Ulinkly REST API versioning and deprecation

The production REST API is versioned in the URL. New integrations must use:

https://api.ulink.ly/v1

Every documented response includes ULink-API-Version: 1. A new major path such as /v2 is introduced only when a change cannot remain backwards compatible. Additive response fields, new optional request fields, and new endpoints may ship within /v1; clients must ignore response members they do not recognize.

Legacy unversioned routes

The previous https://api.ulink.ly base remains available for compatibility and currently resolves to v1 behavior. It is deprecated as of August 25, 2026 and returns:

Deprecation: @1787616000
Link: <https://docs.ulink.ly/rest-api/versioning>; rel="deprecation"; type="text/html"

Move by adding /v1 after the host; operation paths and request bodies do not change.

Sunset policy

There is no scheduled shutdown date for the unversioned compatibility routes. If Ulinkly decides to remove a deprecated API version, it will:

1. Publish the date here at least six months before removal.
2. Return a standards-compliant Sunset HTTP-date on every affected response.
3. Link the migration guide with rel="deprecation" and, when applicable, rel="sunset".
4. Keep the replacement version and its OpenAPI contract available throughout the notice period.

Agents should treat the live Deprecation, Sunset, and Link fields as the authoritative lifecycle signal.

OpenAPI

The Ulinkly OpenAPI 3.1 specification lists the versioned server first and the deprecated unversioned compatibility server second.