Cloudflare

Learn how to manually set up Sentry for Cloudflare Workers and capture your first errors.

Agent-Assisted Setup
Use curl to download, read and follow https://skills.sentry.dev/instrument to set up the Sentry Cloudflare SDK.
Your agent will set up Sentry in your Cloudflare app automatically. Works with Cursor, Claude Code, Codex, and more.View docs ↗
Install the full plugin

Install the Sentry plugin to give your assistant every skill. See the installation docs for more details.

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npx @sentry/agent-plugin install

This guide covers Cloudflare Workers. If you're deploying a Cloudflare Pages application, see Cloudflare Pages instead, which is set up with middleware rather than a wrapper.

If you're using any of the listed frameworks, follow their specific setup instructions:

You need:

Choose the features you want to configure, and this guide will show you how:

Want to learn more about these features?
  • Issues (always enabled): Sentry's core error monitoring product that automatically reports errors, uncaught exceptions, and unhandled rejections. If you have something that looks like an exception, Sentry can capture it.
  • Tracing: Track software performance while seeing the impact of errors across multiple systems. For example, distributed tracing allows you to follow a request from the frontend to the backend and back.
  • Logs: Centralize and analyze your application logs to correlate them with errors and performance issues. Search, filter, and visualize log data to understand what's happening in your applications.
  • Application Metrics (always enabled): Track and analyze custom application metrics, such as response times and database query durations, to understand trends and patterns in your application's performance and behavior over time.

Run the command for your preferred package manager to add the Sentry SDK to your application:

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npm install @sentry/cloudflare --save

This guide sets Sentry up through Vite, which is what we recommend for Cloudflare Workers. The plugin does the wiring at build time, so your Worker code stays untouched.

Add the Sentry plugin to your existing vite.config.ts, next to cloudflare(). Both of its behaviors are on by default.

autoInstrumentation wraps your Worker entry, and any Durable Object, Workflow or Agents SDK class in your wrangler config, at build time, so you don't have to call Sentry.withSentry() yourself. buildTimeInstrumentation instruments bundled dependencies such as database clients, which is the only way to trace them in the Workers runtime, where the SDK can't patch them at runtime.

To see its options, which packages it instruments, and how to opt out of either behavior, see Vite Plugin.

vite.config.ts
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 import { cloudflare } from "@cloudflare/vite-plugin";
+import { sentryCloudflareVitePlugin } from "@sentry/cloudflare/vite";
 import { defineConfig } from "vite";

 export default defineConfig({
   plugins: [
     cloudflare(),
+    sentryCloudflareVitePlugin(),
   ],
 });

Run vite build before wrangler deploy, and use vite dev in place of wrangler dev for local development.

Since the SDK needs access to the AsyncLocalStorage API, you need to set the nodejs_compat compatibility flag and a compatibility_date of 2024-09-23 or later in your wrangler.(jsonc|toml) configuration file. We recommend the latest compatibility date, as some integrations depend on newer Cloudflare runtime features:

wrangler.jsonc
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{
  // Set this to today's date
  "compatibility_date": "2026-09-25",
  "compatibility_flags": ["nodejs_compat"],
}

If you don't set the release option manually, the SDK automatically detects it from these sources (in order of priority):

  1. The SENTRY_RELEASE environment variable
  2. The CF_VERSION_METADATA.id binding (if configured)

To enable automatic release detection via Cloudflare's version metadata, add the CF_VERSION_METADATA binding in your wrangler configuration. This provides access to the Cloudflare version metadata.

wrangler.jsonc
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{
  // ...
  "version_metadata": {
    "binding": "CF_VERSION_METADATA",
  },
}

Create an instrument.server.ts file next to your Worker entry, the file that main points at in your wrangler config. If main is src/index.ts, the file belongs at src/instrument.server.ts, not at the project root.

The name is fixed. The plugin looks for instrument.server with a .ts, .mts, .js, .mjs or .cjs extension, and passes its default export to withSentry. Use defineCloudflareOptions to get the options type-checked.

src/instrument.server.ts
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import { defineCloudflareOptions } from "@sentry/cloudflare";

export default defineCloudflareOptions((env) => ({
  dsn: "___PUBLIC_DSN___",

  dataCollection: {
    // Any dataCollection object (including {}) uses permissive defaults:
    // userInfo, cookies, HTTP bodies, genAI prompts/responses, and more.
    // Uncomment to tighten. Details:
    // https://docs.sentry.io/platforms/javascript/guides/cloudflare/configuration/options/#dataCollection
    // userInfo: false,
    // httpBodies: [],
    // genAI: { inputs: false, outputs: false },
  },
  // ___PRODUCT_OPTION_START___ performance

  // Set tracesSampleRate to 1.0 to capture 100% of spans for tracing.
  // Learn more at
  // https://docs.sentry.io/platforms/javascript/guides/cloudflare/configuration/options/#tracesSampleRate
  tracesSampleRate: 1.0,
  // ___PRODUCT_OPTION_END___ performance
}));
Prefer to configure Sentry with bindings?

