Astro on Cloudflare

Learn how to instrument your Astro app on Cloudflare Pages and capture your first errors.

You need:

  • A Sentry account and project
  • Your application up and running
  • Astro 3.0.0 or above

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.

Install and add the Sentry integration using the astro CLI:

Copied
npx astro add @sentry/astro

Next, install Sentry's Cloudflare SDK using your favorite package manager:

Copied
npm install @sentry/cloudflare --save

Register the Sentry integration in your astro.config.mjs file:

Start by following Astro's Cloudflare deployment guide. Add the Sentry integration to your config, alongside the Cloudflare adapter.

astro.config.mjs
Copied
import { defineConfig } from "astro/config";
import cloudflare from "@astrojs/cloudflare";
import sentry from "@sentry/astro";

export default defineConfig({
  adapter: cloudflare(),
  integrations: [sentry()],
});

Create a sentry.client.config.(ts|js) file in the root of your project. In this file, import and initialize Sentry for the client:

sentry.client.config.(ts|js)
Copied
import * as Sentry from "@sentry/astro";

Sentry.init({
  dsn: "___PUBLIC_DSN___",

  // Adds request headers and IP for users, for more info visit:
  // https://docs.sentry.io/platforms/javascript/guides/astro/configuration/options/#sendDefaultPii
  sendDefaultPii: true,

    // ___PRODUCT_OPTION_START___ performance
    Sentry.browserTracingIntegration(),
    // ___PRODUCT_OPTION_END___ performance
    // ___PRODUCT_OPTION_START___ session-replay
    Sentry.replayIntegration(),
    // ___PRODUCT_OPTION_END___ session-replay
    // ___PRODUCT_OPTION_START___ user-feedback
    Sentry.feedbackIntegration({
      // Additional SDK configuration goes in here, for example:
      colorScheme: "system",
    }),
    // ___PRODUCT_OPTION_END___ user-feedback
  // ___PRODUCT_OPTION_START___ performance

  // Define how likely traces are sampled. Adjust this value in production,
  // or use tracesSampler for greater control.
  tracesSampleRate: 1.0,
  // ___PRODUCT_OPTION_END___ performance
  // ___PRODUCT_OPTION_START___ session-replay

  // This sets the sample rate to be 10%. You may want this to be 100% while
  // in development and sample at a lower rate in production
  replaysSessionSampleRate: 0.1,

  // If the entire session is not sampled, use the below sample rate to sample
  // sessions when an error occurs.
  replaysOnErrorSampleRate: 1.0,
  // ___PRODUCT_OPTION_END___ session-replay
  // ___PRODUCT_OPTION_START___ logs

  // Enable logs to be sent to Sentry
  enableLogs: true,
  // ___PRODUCT_OPTION_END___ logs
});

Create a _middleware.js file in your functions directory (Cloudflare Pages middleware). Create the directory in the root of your project if it doesn't already exist, then create the file and import and initialize the Sentry Cloudflare SDK:

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

export const onRequest = [
  // Make sure Sentry is the first middleware
  Sentry.sentryPagesPlugin((context) => ({
    dsn: "___PUBLIC_DSN___",

    // Adds request headers and IP for users, for more info visit:
    // https://docs.sentry.io/platforms/javascript/guides/astro/configuration/options/#sendDefaultPii
    sendDefaultPii: true,
    // ___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/configuration/options/#traces-sample-rate
    tracesSampleRate: 1.0,
    // ___PRODUCT_OPTION_END___ performance

    // Optionally capture action formData attributes with errors.
    // This requires `sendDefaultPii` set to true as well.
    captureActionFormDataKeys: {
      key_x: true,
      key_y: true,
    },
  })),
  // Add more middlewares here
];

Since the SDK needs access to the AsyncLocalStorage API, you need to set the nodejs_compat compatibility flag in your wrangler.(jsonc|toml) configuration file:

wrangler.jsonc
Copied
{
  "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:

Using an SDK version before 10.35.0?

In earlier versions, you need to manually extract CF_VERSION_METADATA.id and pass it as the release option:

Copied
Sentry.withSentry(
  (env) => ({
    dsn: "___PUBLIC_DSN___",
    release: env.CF_VERSION_METADATA?.id,
  }),
  // ...
);
wrangler.jsonc
Copied
{
  // ...
  "version_metadata": {
    "binding": "CF_VERSION_METADATA"
  }
}

To upload source maps for clear error stack traces, add your Sentry auth token, organization, and project slugs in the sentry options inside astro.config.mjs:

astro.config.mjs
Copied
import { defineConfig } from "astro/config";
import cloudflare from "@astrojs/cloudflare";
import sentry from "@sentry/astro";

export default defineConfig({
  adapter: cloudflare(),
  integrations: [
    sentry({
      org: "___ORG_SLUG___",
      project: "___PROJECT_SLUG___",
      // store your auth token in an environment variable
      authToken: process.env.SENTRY_AUTH_TOKEN,
    }),
  ],
});

To keep your auth token secure, set the SENTRY_AUTH_TOKEN environment variable in your build environment:

.env.sentry-build-plugin
Copied
SENTRY_AUTH_TOKEN=___ORG_AUTH_TOKEN___

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

To verify that Sentry captures errors and creates issues in your Sentry project, create a test page, for example, at src/pages/test.astro with two buttons:

test.astro
Copied
<script>
  const buttonOne = document.getElementById("one");
  const buttonTwo = document.getElementById("two");

  buttonOne.addEventListener("click", throwTestError);
  buttonTwo.addEventListener("click", throwApiError);

  function throwTestError() {
    throw new Error("Sentry Example Frontend Error");
  }

  async function throwApiError() {
    await fetch("/api/test-error");
  }
</script>

<button id="one" type="button">Throw a frontend error</button>
<button id="two" type="button">Throw an API error</button>

Then also create the route we're calling in our test page, like src/pages/api/test-error.(js|ts):

test-error.(js|ts)
Copied
export async function GET() {
  throw new Error("Sentry Example API Route Error");
}

Open the page in a browser and click the buttons to trigger a frontend error and an error in the API route.

To test tracing, create a custom span to measure the time it takes for the API request to complete:

test.astro
Copied
<script>
  import * as Sentry from "@sentry/astro";

  const button = document.getElementById("one");

  button.addEventListener("click", throwApiError);

  async function throwApiError() {
    await Sentry.startSpan(
      {
        name: "Example Frontend Span",
        op: "test",
      },
      async () => {
        await fetch("/api/test-error");
      },
    );
  }
</script>

<button id="one" type="button">Throw an API error with a trace</button>

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?
  1. 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 this interactive walkthrough.
  2. 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.
  3. 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.

At this point, you should have integrated Sentry into your Astro application 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?
Previous
Frameworks on Cloudflare
Next
Hono on Cloudflare
Was this helpful?
Help improve this content
Our documentation is open source and available on GitHub. Your contributions are welcome, whether fixing a typo (drat!) or suggesting an update ("yeah, this would be better").