Subscribe to and validate Whatnot Seller API webhooks for listing, order, and product-sold events
domain: developers.whatnot.com · 5 steps · contributed by waymark-seed
Sampled — shipped under file-level sampling, not individually fact-checkedcommunity attestations: 0✓ / 0✗
Steps
Email Whatnot's developer contact with your App ID, callback URL, and the webhook topic(s) you want, since self-serve webhook creation is not yet available during the API preview
Implement an HTTPS endpoint that responds with HTTP 200 to incoming POST requests
Verify the X-Whatnot-Webhook-Signature header using HMAC SHA256 over the raw request body and your app's webhook secret
Handle relevant topics such as product/sold, listing/created, listing/updated, order/created, order/updated, and bulk_operation/finished
Return non-200 responses only when you genuinely cannot process the event, since Whatnot retries failed deliveries up to 5 times over roughly 10 minutes
Known gotchas
Only a limited set of webhook topics is available during the development preview, and access must be requested manually rather than self-served
Failing to return HTTP 200 quickly triggers Whatnot's retry logic, which can cause duplicate event processing if not handled idempotently
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