Changelog & versioning

The API is versioned by date. Your integration is pinned to a single date-stamped version. We won't change anything about that version's behaviour without you opting in.

How versioning works

The version pinned to your integration is visible at Settings → API version and on every response as the X-API-Version header. It's also embedded in every webhook event:

{
  "id": "evt_…",
  "object": "event",
  "type": "listing.published",
  "api_version": "2026-05-07",
  …
}

Newly-created integrations always pin to the latest dated version at creation time. To roll an existing integration forward (to opt into breaking changes from a newer version), email support@watchtraderhub.com. We don't auto-roll because we don't want to break your production integration on our schedule.

What counts as a breaking change

Breaking changes (mint a new dated version):

• Removing an endpoint, field, or event type.
• Renaming an endpoint, field, or event type.
• Tightening a validation rule (a payload that used to be accepted is now rejected).
• Changing the meaning of a field, e.g. a status enum value being repurposed.
• Changing the algorithm of webhook signing or any header format.
• Changing the cursor format or pagination semantics.

Non-breaking changes (ship continuously, pinned versions automatically benefit):

• Adding a new endpoint.
• Adding a new optional field to a request body.
• Adding a new field to a response body.
• Adding a new event type. Existing subscriptions still apply; the wildcard * picks it up.
• Adding a new error code (existing codes keep their meaning).
• Improving error message wording.

Versions