sentry-cloudflare-sdk

All Skills > SDK Setup > Cloudflare SDK

Sentry Cloudflare SDK

Opinionated wizard that scans your Cloudflare project and guides you through complete Sentry setup for Workers, Pages, Durable Objects, Queues, Workflows, and Hono.

Invoke This Skill When

• User asks to "add Sentry to Cloudflare Workers" or "set up Sentry" in a Cloudflare project
• User wants to install or configure @sentry/cloudflare
• User wants error monitoring, tracing, logging, crons, or AI monitoring for Cloudflare Workers or Pages
• User asks about withSentry, sentryPagesPlugin, instrumentDurableObjectWithSentry, or instrumentD1WithSentry
• User wants to monitor Durable Objects, Queues, Workflows, Scheduled handlers, or Email handlers on Cloudflare

Note: SDK versions and APIs below reflect current Sentry docs at time of writing (@sentry/cloudflare v10.55.0). Always verify against docs.sentry.io/platforms/javascript/guides/cloudflare/ before implementing.

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Phase 1: Detect

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

# Detect Cloudflare project
ls wrangler.toml wrangler.jsonc wrangler.json 2>/dev/null

# Detect existing Sentry
cat package.json 2>/dev/null | grep -E '"@sentry/'

# Detect project type (Workers vs Pages)
ls functions/ functions/_middleware.js functions/_middleware.ts 2>/dev/null && echo "Pages detected"
cat wrangler.toml 2>/dev/null | grep -E 'main|pages_build_output_dir'

# Detect framework
cat package.json 2>/dev/null | grep -E '"hono"|"remix"|"astro"|"svelte"'

# Detect Durable Objects
cat wrangler.toml 2>/dev/null | grep -i 'durable_objects'

# Detect D1 databases
cat wrangler.toml 2>/dev/null | grep -i 'd1_databases'

# Detect Queues
cat wrangler.toml 2>/dev/null | grep -i 'queues'

# Detect Workflows
cat wrangler.toml 2>/dev/null | grep -i 'workflows'

# Detect Scheduled handlers (cron triggers)
cat wrangler.toml 2>/dev/null | grep -i 'crons\|triggers'

# Detect compatibility flags
cat wrangler.toml 2>/dev/null | grep -i 'compatibility_flags'
cat wrangler.jsonc 2>/dev/null | grep -i 'compatibility_flags'

# Detect AI/LLM libraries
cat package.json 2>/dev/null | grep -E '"openai"|"@anthropic-ai"|"ai"|"@google/generative-ai"|"@langchain"'

# Detect logging libraries
cat package.json 2>/dev/null | grep -E '"pino"|"winston"'

# Check for companion frontend
ls frontend/ web/ client/ 2>/dev/null
cat package.json 2>/dev/null | grep -E '"react"|"vue"|"svelte"|"next"'

What to determine:

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Phase 2: Recommend

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

Recommended (core coverage):

• ✅ Error Monitoring — always; captures unhandled exceptions in fetch, scheduled, queue, email, and Durable Object handlers
• ✅ Tracing — automatic HTTP request spans, outbound fetch tracing, D1 query spans

Optional (enhanced observability):

• ⚡ Logging — structured logs via Sentry.logger.*; recommend when log search is needed
• ⚡ Crons — detect missed/failed scheduled jobs; recommend when cron triggers are configured
• ⚡ D1 Instrumentation — automatic query spans and breadcrumbs; recommend when D1 is bound
• ⚡ Durable Objects — automatic error capture and spans for DO methods; recommend when DOs are configured
• ⚡ Workflows — automatic span creation for workflow steps; recommend when Workflows are configured
• ⚡ AI Monitoring — Vercel AI SDK, OpenAI, Anthropic, LangChain; recommend when AI libraries detected

Recommendation logic:

Propose: "I recommend setting up Error Monitoring + Tracing. Want me to also add D1 instrumentation and Crons monitoring?"

