Labsco
getsentry logo

sentry-svelte-sdk

โœ“ Officialโ˜… 19

by sentry ยท part of getsentry/sentry-agent-skills

Full Sentry SDK setup for Svelte and SvelteKit. Use when asked to "add Sentry to Svelte", "add Sentry to SvelteKit", "install @sentry/sveltekit", or configure error monitoring, tracing, session replay, or logging for Svelte or SvelteKit applications.

๐Ÿ”ฅ๐Ÿ”ฅ๐Ÿ”ฅ๐Ÿ”ฅโœ“ VerifiedAccount requiredAdvanced setup
๐Ÿงฉ One of 7 skills in the getsentry/sentry-agent-skills package โ€” works on its own, and pairs well with its siblings.

This is the playbook your agent receives when the skill activates โ€” you don't need to read it to use the skill, but it's here to audit before installing.

Sentry Svelte SDK

Opinionated wizard that scans your project and guides you through complete Sentry setup for Svelte and SvelteKit.

Invoke This Skill When

  • User asks to "add Sentry to Svelte" or "set up Sentry" in a Svelte/SvelteKit app
  • User wants error monitoring, tracing, session replay, or logging in Svelte or SvelteKit
  • User mentions @sentry/svelte, @sentry/sveltekit, or Sentry SDK for Svelte

Note: SDK versions and APIs below reflect current Sentry docs at time of writing (@sentry/sveltekit โ‰ฅ10.8.0, SvelteKit โ‰ฅ2.31.0). Always verify against docs.sentry.io/platforms/javascript/guides/sveltekit/ before implementing.


Phase 1: Detect

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

# Detect framework type
cat package.json | grep -E '"svelte"|"@sveltejs/kit"|"@sentry/svelte"|"@sentry/sveltekit"'

# Check for SvelteKit indicators
ls svelte.config.js svelte.config.ts vite.config.ts vite.config.js 2>/dev/null

# Check SvelteKit version (determines which setup pattern to use)
cat package.json | grep '"@sveltejs/kit"'

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

# Check existing hook files
ls src/hooks.client.ts src/hooks.client.js src/hooks.server.ts src/hooks.server.js \
   src/instrumentation.server.ts 2>/dev/null

# Detect logging libraries (Node side)
cat package.json | grep -E '"pino"|"winston"|"consola"'

# Detect if there's a backend (Go, Python, Ruby, etc.) in adjacent directories
ls ../backend ../server ../api 2>/dev/null
cat ../go.mod ../requirements.txt ../Gemfile 2>/dev/null | head -3

What to determine:

QuestionImpact
@sveltejs/kit in package.json?SvelteKit path vs. plain Svelte path
SvelteKit โ‰ฅ2.31.0?Modern (instrumentation.server.ts) vs. legacy setup
@sentry/sveltekit already present?Skip install, go straight to feature config
vite.config.ts present?Source map upload via Vite plugin available
Backend directory found?Trigger Phase 4 cross-link suggestion

Phase 2: Recommend

Present a concrete recommendation based on what you found. Don't ask open-ended questions โ€” lead with a proposal:

Recommended (core coverage):

  • โœ… Error Monitoring โ€” always; auto-captures unhandled errors on client and server
  • โœ… Tracing โ€” SvelteKit has both client-side navigation spans and server-side request spans; always recommend
  • โœ… Session Replay โ€” recommended for user-facing SvelteKit apps (client-side only)

Optional (enhanced observability):

  • โšก Logging โ€” structured logs via Sentry.logger.*; recommend when app uses server-side logging or needs log-to-trace correlation

Recommendation logic:

FeatureRecommend when...
Error MonitoringAlways โ€” non-negotiable baseline
TracingAlways for SvelteKit (client + server); for plain Svelte when calling APIs
Session ReplayUser-facing app, login flows, or checkout pages present
LoggingApp already uses server-side logging, or structured log search is needed

Propose: "I recommend setting up Error Monitoring + Tracing + Session Replay. Want me to also add structured Logging?"


