LemonSqueezy Integration

Connect your LemonSqueezy account to Windback via the custom webhook endpoint to detect subscription cancellations, failed payments, and successful recoveries.

LemonSqueezy does not have a native Windback integration. This guide uses a lightweight Node.js relay function that receives LemonSqueezy webhooks and forwards them to Windback’s custom webhook endpoint.

Webhook URL

Your Windback custom webhook URL is:

https://api.windbackai.com/api/v1/webhooks/custom/<your_public_key>

Your public key starts with pub_ and is found in Settings > API Keys.

Setup

Deploy the Relay Function

Deploy the Node.js relay function below to your server or a serverless platform (Vercel, AWS Lambda, etc.). This function receives LemonSqueezy webhooks, maps the payload, and forwards it to Windback.

Add the Webhook in LemonSqueezy

Go to LemonSqueezy Dashboard > Settings > Webhooks
Click Add Webhook (or the + button)
Paste the URL of your deployed relay function
Enter a signing secret and store it securely
Select the events listed below
Click Save

Store the signing secret in an environment variable. You will need it to verify incoming webhook signatures.

Select Webhook Events

Enable the following events in LemonSqueezy:

LemonSqueezy Event	Windback Event Type	Description
`subscription_cancelled`	`cancellation`	Customer canceled their subscription
`subscription_payment_failed`	`payment_failed`	Subscription payment attempt failed
`subscription_payment_success`	`payment_recovered`	Payment succeeded after a previous failure

Verify the Connection

Create a test subscription in LemonSqueezy’s test mode
Cancel the subscription to trigger a subscription_cancelled event
Check your Windback dashboard for the new churn event

Data Mapping

LemonSqueezy webhooks use a nested data.attributes format. The relay function maps these fields to Windback’s custom webhook format:

LemonSqueezy Field	Windback Field	Notes
`data.attributes.user_email`	`customer_email`	Subscriber email address
`data.attributes.user_name`	`customer_name`	Subscriber name
`data.attributes.product_name`	`plan_name`	LemonSqueezy product name
`data.attributes.variant_name`	`plan_name` (fallback)	Used if product name is not set
`data.attributes.first_subscription_payment.amount`	`mrr`	Amount in cents
`data.attributes.first_subscription_payment.currency`	`currency`	ISO 4217 code
`data.attributes.created_at`	`tenure_days`	Calculated from subscription start

Relay Function

const express = require("express");
const app = express();
app.use(express.json());

const WINDBACK_URL =
  "https://api.windbackai.com/api/v1/webhooks/custom/pub_your_key";

const EVENT_MAP = {
  subscription_cancelled: "cancellation",
  subscription_payment_failed: "payment_failed",
  subscription_payment_success: "payment_recovered",
};

app.post("/lemonsqueezy-webhook", async (req, res) => {
  const { meta, data } = req.body;
  const eventName = meta?.event_name;

  const windbackEventType = EVENT_MAP[eventName];
  if (!windbackEventType) {
    return res.status(200).json({ status: "skipped" });
  }

  const attrs = data?.attributes || {};

  const tenureDays = attrs.created_at
    ? Math.floor(
        (Date.now() - new Date(attrs.created_at).getTime()) / (1000 * 86400)
      )
    : undefined;

  // LemonSqueezy provides amount in the subscription payment object or
  // as a top-level attribute depending on the event type
  const payment = attrs.first_subscription_payment || {};

  const payload = {
    customer_email: attrs.user_email,
    customer_name: attrs.user_name || undefined,
    event_type: windbackEventType,
    mrr: payment.amount || attrs.subtotal || undefined,
    currency: (payment.currency || attrs.currency || "usd").toLowerCase(),
    provider: "lemonsqueezy",
    plan_name: attrs.product_name || attrs.variant_name || undefined,
    tenure_days: tenureDays,
  };

  try {
    await fetch(WINDBACK_URL, {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify(payload),
    });
  } catch (err) {
    console.error("Failed to forward to Windback:", err);
  }

  res.status(200).json({ status: "ok" });
});

app.listen(3000, () =>
  console.log("LemonSqueezy relay listening on port 3000")
);

export default async function handler(req, res) {
  if (req.method !== "POST") {
    return res.status(405).json({ error: "Method not allowed" });
  }

  const WINDBACK_URL =
    "https://api.windbackai.com/api/v1/webhooks/custom/pub_your_key";

  const EVENT_MAP = {
    subscription_cancelled: "cancellation",
    subscription_payment_failed: "payment_failed",
    subscription_payment_success: "payment_recovered",
  };

  const { meta, data } = req.body;
  const eventName = meta?.event_name;
  const windbackEventType = EVENT_MAP[eventName];

  if (!windbackEventType) {
    return res.status(200).json({ status: "skipped" });
  }

  const attrs = data?.attributes || {};
  const payment = attrs.first_subscription_payment || {};

  const tenureDays = attrs.created_at
    ? Math.floor(
        (Date.now() - new Date(attrs.created_at).getTime()) / (1000 * 86400)
      )
    : undefined;

  await fetch(WINDBACK_URL, {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({
      customer_email: attrs.user_email,
      customer_name: attrs.user_name || undefined,
      event_type: windbackEventType,
      mrr: payment.amount || attrs.subtotal || undefined,
      currency: (payment.currency || attrs.currency || "usd").toLowerCase(),
      provider: "lemonsqueezy",
      plan_name: attrs.product_name || attrs.variant_name || undefined,
      tenure_days: tenureDays,
    }),
  });

  res.status(200).json({ status: "ok" });
}

Replace pub_your_key with your actual Windback public key. Never commit your real key to version control.

Webhook Resilience

Windback’s custom webhook endpoint always returns HTTP 200 regardless of internal processing status. Your relay function should also always return 200 to LemonSqueezy to prevent webhook retries and eventual deactivation.

LemonSqueezy signs webhook payloads using an HMAC signature in the X-Signature header. We strongly recommend verifying this signature in your relay function before forwarding to Windback. See LemonSqueezy’s webhook docs for details.

Getting Started

Features

Integrations

Widget

LemonSqueezy

LemonSqueezy Integration

Webhook URL

Setup

Data Mapping

Relay Function

Webhook Resilience

​LemonSqueezy Integration

​Webhook URL

​Setup

​Data Mapping

​Relay Function

​Webhook Resilience

LemonSqueezy Integration

Webhook URL

Setup

Data Mapping

Relay Function

Webhook Resilience