Schema:

Example:

{
  "air_pressure": 102331,
  "air_quality": 145,
  "datetime": "2024-04-30T18:10:00.000Z",
  "device": {
    "coordinates": {
      "coordinates": [
        13.404954,
        52.520008
      ],
      "type": "Point"
    },
    "eui": "CC1BAA0010000025",
    "name": "SN 12571"
  },
  "energy_level": 0.67,
  "humidity": 57,
  "site": {
    "name": "If Berlin was a Forest",
    "url": "https://dryad.app/sites/999",
    "urn": "urn:forestfloor:site:baee084d-f6cf-45b0-8227-ac7bdad6ed49"
  },
  "temperature": 18.4
}

Editing an Endpoint

Follow the steps below if you want to update the endpoint URL.

• Navigate to your application and select the Endpoints tab if it is not selected by default. Then select the Endpoint you want to edit under the Endpoints. This will expand the Endpoint configuration section.

• Click on the Edit button next to the existing endpoint URL.

• Replace the existing endpoint URL with the new endpoint URL.

• Click on the Save button.

Editing Subscribed Events

With your application, you can edit your subscribed events on each endpoint at any time.

• Navigate to your application and select the Endpoints tab if it is not selected by default. Then select the Endpoint you want to edit the subscribed events. This will expand the Endpoint configuration section.

• In the right-side panel, under the Subscribed Events section, you can see which events you are subscribed to for this endpoint.

• Click the Edit button.

• Select or deselect the event types you want to subscribe to or unsubscribe from.

• Click the Save button.

Testing Endpoints

This feature allows you to test your endpoint to see if it will receive messages.

Navigate to your application and select the Endpoints tab if it is not selected by default. Then select the Endpoint you want to test. This will expand the Endpoint configuration section.

• Go to the Testing tab.

• Select an event type from the dropdown you want to test.

• Once you select an event type, its schema will display on the page along with an example JSON payload so you can see what fields will be sent with the message.

• Click Send Example button to send the message.

After sending a message for an event, if successful, you will be able to see it on the Overview tab.

Disabling an Endpoint

Navigate to your application and select the Endpoints tab, if it is not selected by default. Then select the Endpoint you want to disable. This will expand the Endpoint configuration section.

Disabling an endpoint will stop messages from being sent to that endpoint.

• Once disabled, a label named Disabled will appear on the endpoint page, as shown below.

To enable the endpoint again, click Enable Endpoint from the same menu.

Deleting an Endpoint

Navigate to your application and select the Endpoints tab, if it is not selected by default. Then select the Endpoint you want to delete. This will expand the Endpoint configuration section.