Phase 3: Guide

Determine Setup Path

Your projectPackageSetup complexity
SvelteKit (โ‰ฅ2.31.0)@sentry/sveltekit5 files to create/modify
SvelteKit (<2.31.0)@sentry/sveltekit3 files (init in hooks.server.ts)
Plain Svelte (no @sveltejs/kit)@sentry/svelteSingle entry point

npx @sentry/wizard@latest -i sveltekit

The wizard walks you through login, org/project selection, and auth token setup interactively โ€” no manual token creation needed. It then installs the SDK, creates all necessary files (client/server hooks, Vite plugin config), configures source map upload, and adds a /sentry-example-page for verification. Skip to Verification after running it.

Option 2: Manual Setup

Step 1 โ€” Install

npm install @sentry/sveltekit --save

Step 2 โ€” svelte.config.js โ€” Enable instrumentation

import adapter from "@sveltejs/adapter-auto";

const config = {
  kit: {
    adapter: adapter(),
    experimental: {
      instrumentation: { server: true },
      tracing: { server: true },
    },
  },
};

export default config;

Step 3 โ€” src/instrumentation.server.ts โ€” Server-side init (runs once at startup)

import * as Sentry from "@sentry/sveltekit";

Sentry.init({
  dsn: process.env.SENTRY_DSN,
  environment: process.env.SENTRY_ENVIRONMENT,
  release: process.env.SENTRY_RELEASE,

  sendDefaultPii: true,
  tracesSampleRate: 1.0,    // lower to 0.1โ€“0.2 in production
  enableLogs: true,
});

Step 4 โ€” src/hooks.client.ts โ€” Client-side init

import * as Sentry from "@sentry/sveltekit";

Sentry.init({
  dsn: import.meta.env.PUBLIC_SENTRY_DSN ?? import.meta.env.VITE_SENTRY_DSN,
  environment: import.meta.env.MODE,

  sendDefaultPii: true,
  tracesSampleRate: 1.0,

  integrations: [
    Sentry.replayIntegration({
      maskAllText: true,
      blockAllMedia: true,
    }),
  ],

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

export const handleError = Sentry.handleErrorWithSentry();

Step 5 โ€” src/hooks.server.ts โ€” Server hooks (no init here in modern setup)

import * as Sentry from "@sentry/sveltekit";
import { sequence } from "@sveltejs/kit/hooks";

export const handleError = Sentry.handleErrorWithSentry();

// sentryHandle() instruments incoming requests and creates root spans
export const handle = Sentry.sentryHandle();

// If you have other handle functions, compose with sequence():
// export const handle = sequence(Sentry.sentryHandle(), myAuthHandle);

Step 6 โ€” vite.config.ts โ€” Source maps (requires SENTRY_AUTH_TOKEN)

import { sveltekit } from "@sveltejs/kit/vite";
import { sentrySvelteKit } from "@sentry/sveltekit";
import { defineConfig } from "vite";

export default defineConfig({
  plugins: [
    // sentrySvelteKit MUST come before sveltekit()
    sentrySvelteKit({
      org: process.env.SENTRY_ORG,
      project: process.env.SENTRY_PROJECT,
      authToken: process.env.SENTRY_AUTH_TOKEN,
    }),
    sveltekit(),
  ],
});

Add to .env (never commit):

SENTRY_AUTH_TOKEN=sntrys_...
SENTRY_ORG=my-org-slug
SENTRY_PROJECT=my-project-slug

Path B: SvelteKit Legacy (<2.31.0 or @sentry/sveltekit <10.8.0)

Skip instrumentation.server.ts and svelte.config.js changes. Instead, put Sentry.init() directly in hooks.server.ts:

// src/hooks.server.ts (legacy โ€” init goes here)
import * as Sentry from "@sentry/sveltekit";

Sentry.init({
  dsn: process.env.SENTRY_DSN,
  tracesSampleRate: 1.0,
  enableLogs: true,
});

export const handleError = Sentry.handleErrorWithSentry();
export const handle = Sentry.sentryHandle();

hooks.client.ts and vite.config.ts are identical to the modern path.


