> For the complete documentation index, see [llms.txt](https://leandexer.gitbook.io/home/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://leandexer.gitbook.io/home/technical/notifications/webhook.md).

# Webhook

When setting up a project, you can choose between two channels of notifications:

* email
* webhook

On this page, we will focus on how to set up a webhook in your application to receive the data from Leandexer.

### What is a webhook?

A webhook is a method used to send real-time data from one application to another based on specific events. This is achieved by configuring a URL endpoint in the receiver application, which listens for incoming HTTP requests triggered by the sender application whenever the designated event occurs. Webhooks enable seamless, automated data transfers and integrations without the need for continuous polling or manual updates.

### Setting up your webhook

To set up the webhook, simply define a new route on your back-end router, using the following payload as request body:

```json
{
    "smart_contract_address": String,
    "project": {
        "id": BigInteger,
        "name": String
    },
    "time": BigInteger, // epoc time format
    "network": String,
    "event": {
        "name": String,
        "payload": {
          "encoded": String, // hex string encoded payload 
          "decoded": {
              "from": String,
              "to": String,
              "amount": BigInteger
          }
      },
      "block_number": BigInteger
    }
}
```

A little explanation of the code above:

* `smart_contract_address`: the address of the smart contract concerned by the notification
* `project` are the information related to the project sending the notification: the name and the identifier
  * `id` is the internal identifier of the project in the system, that you can use on your application to map data
  * `name` is the label you attached to your project when creating it in the Leandexer App
* `time` is the [epoch](https://en.wikipedia.org/wiki/Epoch_\(computing\)) formated time of the emitted event 
* `network` is the name of the network on which the event was emitted 
* `event` is all the data related to the event itself:
  * `name` the name of the event, as emitted by the smart contract (i.e. `Transfer` `Approval` ...)
  * `payload` is the payload of the event, containing:
    * `encoded` the hexadecimal encoded string, as read on the blockchain
    * `decoded` the decoded, humanly readable content of the event:
      * `from` the wallet which emitted the transaction
      * `to` if eligible, the wallet receiving the transaction
      * `amount` if eligible, the amount exchanged during the transaction
  * `block_number` the number of the block which validated the transaction