If you don't add an instrument.server.* file, the SDK reads its configuration from the Worker's env at runtime instead: SENTRY_DSN, SENTRY_ENVIRONMENT, SENTRY_TRACES_SAMPLE_RATE, SENTRY_DEBUG, SENTRY_TUNNEL and SENTRY_TRACE_LIFECYCLE. Set them as secrets or vars in your wrangler config.

The stack traces in your Sentry errors probably won't look like your actual code without unminifying them. To fix this, upload your source maps to Sentry.

First, set the upload_source_maps option to true in your wrangler.(jsonc|toml) config file to enable source map uploading:

wrangler.jsonc
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{
  "upload_source_maps": true,
}

Next, run the Sentry Wizard to finish your setup:

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npx @sentry/wizard@latest -i sourcemaps

By default, the SDK sends user identity data (IP address, ID, and similar) and other data like HTTP bodies and URL query parameters. This will give you rich debugging context.

The SDK always filters sensitive values whose keys match a built-in denylist, such as auth or password, and sends [Filtered] instead.

To send less data, turn off the categories you don't need in the dataCollection option. For the full list of categories and their defaults, see the dataCollection options.

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Sentry.init({
  dsn: "___PUBLIC_DSN___",

  dataCollection: {
    userInfo: false,
    // other categories

  },
});

Let's test your setup and confirm that Sentry is working correctly and sending data to your Sentry project.

First, let's make sure Sentry is correctly capturing errors and creating issues in your project.

Add the following code snippet to your main worker file to create a /debug-sentry route that triggers an error when called:

index.js
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export default {
  async fetch(request) {
    const url = new URL(request.url);

    if (url.pathname === "/debug-sentry") {
      throw new Error("My first Sentry error!");
    }

    // Your existing routes and logic here...
    return new Response("...");
  },
};

To test your tracing configuration, update the previous code snippet by starting a trace to measure the time it takes to run your code.

index.js
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import * as Sentry from "@sentry/cloudflare";

export default {
  async fetch(request) {
    const url = new URL(request.url);

    if (url.pathname === "/debug-sentry") {
      await Sentry.startSpan(
        {
          op: "test",
          name: "My First Test Span",
        },
        async () => {
          await new Promise((resolve) => setTimeout(resolve, 100)); // Wait for 100ms
          throw new Error("My first Sentry error!");
        },
      );
    }

    // Your existing routes and logic here...
    return new Response("...");
  },
};

To verify that Sentry catches your logs, add some log statements to your application:

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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",
});

Application Metrics are enabled by default.

Send test metrics from your app to verify that metrics are arriving in Sentry:

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Sentry.metrics.count("checkout.failed", 1);
Sentry.metrics.gauge("queue.depth", 42);
Sentry.metrics.distribution("api_latency", 187, {
  unit: "millisecond",
});

Now, head over to your project on Sentry.io to view the collected data (it takes a couple of moments for the data to appear).

Need help locating the captured errors in your Sentry project?
  • Open the Issues page and select an error from the issues list to view the full details and context of this error. For more details, see the Issue Details documentation.
  • Open the Traces page and select a trace to reveal more information about each span, its duration, and any errors. For an interactive UI walkthrough, click here.
  • Open the Logs page and filter by service, environment, or search keywords to view log entries from your application. For an interactive UI walkthrough, click here.
  • Open the Application Metrics page to view and analyze your metrics. For more details, see this interactive walkthrough.

Server-side spans will display 0ms for their durations. In the Cloudflare Workers runtime, performance.now() and Date.now() only advance after I/O occurs. CPU-bound operations will show zero duration. This is a security measure Cloudflare implements to mitigate against timing attacks.

This is expected behavior in the Cloudflare Workers environment and affects all frameworks deployed to Cloudflare Workers, including Next.js, Astro, Remix, and others.

At this point, you should have integrated Sentry and should already be sending data to your Sentry project.

Now's a good time to customize your setup and look into more advanced topics. Our next recommended steps for you are:

Are you having problems setting up the SDK?
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Welcome to Sentry
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Installation Methods
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