# How do I send revenue from my own checkout or any payment provider to my analytics?

Call DataFast's revenue API from your server after a payment succeeds: POST /api/revenue with a revenue API key as a Bearer token, plus site_id, amount, currency, the visitor_id captured at checkout and your order ID as event_id. Retries with the same event_id are not counted twice, and the payment appears under its original source.

## Steps

1. **Create a revenue API key.** In the site's settings. It is shown once; keep it server-side.
2. **Capture the visitor ID.** window.datafast?.visitorId in the browser, sent to your server with the checkout request.
3. **Call the API after payment.** curl -X POST https://datafast.app/api/revenue -H "Authorization: Bearer KEY" -H "Content-Type: application/json" -d '{"site_id":"SITE_ID","amount":49.00,"currency":"USD","visitor_id":"VISITOR_ID","event_id":"ORDER_ID"}'

## Limits

- The key is a write key: never ship it to the browser.
- amount must be greater than 0.

## FAQ

**What stops duplicates?**
Send your order ID as event_id (or the Idempotency-Key header); the same ID is recorded once.

**Can the MCP token call this?**
No. The MCP token is read-only and refused here.

Canonical page: https://datafast.app/solutions/add-revenue-tracking-to-any-checkout