---

Phase 3: Guide

Option 1: Source Maps Wizard

You need to run this yourself — the wizard opens a browser for login and requires interactive input that the agent can't handle. Copy-paste into your terminal: `` npx @sentry/wizard@latest -i sourcemaps `` This sets up source map uploading so your production stack traces show readable code. It does not set up the SDK initialization — you still need to follow Option 2 below for the actual SDK setup. Once it finishes, continue with Option 2 for SDK setup.

Note: Unlike framework SDKs (Next.js, SvelteKit), there is no Cloudflare-specific wizard integration. The sourcemaps wizard only handles source map upload configuration.

---

Option 2: Manual Setup

Prerequisites: Compatibility Flags

The SDK requires AsyncLocalStorage. Add one of these flags to your Wrangler config:

wrangler.toml:

compatibility_flags = ["nodejs_als"]
# or: compatibility_flags = ["nodejs_compat"]

wrangler.jsonc:

{
  "compatibility_flags": ["nodejs_als"]
}

nodejs_als is lighter — it only enables AsyncLocalStorage. Use nodejs_compat if your code also needs other Node.js APIs.

Install

npm install @sentry/cloudflare

Workers Setup

Wrap your handler with withSentry. This automatically instruments fetch, scheduled, queue, email, and tail handlers:

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

export default Sentry.withSentry(
  (env: Env) => ({
    dsn: env.SENTRY_DSN,
    sendDefaultPii: true,
    tracesSampleRate: 1.0,
    enableLogs: true,
  }),
  {
    async fetch(request, env, ctx) {
      return new Response("Hello World!");
    },
  } satisfies ExportedHandler<Env>,
);

Key points:

• The first argument is a callback that receives env — use this to read secrets like SENTRY_DSN
• The SDK reads DSN, environment, release, debug, tunnel, and traces sample rate from env automatically (see Environment Variables)
• withSentry wraps all exported handlers — you do not need separate wrappers for scheduled, queue, etc.

Pages Setup

Use sentryPagesPlugin as middleware:

// functions/_middleware.ts
import * as Sentry from "@sentry/cloudflare";

export const onRequest = Sentry.sentryPagesPlugin((context) => ({
  dsn: context.env.SENTRY_DSN,
  sendDefaultPii: true,
  tracesSampleRate: 1.0,
  enableLogs: true,
}));

Chaining multiple middlewares:

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

export const onRequest = [
  // Sentry must be first
  Sentry.sentryPagesPlugin((context) => ({
    dsn: context.env.SENTRY_DSN,
    tracesSampleRate: 1.0,
  })),
  // Add more middlewares here
];

Using wrapRequestHandler directly (for frameworks like SvelteKit on Cloudflare Pages):

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

export const handle = ({ event, resolve }) => {
  return Sentry.wrapRequestHandler(
    {
      options: {
        dsn: event.platform.env.SENTRY_DSN,
        tracesSampleRate: 1.0,
      },
      request: event.request,
      context: event.platform.ctx,
    },
    () => resolve(event),
  );
};

Hono on Cloudflare Workers

Recommended (v10.55.0+): Use the standalone @sentry/hono package for Hono apps:

npm install @sentry/hono @sentry/cloudflare

The @sentry/cloudflare package is a peer dependency and must stay in sync with @sentry/hono.

import { Hono } from "hono";
import { sentry } from "@sentry/hono/cloudflare";

type Bindings = { SENTRY_DSN: string };

const app = new Hono<{ Bindings: Bindings }>();

// Initialize Sentry middleware as early as possible
app.use(
  sentry(app, (env) => ({
    dsn: env.SENTRY_DSN,
    tracesSampleRate: 1.0,
  })),
);

app.get("/", (ctx) => ctx.json({ message: "Hello" }));

app.get("/error", () => {
  throw new Error("Test error");
});

export default app;

The sentry() middleware automatically captures errors and creates transaction spans with route patterns.

