fix: use next/root-params instead of headers() in cache components docs#304
Merged
Conversation
The previous getLocale/getRegion examples used headers() which breaks inside "use cache" boundaries. Replace with next/root-params API (Next.js 16.2+) which is cache-safe and automatically becomes part of the cache key.
- rootParams doesn't need a config flag, it's handled by the compiler - getLocale just returns await locale() directly - getRegion returns undefined instead of empty string
bgub
approved these changes
May 19, 2026
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Problem
The cache components docs recommended using
headers()ingetLocale.ts/getRegion.ts. This breaks inside"use cache"boundaries because Next.js forbids dynamic APIs likeheaders()in cached scopes:Solution
Replace
headers()with thenext/root-paramsAPI (Next.js 16.2+). Root params can be read from anywhere in the component tree — including inside"use cache"boundaries — and the root param value automatically becomes part of the cache key.Requires:
experimental.rootParams: truein next.config.js[locale]to be a root parameter (noapp/layout.tsxabove it)Context
Follow-up to #303. Identified via testing — see thread in #moss-pager.