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Sentinel

Your AI-Powered
Browser Testing Co-pilot

Tell Claude, Cursor, or Copilot to test your app and write a guide — automatically. Or record manually, track bugs and feature requests, analyze issues, and export visual docs. Free, privacy-first Chrome extension with 50+ MCP tools.

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50+ MCP Tools Chrome MV3 React 19 TypeScript 5.9 Unlimited Storage 100% Local Open Source

Everything you need for web QA — manual or AI-driven

Sentinel replaces scattered tools with one lightweight extension. Use it manually or connect your AI assistant via MCP with 50+ tools to fully automate testing and documentation.

Action Recording

Captures clicks, typing, scrolls, form submissions, and navigation automatically with intelligent noise reduction, smart selectors, and candidate fallbacks.

Session Playback

Replay recorded sessions at 0.5x to 4x speed with selector recovery and heuristic matching. Step-by-step mode pauses after each action with element highlighting.

Assertion Testing

Add assertions with configurable retry logic — visible, hidden, text-contains, text-equals, has-class, or exists. Get pass/fail test reports with flakiness detection.

Visual Guide Export

Turn recordings into polished HTML guides with embedded screenshots. Add custom sections, choose internal or client export profiles, and use the block-based renderer for full control.

Bug & Issue Tracking

Auto-capture console errors, network failures, and CSP violations. Analyze issues with duplicate detection, clustering, and severity levels. Export styled reports with full error context.

Feature Requests

Create feature requests tied to specific page elements. Inspect an element, describe the enhancement, set priority, and export — all with screenshots and DOM context.

Video Recording

Capture up to 5 minutes of video per clip as WebM. Download clips or attach them to your bug reports for clear reproduction.

AI Automation (MCP)

50+ MCP tools let Claude, Cursor, or Copilot navigate, record, query elements, capture screenshots, drag-and-drop, compare screenshots, and export guides — fully hands-free.

Manual Notes & Annotation

Add manual notes with tagging and project tracking. Use the PowerPoint-style editor to annotate screenshots with pens, shapes, arrows, and text. Double-click to edit, drag to move, and manage layers.

Workspaces & Assets

Organize testing by project with descriptions and repository links. View all aggregated screenshots, videos, and findings in a centralized Resource Gallery per workspace.

100% Local & Private

Sentinel makes zero network requests. No analytics, no telemetry, no external servers. Your sessions, screenshots, and reports never leave your machine unless you explicitly export them.

Four steps to better QA

No setup, no accounts, no configuration files. Install, open the side panel, and start recording.

1

Record

Click the record button and interact with your web app. Sentinel captures every action with smart selectors and screenshots.

2

Review

Browse your recorded steps in the side panel. Each step shows what happened, where, and when — with a screenshot.

3

Test

Add assertions, then play back the session. Sentinel simulates every action and evaluates your assertions, producing a test report.

4

Export

Generate a standalone HTML guide, an issue report, or download a video clip. Share with your team — no logins needed.

Built for teams who ship

Whether you're a solo developer or part of a QA team, Sentinel fits your workflow.

QA Teams

Regression Testing

Record critical user flows, add assertions, and run regression playback before every release. Export test reports as evidence that paths work.

Engineering

Onboarding & Documentation

Walk through your app once and export a visual step-by-step guide. New team members get screenshots and descriptions instead of outdated wikis.

Support

Bug Reproduction

Enable error tracking, reproduce the bug, and export an issue report with screenshots, console errors, and network failures attached.

Product

Client Handoff

Record a walkthrough of completed features and export an HTML guide. Clients see exactly what was built — no staging environment needed.

AI Developer

Autonomous Testing & Docs

Point your AI at a project folder and say "test the checkout flow and write a guide." Claude Code, Cursor, or Copilot navigate, query elements, drag-and-drop, compare screenshots, and export — hands-free via 50+ MCP tools.

Solo Dev

Self-Review Before Shipping

Run a quick AI investigation on your dev server to surface JS errors and network failures before opening a PR. Get a screenshot + error report in seconds, with issue clustering and duplicate detection.

Install Sentinel

Choose your preferred installation method.

Chrome Web Store

One-click install from the Chrome Web Store.
Automatic updates included.

Coming Soon

Build from Source

Clone the repo, build with npm, and load as an unpacked extension.

View on GitHub

Ready to put AI to work on your QA?

Read the full user guide to get started — from manual recording to AI-driven automation via MCP.

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Sentinel is free and open source. If it saves you time, consider sponsoring the project ♥