Chrome extension

Instrument any website for ClickStack session replay and RUM using the HyperDX Chrome extension

TL;DR

This guide shows how to inject the ClickStack Browser SDK into any website using the HyperDX Chrome extension. No changes to the target application’s source code are required — configure the extension once, browse the site, and view session replays in ClickStack.

Time required: 10-15 minutes

Overview

The HyperDX Chrome extension injects the @hyperdx/browser SDK into pages you visit. It is useful when you want to debug session replay, RUM, or trace propagation on a site without modifying its codebase — for example, a third-party application, a production build, or a local dev server with strict Content Security Policy (CSP).

The SDK is bundled inside the extension (~480 KB), so pages do not need to load scripts from a CDN at runtime. The extension tries external chrome-extension:// script injection first and falls back to inline injection when CSP blocks extension-origin scripts.

Unlike the Session Replay Demo, which instruments a demo application you control, this approach works on any URL you open in Chrome. You generate session data by interacting with the site as a normal user.

For background on session replay and how it fits into ClickStack, see the Session Replay feature page.

Prerequisites

• Google Chrome or a Chromium-based browser (Edge, Brave, etc.)
• Docker installed, if running ClickStack locally
• Ports 4317, 4318, and 8080 available (for local ClickStack)

Running the demo

1. Clone the extension repository

   git clone https://github.com/kyreddie/hyperdx-chrome-extension
   cd hyperdx-chrome-extension
   
2. Install the extension

   1. Open Chrome and go to chrome://extensions.
   2. Enable Developer mode (top right).
   3. Click Load unpacked.
   4. Select the hyperdx-chrome-extension directory you cloned.

   The extension appears in your toolbar as HyperDX Browser Extension.

3. Start ClickStack

   If you already have a ClickStack or HyperDX ingestion endpoint, skip to Configure the extension.

   For a local ClickStack stack, start the OpenTelemetry collector:

   docker run \
     -p 8080:8080 \
     -p 4317:4317 \
     -p 4318:4318 \
     clickhouse/clickstack-otel-collector:latest
   

   Open HyperDX at http://localhost:8080 to confirm the UI is running.

   For a full local deployment with ClickHouse and HyperDX UI, see Getting started with ClickStack.

4. Get your API key

   For local ClickStack, an API key may not be required — leave the field empty in the extension when sending telemetry to a self-hosted collector on http://localhost:4318.

   For ClickStack Cloud or HyperDX Cloud ingestion, open HyperDX, go to Team Settings → API Keys, and copy your Ingestion API Key.

5. Configure the extension

   Click the HyperDX Browser Extension icon in the Chrome toolbar and fill in the settings:

   Field	Local ClickStack example	Notes
   Enable HyperDX Monitoring	On	Master toggle for injection
   Service Name	my-frontend-app	Required — identifies the service in ClickStack
   API Key	(empty)	Required for cloud ingestion; optional for some self-hosted setups
   Collector URL	http://localhost:4318	OTLP HTTP endpoint; cloud default is https://in-otel.hyperdx.io
   Environment	development	Optional — sets deployment.environment resource attribute
   Trace Propagation Targets	/api\.myapp\.domain/i, /localhost/i	Optional — comma-separated JavaScript regex patterns for trace header propagation
   Only inject on matching URLs	Off	Enable to limit which sites are instrumented
   Capture console logs	Off	Enable to forward browser console output
   Advanced network capture	Off	Enable for detailed network request capture

   Click Save Configuration, then reload any tabs you want to instrument.

   The configuration above shows a typical local setup: monitoring enabled, service name set, collector pointed at http://localhost:4318, and trace propagation limited to API and localhost URLs.

6. Browse a site and generate a session

   Open any website or local application in Chrome — for example, http://localhost:3000 for a frontend dev server.

   Interact with the page normally: click links, submit forms, trigger errors, and navigate between views. The extension injects the Browser SDK automatically on each page load when configuration is valid.

7. View your session replay

   Return to HyperDX at http://localhost:8080 and navigate to Client Sessions from the left sidebar.

   You should see your session listed with its duration and event count. Click the ▶️ button to replay it.

   Switch between Highlighted and All Events modes to adjust the level of detail on the timeline.

URL filtering

By default, the extension injects the SDK on every page you visit while monitoring is enabled. To restrict injection to specific sites, turn on Only inject on matching URLs and add one pattern per line (or comma-separated):

Pattern	Matches
http://homedepot.com/*	HTTP only on homedepot.com
*://homedepot.com/*	HTTP and HTTPS on homedepot.com
*://*.homedepot.com/*	Subdomains such as www.homedepot.com
https://localhost:3000/*	Local dev server on port 3000

Reload the tab after saving URL patterns.

Verify injection

Open DevTools on a monitored page (Console tab), reload the page, and look for:

[HyperDX Extension] Configuration valid, injecting HyperDX
[HyperDX Extension] Injected via extension scripts
[HyperDX Extension] HyperDX initialized

If extension-origin scripts are blocked by CSP, the extension logs a fallback message and retries with inline injection.

Troubleshooting

Sessions not appearing in HyperDX

1. Check the browser console for [HyperDX Extension] log messages or errors
2. Confirm Enable HyperDX Monitoring is on and Service Name is set
3. Verify ClickStack is running and the collector URL is correct (e.g. http://localhost:4318)
4. Adjust the time range in the Client Sessions view (try Last 15 minutes)
5. Hard refresh the browser: Cmd+Shift+R (Mac) or Ctrl+Shift+R (Windows/Linux)

chrome-extension://invalid/ errors

Reload the extension at chrome://extensions, then hard-refresh the tab. This happens when the extension was updated or reloaded while tabs were still open.

No injection on a site

1. Check that monitoring is enabled and a service name is configured
2. If Only inject on matching URLs is on, confirm the current page URL matches one of your patterns
3. Some sites block both extension-origin and inline script injection via CSP — injection may not be possible on those pages

HyperDX: Missing apiKey in console

Expected when the API key field is empty. Add an ingestion API key from HyperDX for cloud endpoints, or ignore if your self-hosted collector accepts unauthenticated local traffic.

Privacy

The extension injects observability code into pages you visit. Use it only on sites you are allowed to debug. Do not share API keys or commit them to version control.

Learn more

• Session Replay — feature overview, SDK options, and privacy controls
• Browser SDK Reference — full SDK options and advanced configuration
• Session Replay Demo — instrument a demo application from source code
• ClickStack Getting Started — deploy ClickStack and ingest your first data
• HyperDX Chrome extension on GitHub — source code and issue tracker