Router Cache misses on every navigation when Link href includes search params (15.x)

[Elusive7733]

Link to the code that reproduces this issue

https://github.com/Elusive7733/nextjs-router-cache-search-params-bug

To Reproduce

1. Clone the repo: git clone https://github.com/Elusive7733/nextjs-router-cache-search-params-bug
2. pnpm install && pnpm build && pnpm start
3. Open http://localhost:3000/home?tab=overview
4. Open DevTools Network tab, filter by "Fetch/XHR"
5. Click "Listings" → observe RSC network request
6. Click "Home" → observe RSC request (should have been cached from prefetch)
7. Click "Listings" again → another RSC request (never cached)

The app has 3 fully static pages (no cookies(), headers(), or searchParams usage) linked with search params:

  <Link href="/home?tab=overview">Home</Link>
  <Link href="/listings?tab=board">Listings</Link>
  <Link href="/investors?tab=vetted">Investors</Link>

Key observation: The page you hard-reload on is always cached (seeded entry). Pages navigated to via client-side navigation are never cached, every click triggers a full RSC fetch.

Removing the search params from the href (e.g. href="/listings" instead of href="/listings?tab=board") makes caching work correctly.

Current vs. Expected behavior

Current: Every client-side navigation to a static page triggers a full RSC fetch when the <Link> href includes search params, even though:

• The page is fully static (prerendered)
• staleTimes.dynamic: 30 is configured
• The response includes x-nextjs-stale-time: 4294967294 (~136 years)
• The prefetch response returns prerendered: true

Expected: After the initial prefetch, subsequent navigations within the stale time window should be served from the Router Cache with zero network requests - the same behavior as links without search params, or links with prefetch={true}.

Root cause in prefetch-cache-utils.js:

1. createLazyPrefetchEntry creates an AUTO prefetch with cache key /listings (search params excluded for AUTO)
2. Prefetch response returns prerendered: true → entry's kind is upgraded to FULL, but the cache key stays /listings (not updated to /listings?tab=board)
3. On navigation, getExistingCacheEntry looks up /listings?tab=board (with params) → cache miss
4. Fallback finds /listings entry but marks it aliased: true → only loading boundary used → full RSC fetch

Workaround: <Link href="/listings?tab=board" prefetch={true}> - forces FULL prefetch from the start, which keys with search params immediately

Provide environment information

Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 25.2.0: Tue Nov 18 21:08:48 PST 2025; root:xnu-12377.61.12~1/RELEASE_ARM64_T8132
  Available memory (MB): 16384
  Available CPU cores: 10
Binaries:
  Node: 22.14.0
  npm: 10.9.2
  Yarn: 1.22.22
  pnpm: 10.24.0
Relevant Packages:
  next: 15.5.7 // An outdated version detected (latest is 16.1.6), upgrade is highly recommended!
  eslint-config-next: N/A
  react: 19.1.2
  react-dom: 19.1.2
  typescript: 5.9.3
Next.js Config:
  output: N/A
 ⚠ An outdated version detected (latest is 16.1.6), upgrade is highly recommended!
   Please try the latest canary version (`npm install next@canary`) to confirm the issue still exists before creating a new issue.
   Read more - https://nextjs.org/docs/messages/opening-an-issue

Which area(s) are affected? (Select all that apply)

Linking and Navigating

Which stage(s) are affected? (Select all that apply)

Vercel (Deployed), next start (local), next dev (local)

Additional context

• Affects 15.x stable only. Verified that 16.x canary (16.2.0-canary.45) has a rewritten segment-cache architecture with Fallback wildcard tokens that handles this correctly. A
  backport to 15.x would help the many teams still on stable.
• Not reproducible in dev mode (getExistingCacheEntry has a NODE_ENV !== 'development' guard on the aliased fallback path)
• staleTimes config has no effect — the cache misses at the key lookup level before stale time is ever checked
• Related but different: Prefetch on the same pathname with different query params is ignored #47550 (prefetch with different query params ignored), Router Cache entry doesn't work when query params contain %20 #72927 (URL encoding in cache keys)

---

Tested on 16.2.0-canary.45, the bug is fixed in canary due to the new segment-cache architecture with Fallback wildcard tokens. However, this affects all users on 15.x stable with no documented workaround.

Workaround for 15.x: Add prefetch={true} to <Link> components that include search params in the href.

Filing this for:

1. Awareness - this is a common pattern (tabs, filters via search params) with no documentation about the caching pitfall
2. Potential 15.x backport consideration
3. Searchability — so others hitting this find the workaround