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 instrumentation for React Router v7.9.0+ React Server Components (RSC).

React Router's RSC support is currently behind unstable_reactRouterRSC() and subject to change. These wrappers provide error capture and performance tracing for RSC server requests, server components, and server functions.

RSC Request Handlers

Added wrapMatchRSCServerRequest() and wrapRouteRSCServerRequest():

wrapMatchRSCServerRequest - Wraps RSC server matching with spans for generateResponse and loadServerAction
wrapRouteRSCServerRequest - Wraps SSR request handling with spans for fetchServer and renderHTML

// rsc-handler.ts
import {
  unstable_matchRSCServerRequest as matchRSCServerRequest,
  unstable_routeRSCServerRequest as routeRSCServerRequest,
} from "react-router";
import { wrapMatchRSCServerRequest, wrapRouteRSCServerRequest } from "@sentry/react-router";

const sentryMatchRSCServerRequest = wrapMatchRSCServerRequest(matchRSCServerRequest);
const sentryRouteRSCServerRequest = wrapRouteRSCServerRequest(routeRSCServerRequest);

Server Components

Added wrapServerComponent() for error instrumentation:

// routes/users.$id.tsx
import { wrapServerComponent } from "@sentry/react-router";

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

export const ServerComponent = wrapServerComponent(_UserPage, {
  componentRoute: "/users/:id",
  componentType: "Page",
});

Redirect (3xx) and not-found (404) responses are not captured as errors.

Server Functions

Added wrapServerFunction() and wrapServerFunctions() for "use server" functions:

// 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);

Needs docs PR

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	9,038	-	8,903	+2%
GET With Sentry	1,711	19%	1,745	-2%
GET With Sentry (error only)	6,196	69%	6,222	-0%
POST Baseline	1,202	-	1,223	-2%
POST With Sentry	598	50%	590	+1%
POST With Sentry (error only)	1,058	88%	1,069	-1%
MYSQL Baseline	3,334	-	3,336	-0%
MYSQL With Sentry	513	15%	496	+3%
MYSQL With Sentry (error only)	2,722	82%	2,696	+1%

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?

cursor · 2026-02-05T16:29:59Z

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

+export { wrapServerFunction } from './wrapServerFunction';
+export { wrapServerComponent } from './wrapServerComponent';
+
+export type { ServerComponentContext, WrapServerFunctionOptions } from './types';


RSC request handler wrappers not exported from package

Medium Severity

The PR description documents wrapMatchRSCServerRequest, wrapRouteRSCServerRequest, and wrapServerFunctions as public APIs with usage examples showing imports from @sentry/react-router. However, these functions are implemented in their respective files but not exported from packages/react-router/src/server/rsc/index.ts. Only wrapServerFunction and wrapServerComponent are exported. Users following the documentation will get import errors when trying to use the RSC request handler wrappers.

Additional Locations (1)

packages/react-router/src/server/index.ts#L21-L25

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

…strumentation

… for RSC mode

…lag in RSC wrappers

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

cursor

Cursor Bugbot has reviewed your changes and found 2 potential issues.

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

cursor · 2026-02-06T17:24:04Z

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

+  } catch {
+    return false;
+  }
+}


Redundant isAlreadyCaptured duplicates captureException internal dedup

Low Severity

The isAlreadyCaptured function in responseUtils.ts duplicates dedup logic already internal to captureException. The core SDK's captureException calls checkOrSetAlreadyCaught (in packages/core/src/client.ts), which checks __sentry_captured__ and returns early if the error was already captured. This makes the pre-check in wrapServerComponent and wrapServerFunction redundant and introduces a maintenance risk if the core SDK's property name or logic changes. The PR reviewer @chargome also flagged this.

Additional Locations (1)

packages/react-router/src/server/rsc/wrapServerComponent.ts#L103-L116

cursor · 2026-02-06T17:24:04Z

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

+      }
+      return false;
+    },
+  });


Auto-instrumentation silently drops export * re-exports

Medium Severity

The recast.visit call in analyzeModule handles visitExportDefaultDeclaration and visitExportNamedDeclaration but has no visitExportAllDeclaration handler. When a "use server" file uses export * from './other-actions' alongside direct exports, the transform hook completely replaces the file content with generated wrapper code that only includes the directly declared exports. The export * re-exports are silently dropped, causing those functions to become unavailable at runtime.

Additional Locations (1)

packages/react-router/src/vite/makeAutoInstrumentRSCPlugin.ts#L293-L304

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

chargome reviewed Feb 4, 2026

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cursor bot reviewed Feb 5, 2026

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packages/react-router/src/server/rsc/wrapServerFunction.ts Show resolved Hide resolved

onurtemizkan added 11 commits February 6, 2026 16:13

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

5778e6b

…strumentation

Fix RSC wrapper error handling and enable optional E2E tests

c2063ff

Add experimental flags

c2c7926

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

d65edf6

… for RSC mode

Update react-router to 7.12.0 in RSC test app

843b277

Handle 404 responses in RSC server function wrapper

d402ccb

Add Vite plugin for automatic RSC server component instrumentation

72f31b6

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

5e93086

…lag in RSC wrappers

Remove unused RSC exports and dead types from public API

3e46675

Switch to AST parsing, keep server component manually instrumented

5c04b8d

Use react_router.rsc mechanism type for RSC error capture

141002a

onurtemizkan force-pushed the onur/react-router-rsc-experimental branch from 7954e55 to 141002a Compare February 6, 2026 16:17

sentry bot reviewed Feb 6, 2026

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packages/react-router/src/server/rsc/wrapServerFunction.ts Show resolved Hide resolved

onurtemizkan added 2 commits February 6, 2026 16:38

Fix TypeScript build errors

c805760

Fix E2E type error in waitForError callbacks after rebase

e10f4e4

cursor bot reviewed Feb 6, 2026

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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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RSC Request Handlers

Server Components

Server Functions

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node-overhead report 🧳

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chargome commented Feb 2, 2026

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RSC request handler wrappers not exported from package

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Redundant isAlreadyCaptured duplicates captureException internal dedup

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Auto-instrumentation silently drops export * re-exports

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onurtemizkan commented Jan 19, 2026 •

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Redundant `isAlreadyCaptured` duplicates `captureException` internal dedup

Auto-instrumentation silently drops `export *` re-exports