feat(react-router): Add Experimental React Server Components (RSC) instrumentation by onurtemizkan · Pull Request #18882 · getsentry/sentry-javascript

onurtemizkan · 2026-01-19T12:32:50Z

Resolves: #17337

Adds experimental error capture and performance monitoring for React Router v7's React Server Components mode (v7.9.0+).

In RSC mode, entry.server.tsx is bypassed for server component renders, so wrapSentryHandleRequest never runs. HTTP spans are not parameterized, transaction names are not set, and errors in server components and server functions are not captured.

Server Components

Added wrapServerComponent() for error capture and span parameterization:

// app/routes/users.$id.tsx
import * as Sentry from '@sentry/react-router';

async function _UserPage({ params }: Route.ComponentProps) {
  const user = await getUser(params.id);
  return <UserProfile user={user} />;
}

export default Sentry.wrapServerComponent(_UserPage, {
  componentRoute: '/users/:id',
  componentType: 'Page',
});

Runs within the existing HTTP request span (does not create its own)
Sets transaction name on the isolation scope and parameterizes the root span (e.g., GET /users/:id)
Captures errors with mechanism type react_router.rsc
Redirect (3xx) and not-found responses are not captured as errors

Server Functions

Added wrapServerFunction() for "use server" functions:

// app/actions.ts
"use server";
import { wrapServerFunction } from '@sentry/react-router';

async function _updateUser(formData: FormData) {
  await db.users.update(formData.get('id'), { name: formData.get('name') });
}

export const updateUser = wrapServerFunction("updateUser", _updateUser);

Each invocation creates a dedicated span with op function.rsc.server_function and forceTransaction: true when no parent span exists.

Automatic Server Function Instrumentation

Added a Vite plugin that auto-wraps all exported functions in "use server" files. Opt-in only:

// vite.config.ts
sentryReactRouter({
  experimental_rscAutoInstrumentation: { enabled: true },
})

Uses AST parsing (recast + @babel/parser) to detect "use server" directives and exported functions. Skips files that already import wrapServerFunction. Server components are not auto-instrumented.

Also:

Added manifest-based route matching fallback in wrapSentryHandleRequest for RSC mode where staticHandlerContext.matches is not populated
Added no-op client-side stubs for wrapServerComponent and wrapServerFunction to prevent import errors
Added @babel/parser and recast as dependencies for AST parsing (Similar to SvelteKit)
Added E2E test application (react-router-7-rsc) covering server components, server functions, and performance spans

github-actions · 2026-01-20T13:35:56Z

node-overhead report 🧳

Note: This is a synthetic benchmark with a minimal express app and does not necessarily reflect the real-world performance impact in an application.

Scenario	Requests/s	% of Baseline	Prev. Requests/s	Change %
GET Baseline	8,809	-	8,843	-0%
GET With Sentry	1,487	17%	1,637	-9%
GET With Sentry (error only)	5,618	64%	5,887	-5%
POST Baseline	1,156	-	1,163	-1%
POST With Sentry	472	41%	547	-14%
POST With Sentry (error only)	1,001	87%	1,023	-2%
MYSQL Baseline	3,137	-	3,218	-3%
MYSQL With Sentry	259	8%	336	-23%
MYSQL With Sentry (error only)	2,538	81%	2,653	-4%

View base workflow run

chargome · 2026-02-02T15:16:06Z

@onurtemizkan sorry this one went under the radar. Can you resolve the conflict and ping me again?

onurtemizkan · 2026-02-04T00:54:04Z

@chargome, it's ready for review 👍

github-actions · 2026-02-04T01:01:41Z

Codecov Results 📊

Generated by Codecov Action

chargome

Generally LGTM to me but is there a way we could already wrap the server components with vite? Also initing the Client in a hook might happen quite late – any ideas if the client will eventually support an entry file?

chargome · 2026-02-04T11:04:30Z

packages/react-router/src/server/rsc/responseUtils.ts

+/**
+ * WeakSet to track errors that have been captured to avoid double-capture.
+ * Uses WeakSet so errors are automatically removed when garbage collected.
+ */
+const CAPTURED_ERRORS = new WeakSet<object>();


q: Why do we need this in here? We have a dedupe integration that should take of this I think?

