Versioning & deprecation · QashX Pay API

The public API uses URL versioning. Current stable major: v1.

Versioning scheme

Major in the URL path — e.g. /functions/v1/api-v1-payments. Breaking changes only.
Minor in the API-Version response header — e.g. API-Version: 2026-07-15. Additive fields, new endpoints, new event types.
Pin a minor by sending API-Version: YYYY-MM-DD on requests. If omitted, the account default is used.

What counts as breaking

Change	Requires major?
Removing an endpoint, field, or event	Yes
Renaming a field or enum value	Yes
Changing a field's type or nullability	Yes
Tightening validation on existing input	Yes
Adding an optional field	No
Adding a new endpoint or event	No
Adding a new enum value on output	No — clients must ignore unknowns

Deprecation policy

Announcement — logged in the changelog and emailed to every account owner.
Sunset headers — deprecated responses include Deprecation: true, Sunset: <RFC 3339 date>, and a Link: <url>; rel="successor-version".
Minimum 12-month window between announcement and removal for major versions; 6 months for minor deprecations.
Security exceptions — we may shorten the window with 30-day notice when required to close a vulnerability.

HTTP/1.1 200 OK
Deprecation: true
Sunset: Wed, 15 Jul 2027 00:00:00 GMT
Link: <https://asset-avenue-platform.lovable.app/docs/changelog.html#v2>; rel="successor-version"

Support matrix

Version	Status	Notes
`v1`	Stable	Current default. Long-term support.
`v0` (preview)	Retired	Not supported. Migrate to v1.