Table of contents

Version history


v1 is the current version of the API.

You can access v1 of the API using these base URLs:

  • https://{register}
  • https://{register}


next is a preview of the upcoming API before that API becomes stable. You should not use it in production, since the API may change without notice.

The release schedule is:

  1. The GOV.UK Registers team releases the next API. You can use the next version of the API to test against backwards-incompatible changes before next becomes the stable API.
  2. When the next API is stable, it will be renamed to the next version (eg v2).
  3. After a set amount of time, the previous version of the API is deprecated.

You can access the next version of the API using this base URL:

  • https://{register}


Data model changes

The term “blob” replaces the term “item” (RFC-14).

Registers no longer have “indexes” (RFC-20).

These changes mean that:

  • you now access the resource at /blobs/{blob-hash} instead of /items/{item-hash}
  • the field item-hash has been replaced by blob-hash
  • blob-hash is computed differently from the existing item-hash vaues, so if your code relies on updates, you should fetch all the data again after updating to this version of the API
  • the field index-entry-number no longer exists (use entry-number instead)
  • /entries/{entry-number} now returns a single object instead of an array of objects
  • /records/{key} now returns a flat record object with the entry key using the reserved field _id, instead of an object indexed by the entry key. In addition the entry-number and entry-timestamp have been removed from the object. If you require these you can get them using the /records/{key}/entries endpoint.
  • /records now returns an array of record objects, instead of an object indexed by entry key