packages/react-router/src/server/rsc/index.ts

packages/react-router/src/server/rsc/wrapMatchRSCServerRequest.ts

packages/react-router/src/server/rsc/wrapServerFunction.ts

packages/react-router/src/server/rsc/wrapServerComponent.ts

packages/react-router/src/server/rsc/wrapServerFunction.ts

packages/react-router/src/server/rsc/responseUtils.ts

packages/react-router/src/vite/makeAutoInstrumentRSCPlugin.ts

github-actions · 2026-02-19T20:00:50Z

size-limit report 📦

Path	Size	% Change	Change
@sentry/browser	25.62 kB	-	-
@sentry/browser - with treeshaking flags	24.12 kB	-	-
@sentry/browser (incl. Tracing)	42.42 kB	-	-
@sentry/browser (incl. Tracing, Profiling)	47.09 kB	-	-
@sentry/browser (incl. Tracing, Replay)	81.24 kB	-	-
@sentry/browser (incl. Tracing, Replay) - with treeshaking flags	70.86 kB	-	-
@sentry/browser (incl. Tracing, Replay with Canvas)	85.94 kB	-	-
@sentry/browser (incl. Tracing, Replay, Feedback)	98.2 kB	-	-
@sentry/browser (incl. Feedback)	42.43 kB	-	-
@sentry/browser (incl. sendFeedback)	30.29 kB	-	-
@sentry/browser (incl. FeedbackAsync)	35.34 kB	-	-
@sentry/browser (incl. Metrics)	26.79 kB	-	-
@sentry/browser (incl. Logs)	26.93 kB	-	-
@sentry/browser (incl. Metrics & Logs)	27.61 kB	-	-
@sentry/react	27.37 kB	-	-
@sentry/react (incl. Tracing)	44.76 kB	-	-
@sentry/vue	30.07 kB	-	-
@sentry/vue (incl. Tracing)	44.29 kB	-	-
@sentry/svelte	25.64 kB	-	-
CDN Bundle	28.16 kB	-	-
CDN Bundle (incl. Tracing)	43.25 kB	-	-
CDN Bundle (incl. Logs, Metrics)	29 kB	-	-
CDN Bundle (incl. Tracing, Logs, Metrics)	44.09 kB	-	-
CDN Bundle (incl. Replay, Logs, Metrics)	68.08 kB	-	-
CDN Bundle (incl. Tracing, Replay)	80.13 kB	-	-
CDN Bundle (incl. Tracing, Replay, Logs, Metrics)	80.99 kB	-	-
CDN Bundle (incl. Tracing, Replay, Feedback)	85.64 kB	-	-
CDN Bundle (incl. Tracing, Replay, Feedback, Logs, Metrics)	86.53 kB	-	-
CDN Bundle - uncompressed	82.34 kB	-	-
CDN Bundle (incl. Tracing) - uncompressed	128.06 kB	-	-
CDN Bundle (incl. Logs, Metrics) - uncompressed	85.18 kB	-	-
CDN Bundle (incl. Tracing, Logs, Metrics) - uncompressed	130.89 kB	-	-
CDN Bundle (incl. Replay, Logs, Metrics) - uncompressed	208.84 kB	-	-
CDN Bundle (incl. Tracing, Replay) - uncompressed	244.94 kB	-	-
CDN Bundle (incl. Tracing, Replay, Logs, Metrics) - uncompressed	247.76 kB	-	-
CDN Bundle (incl. Tracing, Replay, Feedback) - uncompressed	257.85 kB	-	-
CDN Bundle (incl. Tracing, Replay, Feedback, Logs, Metrics) - uncompressed	260.66 kB	-	-
@sentry/nextjs (client)	47.17 kB	-	-
@sentry/sveltekit (client)	42.88 kB	-	-
@sentry/node-core	52.18 kB	+0.02%	+9 B 🔺
@sentry/node	174.49 kB	+0.01%	+5 B 🔺
@sentry/node - without tracing	97.33 kB	+0.02%	+10 B 🔺
@sentry/aws-serverless	113.13 kB	+0.01%	+6 B 🔺

View base workflow run

packages/react-router/src/server/rsc/wrapServerComponent.ts

packages/react-router/src/server/rsc/wrapServerFunction.ts

packages/react-router/src/vite/makeAutoInstrumentRSCPlugin.ts

cursor · 2026-02-19T20:12:10Z

packages/react-router/src/vite/recastTypescriptParser.ts

+// - minor import and export changes
+// - merged the two files linked above into one for simplicity
+
+// Date of access: 2025-03-04


Incorrect date in source attribution comment

Low Severity

The comment states "Date of access: 2025-03-04" but today's date is 2026-02-19. This appears to be placeholder text or an incorrect timestamp that was accidentally left in the code during development. The date should either be corrected to reflect when the code was actually accessed, or removed if it's not meaningful.

packages/react-router/src/server/rsc/wrapServerComponent.ts

packages/react-router/src/vite/makeAutoInstrumentRSCPlugin.ts

packages/react-router/package.json

packages/react-router/src/vite/makeAutoInstrumentRSCPlugin.ts

packages/react-router/src/server/rsc/wrapServerComponent.ts

s1gr1d · 2026-02-26T15:18:23Z

packages/react-router/src/vite/types.ts

+  /**
+   * Enable debug logging to see which files are being instrumented.
+   * @default false
+   */
+  debug?: boolean;


Is there a specific reason, why there is another debug option? Would it be possible to use the one from the client options?