Legacy approach (deprecated): Using @sentry/cloudflare with withSentry still works, but honoIntegration is deprecated:

import { Hono } from "hono";
import * as Sentry from "@sentry/cloudflare";

const app = new Hono();

app.get("/", (ctx) => ctx.json({ message: "Hello" }));

export default Sentry.withSentry(
  (env: Env) => ({
    dsn: env.SENTRY_DSN,
    tracesSampleRate: 1.0,
  }),
  app,
);

Set Up the SENTRY_DSN Secret

Store your DSN as a Cloudflare secret — do not hardcode it:

# Local development: add to .dev.vars
echo 'SENTRY_DSN="https://examplePublicKey@o0.ingest.sentry.io/0"' >> .dev.vars

# Production: set as a secret
npx wrangler secret put SENTRY_DSN

Add the binding to your Env type:

interface Env {
  SENTRY_DSN: string;
  // ... other bindings
}

Source Maps Setup

Source maps make production stack traces readable. Without them, you see minified/bundled code.

Step 1: Generate a Sentry auth token

Go to sentry.io/settings/auth-tokens/ and create a token with project:releases and org:read scopes.

Step 2: Install the Sentry Vite plugin (most Cloudflare projects use Vite via Wrangler):

npm install @sentry/vite-plugin --save-dev

Step 3: Configure vite.config.ts (if your project has one):

import { defineConfig } from "vite";
import { sentryVitePlugin } from "@sentry/vite-plugin";

export default defineConfig({
  build: {
    sourcemap: true,
  },
  plugins: [
    sentryVitePlugin({
      org: "___ORG_SLUG___",
      project: "___PROJECT_SLUG___",
      authToken: process.env.SENTRY_AUTH_TOKEN,
    }),
  ],
});

Step 4: Set environment variables in CI

SENTRY_AUTH_TOKEN=sntrys_eyJ...
SENTRY_ORG=my-org
SENTRY_PROJECT=my-project

Step 5: Add to .gitignore

.dev.vars
.env.sentry-build-plugin

---

Automatic Release Detection

The SDK can automatically detect the release version via Cloudflare's version metadata binding:

wrangler.toml:

[version_metadata]
binding = "CF_VERSION_METADATA"

Release priority (highest to lowest):

1. release option passed to Sentry.init()
2. SENTRY_RELEASE environment variable
3. CF_VERSION_METADATA.id binding

---

For Each Agreed Feature

Load the corresponding reference file and follow its steps:

For each feature: read the reference file, follow its steps exactly, and verify before moving on.

---

Verification

After setup, verify Sentry is working:

// Add temporarily to your fetch handler, then remove
export default Sentry.withSentry(
  (env: Env) => ({
    dsn: env.SENTRY_DSN,
    tracesSampleRate: 1.0,
  }),
  {
    async fetch(request, env, ctx) {
      throw new Error("Sentry test error — delete me");
    },
  } satisfies ExportedHandler<Env>,
);

Deploy and trigger the route, then check your Sentry Issues dashboard — the error should appear within ~30 seconds.

Verification checklist:

---

Config Reference

Sentry.init() Options

Environment Variables (Read from env)

The SDK reads these from the Cloudflare env object automatically:

Default Integrations

These are registered automatically by getDefaultIntegrations():

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Phase 4: Cross-Link

After completing Cloudflare setup, check for companion services:

# Check for companion frontend
ls frontend/ web/ client/ ui/ 2>/dev/null
cat package.json 2>/dev/null | grep -E '"react"|"vue"|"svelte"|"next"|"astro"'

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

If a frontend is found, suggest the matching SDK skill:

If a backend is found in a different directory:

Connecting frontend and backend with linked Sentry projects enables distributed tracing — stack traces that span your browser, Cloudflare Worker, and backend API in a single trace view.

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Troubleshooting