snapcasterDevelopers

    API reference · Webhooks

    Webhook test

    HOOK webhook.test

    Snapcaster sends this event when your integration calls POST /webhooks/test, and at no other time. It reports no change: use it to check that your receiver is reachable, verifies the signature and answers 2xx. event_id is the one the call returned. The envelope, signing and retries match order.created; see https://developers.snapcaster.ca/guide/webhook-signing. Every subscription, inventory, orders and both, can request it. Deduplicate by event_id.

    Example

    Delivery payload: Signed webhook test payload
    {
  "event_id": "evt_5b0e7c2d9a4f41e8b3c6d1a07f2e9b58",
  "type": "webhook.test",
  "created_at": "2026-09-04T19:00:00.000Z",
  "data": {
    "seller_id": 42,
    "platform_id": 7
  },
  "api_version": "2026-10"
}

    Signature headers

    Snapcaster sends a POST to your webhook endpoint with these headers. Webhook signing shows how to verify them.

    X-Snapcaster-Timestamp string required

    Unix seconds when the request was signed; reject if outside a ±5 minute window.

    X-Snapcaster-Signature string required

    sha256= + lowercase hex of HMAC_SHA256(signingSecret, timestamp ‖ raw request body).

    Delivery payload

    The signed webhook.test event.

    Payload type: WebhookTestEvent

    Envelope fields

    event_id string required

    A globally unique event id that stays the same across retries. Use it to deduplicate deliveries (STABLE).

    Example evt_5b0e7c2d9a4f41e8b3c6d1a07f2e9b58

    type string required

    The event type (STABLE).

    Constraints: allowed values: webhook.test Example webhook.test

    created_at string required

    ISO-8601 UTC instant of the change the event reports; unchanged across retries (STABLE).

    Example 2026-09-04T19:00:00.000Z

    data WebhookTestEventData required

    The operation or event payload.

    api_version string required

    The dated API version used for this payload, frozen when Snapcaster queued the delivery. Changing the platform pin does not change queued events or retries; they keep the same version. See https://developers.snapcaster.ca/guide/api-versioning (STABLE).

    Constraints: allowed values: 2026-10 Example 2026-10

    Payload fields

    data.seller_id integer required

    The seller whose API key asked for the test. Route the event by it as you route real ones (STABLE).

    Example 42

    data.platform_id integer required

    Your platform, which owns the webhook endpoint (STABLE).

    Example 7

    Receiver response

    200 - Return any 2xx after verifying the event and durably accepting it. This event moves no stock, so its 2xx acknowledges no sale and leaves every stock hold as it was.