Updated 👍

packages/react-router/src/server/wrapSentryHandleRequest.ts

cursor · 2026-02-27T12:32:37Z

packages/react-router/src/server/rsc/wrapServerFunction.ts

+            [SEMANTIC_ATTRIBUTE_SENTRY_SOURCE]: 'route',
+            'rsc.server_function.name': functionName,
+            ...options.attributes,
+          },


Custom attributes can overwrite internal Sentry span attributes

Low Severity

In wrapServerFunction, ...options.attributes is spread after the internal Sentry attributes (SEMANTIC_ATTRIBUTE_SENTRY_OP, SEMANTIC_ATTRIBUTE_SENTRY_ORIGIN, SEMANTIC_ATTRIBUTE_SENTRY_SOURCE), allowing user-provided attributes to silently overwrite them. This could break span categorization and origin tracking. The spread order could be reversed so Sentry-internal attributes take precedence.

^{Triggered by project rule: PR Review Guidelines for Cursor Bot}

…strumentation

… for RSC mode

…lag in RSC wrappers

…instrumentation opt-in

…lugin

…tatus

cursor

Cursor Bugbot has reviewed your changes and found 1 potential issue.

^{Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, enable autofix in the Cursor dashboard.}

cursor · 2026-02-27T14:32:11Z

packages/react-router/src/server/wrapSentryHandleRequest.ts

+    else score += STATIC_SEGMENT_SCORE;
+  }
+  return score;
+}


Two iterations over segments array in computeScore

Low Severity

computeScore iterates segments twice: first with segments.includes('*') and then with the for...of loop. Since the * check within the loop already handles segment === '*' with continue, the splat penalty could be applied inside the same loop, consolidating both passes into one. This is on the request hot path in matchUrlToManifestRoute.

^{Triggered by project rule: PR Review Guidelines for Cursor Bot}

onurtemizkan force-pushed the onur/react-router-rsc-experimental branch 2 times, most recently from 159fb80 to 07fc2d6 Compare January 23, 2026 15:42

onurtemizkan force-pushed the onur/react-router-rsc-experimental branch from 07fc2d6 to c94138a Compare February 4, 2026 00:53

onurtemizkan marked this pull request as ready for review February 4, 2026 00:53

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feat(react-router): Add Experimental React Server Components (RSC) in…

1f1b759

…strumentation

onurtemizkan added 23 commits February 27, 2026 13:58

Fix RSC wrapper error handling and enable optional E2E tests

b20ff40

Add experimental flags

6b48970

Add client passthrough stubs for RSC wrappers and update E2E test app…

882e529

… for RSC mode

Update react-router to 7.12.0 in RSC test app

6e70dca

Handle 404 responses in RSC server function wrapper

ee30971

Add Vite plugin for automatic RSC server component instrumentation

79f9fb4

Replace custom WeakSet error dedup with SDK's __sentry_captured__ f…

6e73ff6

…lag in RSC wrappers

Remove unused RSC exports and dead types from public API

73c1000

Switch to AST parsing, keep server component manually instrumented

786a623

Use react_router.rsc mechanism type for RSC error capture

edfb9c0

Fix TypeScript build errors

a7ce5d8

Fix E2E type error in waitForError callbacks after rebase

8e39c93

Remove isAlreadyCaptured, clean up RSC tests and E2E app

a074b4f

Filter invalid identifier exports and add typeof guard in RSC utils

7446fa7

Clean up tests and docs

c5d70f5

Add manifest-based route matching fallback for RSC and make RSC auto-…

641051d

…instrumentation opt-in

Parameterize HTTP server span from wrapServerComponent in RSC mode

6ca735a

Lint

06ced60

Guard against non-function exports in wrapServerFunction

e2be218

Strip Vite query strings from module IDs in RSC plugin

ecf2e43

Inherit debug option from parent config in RSC auto-instrumentation p…

adf886c

…lugin

Use startSpanManual in wrapServerFunction to preserve redirect span s…

e83ff1a

…tatus

Guard against circular parentId references in resolveFullRoutePath

98cd9d4

onurtemizkan force-pushed the onur/react-router-rsc-experimental branch from 267d969 to 98cd9d4 Compare February 27, 2026 14:19

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onurtemizkan commented Jan 19, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Server Components

Server Functions

Automatic Server Function Instrumentation

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node-overhead report 🧳

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chargome commented Feb 2, 2026

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Codecov Results 📊

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size-limit report 📦

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Incorrect date in source attribution comment

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s1gr1d Feb 26, 2026

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Custom attributes can overwrite internal Sentry span attributes

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Two iterations over segments array in computeScore

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onurtemizkan commented Jan 19, 2026 •

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