feat(nextjs): Add support for Next.js 16 cache components #7595

jacekradko · 2026-01-14T02:42:08Z

Summary

Adds baseline support for Next.js 16 cache components (cacheComponents) by improving error detection and providing helpful error messages.

Add isNextjsUseCacheError() helper to detect "use cache" context errors
Update isPrerenderingBailout() to detect cache component prerendering errors
Update buildRequestLike() to provide helpful error message when auth() is called inside a "use cache" function
Update clerkClient() to re-throw "use cache" errors
Add unit tests for error detection helpers

Problem

When Next.js 16 cache components are enabled and a developer calls auth() or currentUser() inside a "use cache" function, they receive a cryptic error about headers() rejecting during prerendering.

Solution

Detect these errors and provide a helpful message with a code example showing the correct pattern:

Clerk: auth() and currentUser() cannot be called inside a "use cache" function.
These functions access `headers()` internally, which is a dynamic API not allowed in cached contexts.

To fix this, call auth() outside the cached function and pass the userId as an argument:

  async function getCachedUser(userId: string) {
    "use cache";
    const client = await clerkClient();
    return client.users.getUser(userId);
  }

  // In your component/page:
  const { userId } = await auth();
  if (userId) {
    const user = await getCachedUser(userId);
  }

Test plan

Unit tests added for isPrerenderingBailout() and isNextjsUseCacheError()
All 26 tests pass
Build succeeds
Manual testing with Next.js 16 test app (follow-up)

Summary by CodeRabbit

New Features
- Added support for Next.js 16 cache components, enabling enhanced compatibility with modern Next.js caching features and APIs.
Bug Fixes
- Enhanced error detection when authentication methods are used inside "use cache" functions.
- Improved error messages to clearly guide users on how to resolve conflicts between authentication calls and cached contexts.

_{✏️ Tip: You can customize this high-level summary in your review settings.}

- Add `isNextjsUseCacheError()` helper to detect "use cache" context errors - Update `isPrerenderingBailout()` to detect cache component prerendering errors - Update `buildRequestLike()` to provide helpful error message with code example when auth() is called inside a "use cache" function - Update `clerkClient()` to re-throw "use cache" errors - Add unit tests for error detection helpers

changeset-bot · 2026-01-14T02:42:13Z

🦋 Changeset detected

Latest commit: f5da1c6

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@clerk/nextjs	Patch

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vercel · 2026-01-14T02:42:14Z

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Project	Deployment	Review	Updated (UTC)
clerk-js-sandbox	Ready	Preview, Comment	Jan 14, 2026 2:42am

coderabbitai · 2026-01-14T02:44:23Z

📝 Walkthrough

Walkthrough

The changes add support for Next.js 16 cache components to the Clerk Next.js library. A new utility function isNextjsUseCacheError is introduced to detect when dynamic APIs are called within "use cache" blocks. The implementation includes regex patterns for error message detection, comprehensive tests covering various error scenarios, and integration into error handling paths in both the server utilities and clerk client. When such errors are detected, Clerk provides detailed, actionable error messages guiding users to move auth-related calls outside cached contexts.

🚥 Pre-merge checks | ✅ 2 | ❌ 1

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✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the main feature addition: support for Next.js 16 cache components, which is the primary objective of this PR.

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.changeset/nextjs-cache-components-support.md
packages/nextjs/src/app-router/server/__tests__/utils.test.ts
packages/nextjs/src/app-router/server/utils.ts
packages/nextjs/src/server/clerkClient.ts

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packages/nextjs/src/app-router/server/utils.ts

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packages/nextjs/src/app-router/server/utils.ts

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packages/nextjs/src/server/clerkClient.ts
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packages/nextjs/src/app-router/server/utils.ts

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packages/nextjs/src/server/clerkClient.ts
packages/nextjs/src/app-router/server/__tests__/utils.test.ts
packages/nextjs/src/app-router/server/utils.ts

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packages/nextjs/src/app-router/server/utils.ts

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packages/nextjs/src/server/clerkClient.ts
packages/nextjs/src/app-router/server/__tests__/utils.test.ts
packages/nextjs/src/app-router/server/utils.ts

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packages/nextjs/src/app-router/server/utils.ts

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packages/nextjs/src/server/clerkClient.ts (1)

packages/nextjs/src/app-router/server/utils.ts (1)

isNextjsUseCacheError (35-49)

packages/nextjs/src/app-router/server/__tests__/utils.test.ts (1)

packages/nextjs/src/app-router/server/utils.ts (2)

isPrerenderingBailout (7-28)

isNextjsUseCacheError (35-49)

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🔇 Additional comments (5)

packages/nextjs/src/app-router/server/utils.ts (2)

3-49: LGTM!

The new error detection helpers are well-implemented with proper type guards, case-insensitive regex patterns, and clear JSDoc documentation. The detection logic correctly handles both "use cache" and "cache scope" error variants.

65-84: LGTM!

The error handling flow is correctly ordered (prerendering bailout first, then use cache errors) and provides a clear, actionable error message with a concrete code example for developers.

packages/nextjs/src/app-router/server/__tests__/utils.test.ts (1)

1-92: LGTM!

Comprehensive test coverage for both helper functions, including edge cases for non-Error values and actual Next.js error message patterns. The tests validate both positive detection and negative cases (unrelated errors).

packages/nextjs/src/server/clerkClient.ts (1)

20-28: LGTM!

The error re-throwing logic correctly propagates the helpful error message generated by buildRequestLike and follows the same pattern as the prerendering bailout handling.

.changeset/nextjs-cache-components-support.md (1)

1-5: LGTM!

Changeset correctly documents the feature addition with an appropriate patch version bump.

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pkg-pr-new · 2026-01-14T02:45:21Z

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commit: f5da1c6

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feat(nextjs): Add support for Next.js 16 cache components #7595

feat(nextjs): Add support for Next.js 16 cache components #7595

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