@clerk/nextjs 7.2.8 breaks with e.isFetched' is undefined

[CodingFabian]

After Upgrading 7.2.7 to 7.2.8 our website broke with:

TypeError: e.isFetched is not a function. (In 'e.isFetched()', 'e.isFetched' is undefined)

Claude investigated this:

Root cause: The @clerk/nextjs@7.2.7 → 7.2.8 bump brought in @clerk/shared@4.8.6, which changed its @tanstack/query-core dependency from the exact pin 5.90.16 to the range ^5.90.16. That resolved to 5.100.6, which added isFetched() as a new method on the Query class and has the QueryObserver call query.isFetched().

Why only production: Clerk's production JS SDK (loaded when __client_uat cookie is present) bundles its own @tanstack/query-core internally (an older version without isFetched()). When @clerk/shared@4.8.6's QueryObserver (from 5.100.6) tries to observe queries from that bundled QueryClient, it calls query.isFetched() on a Query object that doesn't have that method → undefined is not a function.

[keepforever]

I experienced the same issue when I bumped as follows:

@clerk/react-router               ^3.1.7  →    ^3.1.8

I also noticed that if I bump react-query deps to ^5.100.6, while keeping @clerk/react-router: ^3.1.7, I get the same error.

@tanstack/react-query           ^5.100.5  →  ^5.100.6
 @tanstack/react-query-devtools  ^5.100.5  →  ^5.100.6

[jacekradko]

@CodingFabian Thanks for filing the report. Can you check this again with https://github.com/clerk/javascript/releases/tag/%40clerk%2Fnextjs%407.2.9 ?

[CodingFabian]

still the same error on 7.2.9 maybe related to caching since you did seem to solve the underlying issue.

[vcheeze]

Can confirm the same error for me when upgrading @clerk/tanstack-react-start, although I'm trying to isolate whether this is related to my @tanstack/react-query version or not.

[ipranay]

Hit this on @clerk/nextjs@7.2.9 today. Filing a confirmation that 7.2.9 doesn't fully resolve it and our workaround in case it helps others.

Repro

• @clerk/nextjs@7.2.9 (latest stable as of writing)
• @tanstack/react-query@^5.100.6 resolved transitively via @clerk/shared@4.8.7's declared ^5.100.6 peer
• Crash on any component using useOrganization() / useUser() etc.:

TypeError: query.isFetched is not a function
  at QueryObserver.createResult (@tanstack/query-core/build/modern/queryObserver.js:331:24)
  ...
  at useBaseQuery (@clerk/shared/dist/runtime/react/index.mjs:334:55)
  at useClerkQuery (@clerk/shared/dist/runtime/react/index.mjs:372:9)
  at useOrganization (@clerk/shared/dist/runtime/react/index.mjs:1206:18)

What we found

Inspected the runtime Query instance from the active Clerk QueryClient in the browser console:

const q = window.Clerk.__internal_queryClient.client.getQueryCache().getAll()[0];
typeof q.isFetched          // → "undefined"
Object.getPrototypeOf(q).constructor.name  // → "k"  (minified Query class from clerk-js CDN bundle)

So even on @clerk/nextjs@7.2.9, the Query instances coming from the clerk-js CDN bundle still don't expose isFetched() as a method, while the consumer-side @clerk/shared@4.8.7 resolves @tanstack/query-core@5.100.7 whose QueryObserver.createResult calls query.isFetched() at line 327. Same cross-bundle mismatch as the original report — the CDN bundle either hasn't picked up #8432 in our region or is being served from a stale cache.

Bisected @tanstack/query-core: the change landed between 5.91.0 (computes inline: isFetched: newState.dataUpdateCount > 0 || newState.errorUpdateCount > 0) and 5.91.2 (calls query.isFetched()).

Workaround

Pinned @tanstack/query-core to 5.91.0 via yarn resolutions to force the consumer-side QueryObserver back to the inline computation, which works against any Query shape:

// package.json
{
  "dependencies": {
    "@tanstack/react-query": "5.91.0",
    "@tanstack/react-query-devtools": "5.91.0"
  },
  "resolutions": {
    "@tanstack/query-core": "5.91.0"
  }
}

This sidesteps the cross-bundle contract entirely — both old and new clerk-js Query shapes satisfy the 5.91.0 observer.

Looking forward to the structural fix mentioned in #8432 that moves QueryClient ownership into @clerk/shared.

[keepforever]

Yeah, I'm still getting the isFetched is not a function error when I bump to:

"@clerk/react-router": "^3.1.9",
"@tanstack/react-query": "^5.100.7",

[jacekradko]

We just shipped the latest clerk-js@6.8.0 which has the @tanstack/query-core bump.

[vcheeze]

Thanks @jacekradko. Issue is fixed now!