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## Catalyst 1.12.0

Catalyst 1.12.0 serves the Universal Commerce Protocol (UCP) endpoints for agentic commerce on your storefront's own domain, and stops a per-request header from making every Next.js Data Cache lookup miss.

* **UCP endpoints are proxied to BigCommerce** — agents discover and call UCP on the storefront's public domain, but the protocol is served by the BigCommerce platform rather than by Catalyst. `/.well-known/ucp` and `/api/ucp/*` now proxy through to BigCommerce for every HTTP method, where previously `/api/ucp/*` returned a 404 and `/.well-known/ucp` was locale-redirected. Only the headers the [UCP REST transport spec](https://ucp.dev/2026-04-08/specification/checkout-rest/) defines are passed in either direction, and no new environment variable is required.
* **Customized proxies need one update** — if you have customized `proxy.ts`, add `withUcpProxy` as the first argument to `composeProxies` and add `/api/ucp/:path*` to `config.matcher`. An unmodified `proxy.ts` picks both up from the upgrade.
* **Data Cache lookups hit again** — `X-Correlation-ID` is no longer sent on cacheable GraphQL requests. Next.js builds its Data Cache key from the fetch URL, method, body, and headers, so a correlation ID regenerated on every request produced a unique key on every request. Fetches configured with `next: { revalidate }` could never hit: each one went out to the BigCommerce GraphQL API and wrote an entry that nothing would ever read. On a product page that is roughly 12 queries per page view. The header now follows the same rule as `X-Forwarded-For`, and is attached only to `no-store` and `no-cache` requests, which are uncacheable by construction.

See the full [1.12.0 release notes](/developer/docs/storefront/catalyst/release-notes/1-12-0) for migration details and release tags.