🪝 Webhook

Sentio allows you to define the json message you want to send to webhook. In every webhook call, Sentio sends an array of json messages along with a few more metadata fields.

• event_id: This is unique for the messages from a channel. If you receive an ID more than once, the new message should override the old message. This is required due to blockchain reorganization.
• timestamp_micros: The timestamp in microseconds when the event happened.
• version: The processor version. Every new upload of the processor bumps the version by 1.

The actual json data is in the field "data" (What you pass in from the processor). A sample data looks like:

[ ... array of following object
  {
    "export_name": "SwapEvent",
    "event_id": 1,
    "timestamp_micros": 1668099816652000,
    "version": 1,
    "data": { ... your exporting data }
  },
  {
    "export_name": "SwapEvent",
    "event_id": 2,
    "timestamp_micros": 1668099816653000,
    "version": 1,
    "data": { ... your exporting data }
  },
  ...
]

Your webhook endpoint should acknowledge a message by returning http status code 20x (currently the acknowledgement deadline is 5 seconds), otherwise Sentio will retry sending the message with an exponential back off policy.

If Sentio attempts to deliver the message but can't receive acknowledgement, the message will be considered a dead letter eventually. Dead letters won't be delivered anymore, but can be pulled manually. The retention duration of dead letters is 7 days.

Pulling dead letters

You can call pulling API to get the dead letters in your project.

HTTP Request

GET https://app.sentio.xyz/api/v1/webhook/deadletter/{owner}/{project}?limit={limit}

Response body

A sample response looks like:

{
  "messages": [
    {
      "id": "6312269039920155",
      "attributes": {
        "channel_name": "test_channel"
      },
      "data": "{ ... array of messages }"
    },
    {
      "id": "6312269039920729",
      "attributes": {
        "channel_name": "test_channel"
      },
      "data": "{ ... array of messages }"
    },
    ...
  ]
}

Use Exporter in processor

You can use Exporter to send webhooks. Note that you need to provide the channel name notification-channel in the exporter (configured on the UI).

const exporter = Exporter.register("SwapEvents", "WebhookChannel")

Note: The WebhookChannel should be replaced by the name you created in the UI

To send webhook, use:

exporter.emit(ctx, { evt })

For configuring the notification channel, please refer to notification-channel