All Skills > SDK Setup > TanStack Start React SDK

Sentry TanStack Start React SDK

Opinionated wizard that scans your TanStack Start React project and guides you through complete Sentry setup for browser and server runtimes.

Invoke This Skill When

User asks to "add Sentry to TanStack Start" or "set up Sentry" in a TanStack Start React app
User wants to install or configure
```
@sentry/tanstackstart-react
```
User wants error monitoring, tracing, session replay, logs, or user feedback for TanStack Start React
User asks about
```
sentryTanstackStart
```
,
```
wrapFetchWithSentry
```
,
```
instrument.server.mjs
```
, or TanStack Start middleware instrumentation

Note: This SDK is currently alpha and documented as compatible with TanStack Start
1.0 RC
. Always verify against docs.sentry.io/platforms/javascript/guides/tanstackstart-react/ before implementing.

Phase 1: Detect

Run these commands to understand the project before making any recommendations:

bash

# Detect TanStack Start / Router and existing Sentry
cat package.json | grep -E '"@tanstack/react-start"|"@tanstack/react-router"|"@sentry/tanstackstart-react"'

# Check if Sentry is already present
cat package.json | grep '"@sentry/'

# Detect key files used by the TanStack Start setup
ls src/router.tsx src/start.ts src/server.ts instrument.server.mjs vite.config.ts vite.config.js 2>/dev/null

# Check whether source map upload credentials are configured
cat .env .env.local .env.sentry-build-plugin 2>/dev/null | grep "SENTRY_AUTH_TOKEN"

# Detect deployment hints in scripts
cat package.json | grep -E '"dev"|"build"|"start"|NODE_OPTIONS|--import'

# Detect logging libraries
cat package.json | grep -E '"pino"|"winston"|"loglevel"'

# Detect companion backend directories
ls ../backend ../server ../api 2>/dev/null
cat ../go.mod ../requirements.txt ../Gemfile ../pom.xml 2>/dev/null | head -3

What to determine:

Question	Impact
`@tanstack/react-start` present?	Confirms this skill is the right setup path
`@sentry/tanstackstart-react` already installed?	Skip install and go to feature tuning
`src/router.tsx` exists?	Client-side `Sentry.init` placement
`src/start.ts` exists?	Global middleware setup for server-side errors
`src/server.ts` exists?	Server entry instrumentation placement
`instrument.server.mjs` exists?	Runtime startup instrumentation path
`vite.config.ts` exists?	Add `sentryTanstackStart` plugin and source maps
`SENTRY_AUTH_TOKEN` configured?	Source map upload readiness
Backend directory found?	Trigger Phase 4 cross-link suggestion

Phase 2: Recommend

Present a concrete recommendation based on what you found. Do not ask open-ended questions — lead with a proposal:

Recommended (core coverage):

✅ Error Monitoring — always; captures unhandled client and server errors
✅ Tracing — high-value for request and route timing across browser and server
✅ Session Replay — recommended for user-facing apps

Optional (enhanced observability):

⚡ Logs — recommend when structured log search and log-to-trace correlation are needed
⚡ User Feedback — recommend when product teams want in-app issue reports

Recommendation logic:

Feature	Recommend when...
Error Monitoring	Always — non-negotiable baseline
Tracing	Usually yes for TanStack Start; route + fetch instrumentation gives immediate value
Session Replay	User-facing app, login flows, checkout flows, or hard-to-reproduce UX bugs
Logs	Existing logging strategy, support workflow, or trace/log correlation needs
User Feedback	Team wants direct user reports without leaving the app

Propose: "I recommend Error Monitoring + Tracing + Session Replay. Want me to also enable Logs and User Feedback?"

Phase 3: Guide

Install

bash

npm install @sentry/tanstackstart-react --save

Configure Client-Side Sentry in

src/router.tsx

Initialize Sentry inside the router factory and gate it to the browser:

tsx

import * as Sentry from "@sentry/tanstackstart-react";
import { createRouter } from "@tanstack/react-router";

export const getRouter = () => {
  const router = createRouter();

  if (!router.isServer) {
    Sentry.init({
      dsn: "___PUBLIC_DSN___",
      sendDefaultPii: true,

      integrations: [
        Sentry.tanstackRouterBrowserTracingIntegration(router),
        Sentry.replayIntegration(),
        Sentry.feedbackIntegration({
          colorScheme: "system",
        }),
      ],

      enableLogs: true,
      tracesSampleRate: 1.0,
      replaysSessionSampleRate: 0.1,
      replaysOnErrorSampleRate: 1.0,
    });
  }

  return router;
};

