Versioning
Dated versions, the AlphaCount-Version header, and what may change without one.
The API's versions are dates. Every answer names the version it was made with:
AlphaCount-Version: 2026-10-19Send the same header to pin a version. A version AlphaCount does not know is refused with 400 api_version_unknown,
which lists the supported ones in supported. Without the header, you get the current version.
What changes without a new version
- a new operation, a new optional request field, a new field in an answer;
- a new error code on an operation, a new value of a field documented as open;
- a new webhook event.
Write your client so that a field it does not know does not break it.
What needs a new version
Removing or renaming a field, changing its type or meaning, making an optional request field required, removing an operation. The previous version keeps working for at least 90 days after the new one is announced in the changelog.
A check compares every change to the published contract with the version before it and refuses a breaking one that does not come with a new version.
Webhooks
Webhook payloads have a version of their own, in the envelope's api_version (currently 2026-10-07). New
fields may appear; existing ones are not renamed or removed without a new api_version.