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updatedAt: 2026-09-09T17:07:01.000Z
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Fetch the complete documentation index at: https://developer.usebutton.com/llms.txt. Use this file to discover all available pages before exploring further. Append .md to any documentation page URL to get its markdown version.

# Changelog and Versioning

## Versioning

The API uses URI versioning. Every endpoint lives under a version prefix,
currently `/v1`.

* **Additive changes** do not change the version. New optional fields and new
  endpoints can appear under `/v1`, so build your integration to ignore
  fields it does not recognize.
* **Breaking changes** ship under a new major version, such as `/v2`. The
  previous version stays supported through a published deprecation window.

## Deprecation policy

When a version is scheduled for retirement, Button will:

* Announce it in this changelog with a retirement date.
* Support the retiring version for a minimum of 6 months from the
  announcement.
* Keep the previous major version available throughout that window so you
  have time to migrate.

## Changelog

Entries are dated, newest first.

| Date       | Change                                                                                                                                                         |
| ---------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| 2026-09-08 | `v1` general availability. Product lookup by URL, by retailer and product ID, and by GTIN. Category browsing. Batch lookup up to 50 items. Retailers endpoint. |