Configure Server-Side Sentry in

instrument.server.mjs

Create

instrument.server.mjs

in project root:

javascript

import * as Sentry from "@sentry/tanstackstart-react";

Sentry.init({
  dsn: "___PUBLIC_DSN___",
  sendDefaultPii: true,
  enableLogs: true,
  tracesSampleRate: 1.0,
});

Configure Vite Plugin in

vite.config.ts

sentryTanstackStart

should be the last plugin:

typescript

import { defineConfig } from "vite";
import { sentryTanstackStart } from "@sentry/tanstackstart-react/vite";
import { tanstackStart } from "@tanstack/react-start/plugin/vite";

export default defineConfig({
  plugins: [
    tanstackStart(),
    sentryTanstackStart({
      org: "___ORG_SLUG___",
      project: "___PROJECT_SLUG___",
      authToken: process.env.SENTRY_AUTH_TOKEN,
    }),
  ],
});

If the token is stored in

.env

, load it with

loadEnv

in the Vite config before passing it to the plugin.

Instrument Server Entry Point in

src/server.ts

Wrap the fetch handler with

wrapFetchWithSentry

typescript

import { wrapFetchWithSentry } from "@sentry/tanstackstart-react";
import handler, { createServerEntry } from "@tanstack/react-start/server-entry";

export default createServerEntry(
  wrapFetchWithSentry({
    fetch(request: Request) {
      return handler.fetch(request);
    },
  }),
);

Add Global Server Middleware in

src/start.ts

These middleware capture server-side request and function errors:

tsx

import {
  sentryGlobalFunctionMiddleware,
  sentryGlobalRequestMiddleware,
} from "@sentry/tanstackstart-react";
import { createStart } from "@tanstack/react-start";

export const startInstance = createStart(() => {
  return {
    requestMiddleware: [sentryGlobalRequestMiddleware],
    functionMiddleware: [sentryGlobalFunctionMiddleware],
  };
});

Sentry middleware should be first in each array.

Runtime Startup Patterns

Choose one runtime method:

Runtime pattern	Use when...	Notes
`--import` flag	You can control Node startup flags	Preferred for production monitoring
Direct import in `src/server.ts`	Host restricts startup flags (for example serverless hosts)	Limits instrumentation to native Node APIs

--import

examples:

json

{
  "scripts": {
    "dev": "NODE_OPTIONS='--import ./instrument.server.mjs' vite dev --port 3000",
    "build": "vite build && cp instrument.server.mjs .output/server",
    "start": "node --import ./.output/server/instrument.server.mjs .output/server/index.mjs"
  }
}

Direct import fallback (top of

src/server.ts

typescript

import "../instrument.server.mjs";

For Each Agreed Feature

Walk through features one at a time. Load the reference file, follow steps exactly, and verify before moving on:

Feature	Reference	Load when...
Error Monitoring	`${SKILL_ROOT}/references/error-monitoring.md`	Always
Tracing	`${SKILL_ROOT}/references/tracing.md`	Route/API performance visibility needed
Session Replay	`${SKILL_ROOT}/references/session-replay.md`	User-facing app
Logs	`${SKILL_ROOT}/references/logging.md`	Structured logs and correlation needed
User Feedback	`${SKILL_ROOT}/references/user-feedback.md`	In-app feedback collection needed
TanStack Start Features	`${SKILL_ROOT}/references/tanstackstart-features.md`	Server entry, Vite plugin, source maps, runtime startup

For each feature:

Read ${SKILL_ROOT}/references/<feature>.md

, follow steps exactly, verify it works.

Configuration Reference

Key

Sentry.init()

Options

Option	Type	Default	Notes
`dsn`	`string`	—	Required; SDK is disabled when empty
`sendDefaultPii`	`boolean`	`false`	Sends request headers and IP-derived user context
`integrations`	`Integration[]`	SDK defaults	Include TanStack Router tracing, replay, feedback as needed
`enableLogs`	`boolean`	`false`	Enables `Sentry.logger.*` APIs
`tracesSampleRate`	`number`	—	`1.0` in development, lower in production
`replaysSessionSampleRate`	`number`	—	Fraction of all sessions recorded
`replaysOnErrorSampleRate`	`number`	—	Fraction of error sessions recorded
`tunnel`	`string`	—	Optional ad-blocker bypass endpoint
`debug`	`boolean`	`false`	SDK diagnostic logging

TanStack Start-Specific APIs

API	Purpose
`tanstackRouterBrowserTracingIntegration(router)`	Browser navigation tracing
`wrapFetchWithSentry(...)`	Server request tracing + error capture on fetch handler
`sentryGlobalRequestMiddleware`	Captures request-level server errors
`sentryGlobalFunctionMiddleware`	Captures server function errors
`sentryTanstackStart({...})`	Vite plugin for source maps and middleware instrumentation

Verification

Trigger test events to confirm Sentry receives data.

