✨ NextJS Add addNextJSError component

[BeltranBulbarellaDD]

Motivation

Discussed in this RFC specifically here

Changes

(AI written)

Adds addNextjsError(error, context?) and NextjsErrorBoundary to @datadog/browser-rum-nextjs — the integration points for reporting errors from Next.js error boundaries to Datadog RUM.

addNextjsError(error, context?)

• Tags every error with framework: 'nextjs' context
• Adds nextjs.digest context when the error carries a digest property (server component errors — the hash links client-side errors to server-side logs)
• Uses onRumStart deferred callback so calls before SDK init are buffered and replayed
• Reserved fields (framework, nextjs.digest) are always applied last in the context merge, so user-provided context cannot overwrite them

NextjsErrorBoundary

• React class component wrapping addNextjsError for Pages Router client-side error catching
• Accepts a fallback render prop (NextjsErrorBoundaryFallback) and an optional onError callback
• Automatically calls addNextjsError in componentDidCatch

Test app & E2E

• Renamed test app from nextjs-app-router → nextjs (now covers both App Router and Pages Router)
• Added Pages Router test pages: pages-router/ index, user, guides, error boundary test
• E2E scenarios cover: router navigation (app + pages), client error (app + pages), server error with digest (app router), global error (app router), NextjsErrorBoundary catch + reset (pages router)

Both APIs exported from @datadog/browser-rum-nextjs main entry.

Test instructions

(AI written)

# Unit tests
yarn test:unit --spec packages/rum-nextjs/src/domain/error/addNextjsError.spec.ts

# E2E tests
yarn test:e2e -g "nextjs"

Navigating into test/apps/nextjs you can do yarn dev or yarn start (for production) and use the developer extension to test the events.

Checklist

• Tested locally
• Tested on staging
• Added unit tests for this change.
• Added e2e/integration tests for this change.
• Updated documentation and/or relevant AGENTS.md file

[cit-pr-commenter-54b7da]

Bundles Sizes Evolution

📦 Bundle Name	Base Size	Local Size	𝚫	𝚫%	Status
Rum	174.53 KiB	174.54 KiB	+20 B	+0.01%	✅
Rum Profiler	6.16 KiB	6.16 KiB	0 B	0.00%	✅
Rum Recorder	27.46 KiB	27.46 KiB	0 B	0.00%	✅
Logs	56.84 KiB	56.84 KiB	0 B	0.00%	✅
Flagging	944 B	944 B	0 B	0.00%	✅
Rum Slim	130.21 KiB	130.23 KiB	+20 B	+0.02%	✅
Worker	23.63 KiB	23.63 KiB	0 B	0.00%	✅

🚀 CPU Performance

Action Name	Base CPU Time (ms)	Local CPU Time (ms)	𝚫%
addglobalcontext	N/A	0.0047	N/A
addaction	N/A	0.0158	N/A
adderror	N/A	0.0141	N/A
addtiming	N/A	0.003	N/A
startview	N/A	0.0139	N/A
startstopsessionreplayrecording	N/A	0.0007	N/A
logmessage	N/A	0.0165	N/A

🧠 Memory Performance

Action Name	Base Memory Consumption	Local Memory Consumption	𝚫
addglobalcontext	N/A	27.41 KiB	N/A
addaction	N/A	51.57 KiB	N/A
addtiming	N/A	26.13 KiB	N/A
adderror	N/A	55.37 KiB	N/A
startstopsessionreplayrecording	N/A	25.57 KiB	N/A
startview	N/A	448.19 KiB	N/A
logmessage	N/A	44.66 KiB	N/A

🔗 RealWorld

[datadog-prod-us1-3]

✅ Tests

🎉 All green!

❄️ No new flaky tests detected
🧪 All tests passed

🎯 Code Coverage (details)
• Patch Coverage: 92.00%
• Overall Coverage: 77.29% (+0.07%)

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: 586c754 | Docs | Datadog PR Page | Was this helpful? React with 👍/👎 or give us feedback!}

[BeltranBulbarellaDD]

@codex pls review

[chatgpt-codex-connector]

💡 Codex Review

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Reviewed commit: 673952b723

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[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: f7678cbe8b

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Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
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[iadjivon]

Suggested change

	For **Server Component** errors, Next.js sends a generic message to the client and attaches `error.digest` — a hash that links the client-side error to your server-side logs. For **Client Component** errors, `error.message` is the original message and `digest` is absent.
	For **Server Component** errors, Next.js sends a generic message to the client and attaches `error.digest` — a hash that links the client-side error to your server-side logs. For **Client Component** errors, `error.message` is the original message and `error.digest` is absent.

Is the digest listed here meant to be the error.digest listed earlier?

If yes, I recommend writing it out fully to avoid any confusion.

If no, feel free to dismiss this comment. But I'd recommend clarifying where this digest originates/is used, since we are saying it is absent in this circumstance.

Let me know if you have any questions!

[iadjivon]

Hi there,
Thanks for sharing this PR with the Doc team!
I've approved this with a small comment.
Let us know if you have any questions!