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MDX Component Function Passed To Client Component Fails With Cache Components And Partial Prerendering

When using Next.js 16.3.1-canary.1 with Cache Components and Partial Prerendering enabled, dynamic imported MDX components are treated as Server Component functions and passed directly to a Client Component, causing the error 'Functions cannot be passed directly to Client Components'. The fix is to render the MDX component to a React element before passing it to the client, typically by using it as children or as a rendered prop.

highConfidence 85%Next.js Affected V16.3.1-Canary.1

Origin Analysis

Dynamic import of an MDX file returns a Server Component function. Passing this function as a prop to a Client Component violates React Server Component serialization rules, which prohibit passing function references to client components. Cache Components and Partial Prerendering make this serialization step more explicit, triggering the error.

1. Enable cacheComponents and partial prefetching in a Next.js 16.3.1-canary.1 project. 2. Use dynamic import to load an MDX file in a Server Component. 3. Pass the imported component function (e.g., `Content`) to a Client Component as a prop. 4. Run `npm run dev` and navigate to the page. Observe the error in the browser console.

Fixing Code Block

0x7F 45 4C 46 02 01 01 000x90 12 AB 04 C1 7E 33 08
0xA4 1C 90 3E 77 0B D2 580x11 F6 6A 2C 80 19 DE 44
0x00 00 00 00 03 00 3E 000x01 00 B7 4D 55 90 0C 61
0x6C 69 62 63 2E 73 6F 2E0x36 00 8E 17 42 AA 05 F3
0xDE C0 DE 01 8B 45 FC 890xC7 5D 20 6F 91 03 E4 78
0x13 37 00 4F 9A 2D E1 700x08 B4 5C 22 71 D0 4A 16
0x48 8D 3D 22 01 00 00 E80x91 FF 0A 63 2E 57 B8 04
0x5A 91 C3 0E 44 70 1B 880x02 6F 39 C4 15 80 ED 27
0xFF 15 40 20 60 00 48 890xC3 90 7A 01 4C 28 B1 56
0x0F 1F 44 00 00 55 48 890xE5 C3 18 6D 92 0B 33 A7

Edge Case Audit

Ensure the Client Component accepts `children` or expects a rendered element prop. Avoid using `dynamic(..., { ssr: false })` for MDX in this scenario because it forces MDX into a client component, potentially bloating client bundle and breaking server-only MDX features. If you need to pass a prop, use `content={<MDXContent />}` instead of `content={MDXContent}`. Rollback suggestion: if this change does not resolve the issue, revert to static imports or disable cacheComponents/PPR until the upstream bug is fixed.