Issues Test (Frontend)

tsx

<button
  type="button"
  onClick={() => {
    throw new Error("Sentry Test Error");
  }}
>
  Break the world
</button>

Tracing Test (Frontend + API Route)

tsx

<button
  type="button"
  onClick={async () => {
    await Sentry.startSpan({ name: "Example Frontend Span", op: "test" }, async () => {
      const res = await fetch("/api/sentry-example");
      if (!res.ok) {
        throw new Error("Sentry Example Frontend Error");
      }
    });
  }}
>
  Break the world
</button>

Logs Test

javascript

Sentry.logger.info("User example action completed");
Sentry.logger.warn("Slow operation detected", { operation: "data_fetch", duration: 3500 });
Sentry.logger.error("Validation failed", { field: "email", reason: "Invalid email" });

Confirm in Sentry:

Issues: frontend/server errors appear
Traces: browser and server spans appear
Replays: session replay appears when enabled
Logs: log lines appear when
```
enableLogs: true
```
User Feedback: submissions appear when feedback integration is enabled

Phase 4: Cross-Link

After completing TanStack Start setup, check whether a companion backend exists without Sentry:

bash

ls ../backend ../server ../api ../go ../python 2>/dev/null
cat ../go.mod ../requirements.txt ../pyproject.toml ../Gemfile ../pom.xml 2>/dev/null | head -5

If a backend exists without Sentry configured, suggest the matching skill:

Backend detected	Suggest skill
Go ( `go.mod` )	`sentry-go-sdk`
Python ( `requirements.txt` , `pyproject.toml` )	`sentry-python-sdk`
Ruby ( `Gemfile` )	`sentry-ruby-sdk`
Java ( `pom.xml` , `build.gradle` )	Use `@sentry/java` docs
Node.js backend services	`sentry-node-sdk`

Troubleshooting

Issue	Solution
Events not appearing	Set `debug: true` , verify DSN, and ensure client/server init files both run
No server traces	Confirm `src/server.ts` uses `wrapFetchWithSentry` and runtime loads `instrument.server.mjs`
Server errors missing from route handlers	Ensure `sentryGlobalRequestMiddleware` and `sentryGlobalFunctionMiddleware` are first in arrays
Source maps not resolving	Verify `SENTRY_AUTH_TOKEN` , `org` , and `project` in `sentryTanstackStart` config
`SENTRY_AUTH_TOKEN` undefined in Vite config	Use `loadEnv(mode, process.cwd(), "")` or `.env.sentry-build-plugin`
Replay not recording	Ensure `replayIntegration()` is in `integrations` and sample rates are non-zero
Feedback widget not visible	Confirm `feedbackIntegration()` is configured and check CSS z-index conflicts
Logs missing in Sentry	Set `enableLogs: true` and use `Sentry.logger.*` APIs
Direct-import setup misses library spans	Prefer `--import` startup when possible; direct import supports native Node instrumentation only
SSR rendering exceptions not auto-captured	Capture manually with `Sentry.captureException` in error boundaries / fallback handlers

sentry-tanstack-start-sdk

NPX Install

Tags

SKILL.md Content

Sentry TanStack Start React SDK

Invoke This Skill When

Phase 1: Detect

Phase 2: Recommend

Phase 3: Guide

Install

Configure Client-Side Sentry in
`src/router.tsx`

Configure Server-Side Sentry in
`instrument.server.mjs`

Configure Vite Plugin in
`vite.config.ts`

Instrument Server Entry Point in
`src/server.ts`

Add Global Server Middleware in
`src/start.ts`

Runtime Startup Patterns

For Each Agreed Feature

Configuration Reference

Key
`Sentry.init()`
Options

TanStack Start-Specific APIs

Verification

Issues Test (Frontend)

Tracing Test (Frontend + API Route)

Logs Test

Phase 4: Cross-Link

Troubleshooting