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Invoice Alerting Example (with Zapier)

invoice alerting flow

In this example, we are going to build an alert anytime a new invoice is emitted. To create this workflow, we are using:

  1. Lago's webhook when a new invoice is emitted;
  2. Zapier as an automation tool, to catch, tranform and send the data; and
  3. Slack as the "receiver" to alert your team anytime a new invoice is created.

Zapier alerting flow

1. Catch a webhook when a new invoice is emitted

Lago automatically creates an invoice when a billable period is over. The invoice's payload gives you a detailed view of what has been invoiced. The first action we need to perform is to catch this invoice with a webhook:

  1. In Zapier, create a new Zap;
  2. Use the Webhooks by Zapier as the trigger of this Zap;
  3. Select the Catch Raw Hook event trigger;
  4. Copy the Zapier Webhook URL and paste it in Lago (Developers > Webhooks > Add a webhook); and
  5. Catch your first webhook when an invoice is emitted (whenever you assign an add-on or a subscription).

2. Run a script to transform the webhook

In Zapier, create a second action by clicking the + icon. This new event action is used to format the webhook with a breakdown of fields that can be used in a message.

  1. Select Code by Zapier as a new Event Action;
  2. Click on Javascript as the event code language to run;
  3. Create a field called payload. The value of this field is the full Raw body of your invoice object received);
  4. Run the script (code snippet below) in the Code section;
  5. Test the action. If valid, it returns a breakdown of fields.
var obj = JSON.parse(inputData.payload);

if(obj.object_type == "invoice"){
return obj

Script to tranform the invoice payload Breakdown of the invoice payload

3. Send a message to a Slack Channel

Once you catch the breakdown of fields returned by the invoice payload, you can easily use them to create a Slack text message.

In Zapier, create a third action by clicking the + icon. This new event action is used to send a message to Slack by using the fields of the invoice payload.

  1. Select Slack as a new app action;
  2. Select the Send Channel Message action;
  3. Choose the targeted Slack Account;
  4. Choose the targeted Slack Channel; and
  5. Create a message by using the fields returned by the payload.

By testing and validating the entire Zap, a Slack message is sent anytime a new invoice is emitted by Lago. You can use the same message example as detailed below:

Breakdown of the invoice payload Slack text message