Path C: Plain Svelte (no SvelteKit)

Install:

npm install @sentry/svelte --save

Configure in entry point (src/main.ts or src/main.js) before mounting the app:

import * as Sentry from "@sentry/svelte";
import App from "./App.svelte";

Sentry.init({
  dsn: import.meta.env.VITE_SENTRY_DSN,
  environment: import.meta.env.MODE,

  sendDefaultPii: true,

  integrations: [
    Sentry.browserTracingIntegration(),
    Sentry.replayIntegration({
      maskAllText: true,
      blockAllMedia: true,
    }),
  ],

  tracesSampleRate: 1.0,
  tracePropagationTargets: ["localhost", /^https:\/\/yourapi\.io/],
  replaysSessionSampleRate: 0.1,
  replaysOnErrorSampleRate: 1.0,
  enableLogs: true,
});

const app = new App({ target: document.getElementById("app")! });
export default app;

Optional: Svelte component tracking (auto-injects tracking into all components):

// svelte.config.js
import { withSentryConfig } from "@sentry/svelte";

export default withSentryConfig(
  { compilerOptions: {} },
  { componentTracking: { trackComponents: true } }
);

For Each Agreed Feature

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

FeatureReferenceLoad when...
Error Monitoring${SKILL_ROOT}/references/error-monitoring.mdAlways (baseline)
Tracing${SKILL_ROOT}/references/tracing.mdAPI calls / distributed tracing needed
Session Replay${SKILL_ROOT}/references/session-replay.mdUser-facing app
Logging${SKILL_ROOT}/references/logging.mdStructured logs / log-to-trace correlation

For each feature: Read ${SKILL_ROOT}/references/<feature>.md, follow steps exactly, verify it works.


SvelteKit File Summary

FilePurposeModernLegacy
src/instrumentation.server.tsServer Sentry.init() โ€” runs once at startupโœ… RequiredโŒ
src/hooks.client.tsClient Sentry.init() + handleErrorโœ… Requiredโœ… Required
src/hooks.server.tshandleError + sentryHandle() (no init)โœ… Requiredโœ… Init goes here
svelte.config.jsEnable experimental.instrumentation.serverโœ… RequiredโŒ
vite.config.tssentrySvelteKit() plugin for source mapsโœ… Recommendedโœ… Recommended
.envSENTRY_AUTH_TOKEN, SENTRY_ORG, SENTRY_PROJECTโœ… For source mapsโœ… For source maps

Verification

After setup, trigger test events to confirm Sentry is receiving data:

<!-- src/routes/sentry-test/+page.svelte -->
<script>
  import * as Sentry from "@sentry/sveltekit";
</script>

<button onclick={() => { throw new Error("Sentry client test"); }}>
  Test Client Error
</button>

<button onclick={() => Sentry.captureMessage("Sentry test message", "info")}>
  Test Message
</button>
// src/routes/sentry-test/+server.ts
export const GET = () => {
  throw new Error("Sentry server test");
};

Check the Sentry dashboard:

  • Issues โ†’ both errors should appear within seconds
  • Traces โ†’ look for route-based transactions
  • Replays โ†’ session recording visible after page interaction
  • Logs โ†’ structured log entries (if logging enabled)

If nothing appears, set debug: true in Sentry.init() and check the browser/server console for SDK output.


After completing Svelte/SvelteKit setup, check for a companion backend missing Sentry coverage:

# Look for backend in adjacent directories
ls ../backend ../server ../api ../go ../python 2>/dev/null
cat ../go.mod 2>/dev/null | head -3
cat ../requirements.txt ../pyproject.toml 2>/dev/null | head -3
cat ../Gemfile 2>/dev/null | head -3

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

Backend detectedSuggest skill
Go (go.mod)sentry-go-sdk
Python (requirements.txt, pyproject.toml)sentry-python-sdk
Ruby (Gemfile)sentry-ruby-sdk
Node.js (Express, Fastify, etc.)Use @sentry/node โ€” see docs.sentry.io/platforms/javascript/guides/express/