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Case study

devtools2025

Repro-in-a-Box

Autonomous QA agent that finds bugs on your site, captures reproducible evidence (HAR files + screenshots), validates reproducibility, and integrates with Claude Desktop via MCP. 7 built-in detectors: JavaScript errors, network failures, broken assets, WCAG 2.1 accessibility, Core Web Vitals, mixed content, and broken links. 170 tests, 85% coverage.

Building the tools that build the tools

Field notes

Role

Creator

Read order

Evidence first, then constraint → build → proof. Use the chapter rail to jump sections; orbit to adjacent work from the bottom of the case study.

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Evidence

System surface

No public screenshot on file—generative preview stands in for the visual layer.

Signature viewpreview

Story arc

How this shipped

Building the tools that build the toolsThree beats: what pressed against the work, how the stack answered, and what changed once it was live.

I · Constraint

The brief

Reproducing bugs reliably is the hardest part of QA. Evidence gets lost, steps get forgotten, and AI assistants have no direct access to QA findings.

II · Build

The craft

Autonomous Playwright-based crawler with 7 parallel detectors. HAR capture freezes the exact network state of a bug. Reproducibility validation confirms the bug before filing. MCP server exposes findings directly to Claude Desktop for AI-powered triage.

III · Proof

What moved after launch

170 tests across 11 files at 85% coverage. MCP integration means Claude can query and reason about bugs directly. HAR replay via Playwright makes every bug reproducible on demand.

Signals

◆Signals & scale

0
Test Coverage
0
Bug Detectors
0
Tests
Claude MCP
Integration

Engine room

At a glance

0
Tests

Inventory

Stack & signals

Node.jsTypeScriptPlaywrightMCPClaudeQA Automation
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Tell me what you're building

If you need someone who can own UI, systems, and AI integration without losing the plot—I'm listening. Contract, advisory, or full-time: we'll find the right shape.

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