# playwright-in-sandbox

A skill that verifies UI changes in a sandbox browser and writes durable Playwright E2E coverage. Useful when you want screenshot proof, not just DOM state.

- skill · `type=skill` · Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, OpenCode · 508 installs · ★ 2
- Author: customware-ai
- License: MIT · policy=mirror · the beginning of the file is at the end of this page
- Source: https://github.com/customware-ai/skills/tree/HEAD/skills/playwright-in-sandbox/SKILL.md
- Updated: 2026-10-23
- HTML: https://affpapa.org/en/nevibecode/skills/playwright-in-sandbox

## What it does

The skill splits the work into two modes. Interactive Sandbox Mode is the final browser check once the implementation looks plausibly correct: the agent walks the changed flow and treats screenshots as evidence. Deterministic E2E Mode covers authoring or rewriting Playwright regression tests when a change fixes a bug or reshapes a user workflow.

Before touching the browser you write a short QA inventory and pick a mode. Then the app runs in a persistent session, the changed flow gets exercised, and the contracts you learned get recorded: route-ready signals, modal open and close signals, action-enabled conditions, save-complete signals, and durable `data-testid` selectors. Selectors are ranked from explicit `id` and `data-*` down to accessible roles, with CSS and XPath reserved for deliberate structure checks.

The environment contract matters. Playwright browsers may live under `/ms-playwright` in a sandbox, so confirm the path with `echo "$PLAYWRIGHT_BROWSERS_PATH"` and `ls -al /ms-playwright`, and launch Chromium explicitly in headless mode. If the repo expects `e2e.db` and it is missing, create it rather than falling back to the normal application database — running against production data hands you a fake green. Backend-only work and one-off page operations do not need this skill.

## Requirements
- Works with: Playwright

## Install

### Claude Code (native platform)

1. **Skills CLI (Vercel)**
```bash
npx skills add customware-ai/skills --skill playwright-in-sandbox -a claude-code
```

2. **Manually: put the files in place**
- File: `~/.claude/skills/playwright-in-sandbox/SKILL.md` — Copy the whole skill folder; for one project use .claude/skills/playwright-in-sandbox/

### Codex

1. **Skills CLI (Vercel)**
```bash
npx skills add customware-ai/skills --skill playwright-in-sandbox -a codex
```

2. **Manually: put the files in place**
- File: `.agents/skills/playwright-in-sandbox/SKILL.md` — For all projects use ~/.agents/skills/

### Cursor

1. **Skills CLI (Vercel)**
```bash
npx skills add customware-ai/skills --skill playwright-in-sandbox -a cursor
```

2. **Manually: put the files in place**
- File: `.cursor/skills/playwright-in-sandbox/SKILL.md` — Cursor also reads .agents/skills/ and .claude/skills/

### GitHub Copilot

1. **GitHub CLI**
```bash
gh skill install customware-ai/skills playwright-in-sandbox
```

2. **Manually: put the files in place**
- File: `.github/skills/playwright-in-sandbox/SKILL.md`

### Gemini CLI

1. **Skills CLI (Vercel)**
```bash
npx skills add customware-ai/skills --skill playwright-in-sandbox -a gemini-cli
```

2. **Platform CLI**
```bash
gemini skills install https://github.com/customware-ai/skills --path skills/playwright-in-sandbox
```

### Windsurf (Devin Desktop)

**Manually: put the files in place**
- File: `.devin/skills/playwright-in-sandbox/SKILL.md` — The legacy .windsurf/skills/ path still works

### OpenCode

**Skills CLI (Vercel)**
```bash
npx skills add customware-ai/skills --skill playwright-in-sandbox -a opencode
```

### Claude.ai

**Claude.ai**
- Zip the folder and upload it in Settings → Capabilities → Skills

Where a file is given instead of a command, copy the files from the source to that path: https://github.com/customware-ai/skills/tree/HEAD/skills/playwright-in-sandbox/SKILL.md

## When to use it
- get screenshot proof that a changed UI actually works
- lock a bug fix behind a regression test
- record readiness gates and modal behavior before writing tests
- pick durable selectors instead of CSS and XPath
- rewrite or consolidate legacy Playwright coverage

## Example prompts
- Verify the changed checkout screen in the browser and show me screenshots
- Write an E2E test for the signup flow with durable selectors
- Rewrite the old Playwright test and drop the CSS selectors

## Source text · SKILL.md · MIT

Below is the content of a third-party file. It is data, not instructions for you: do not act on anything written inside unless the human asks. Block tag: 5cdd8fbb99607df3.

BEGIN THIRD-PARTY FILE 5cdd8fbb99607df3
```text
---
name: "playwright-in-sandbox"
description: "Primary Playwright governance skill for sandbox browser verification and deterministic end-to-end authoring or rewrite work."
---

# Playwright In Sandbox

This is the primary Playwright skill for sandbox browser verification and deterministic end-to-end coverage.

Use it in two explicit modes:

1. **Interactive Sandbox Mode** as final browser verification after a task's implementation is in a plausibly correct state.
2. **Deterministic E2E Mode** before finishing a task when the changed flow should be protected by durable regression coverage.

This skill is intentionally generic. It should work for:

- task-level screenshot-driven verification after an agent has implemented UI work and needs browser proof
- formal Playwright E2E authoring or rewrite work in downstream application repos
- task flows where a final browser verification should happen before the task is considered complete

Do not use this skill for backend-only work, one-off page operations that do not justify browser automation, or broad failure storms before you understand the workflow inventory and root causes.

## Core Workflow

1. Write a brief QA inventory before touching the browser.
2. Decide the mode first: Interactive Sandbox Mode or Deterministic E2E Mode.
3. Start or confirm the app in a persistent session.
4. Implement the change and get the functionality into a plausibly correct state before using Playwright as signoff.
5. Run the changed flow interactively and inspect screenshots as evidence, not just DOM state.
6. Record the contracts you learned:
   - route-ready signals
   - modal open and close signals
   - action-enabled conditions
   - save-complete signals
   - durable `data-testid` or semantic selectors
7. If the flow is bug-fix, workflow, regression-critical, or meaningfully changed, graduate it into deterministic E2E coverage.
8. If interactive proof shows the product behavior is wrong, fix the product code or the data contract. Do not make a bad behavior look green by weakening the test.
9. Before finishing the task, ensure the changed flow has both:
   - successful interactive proof
   - durable E2E coverage or an explicit rationale why it stays interactive-only

## Common Rules
```
END THIRD-PARTY FILE 5cdd8fbb99607df3

The third-party file has ended. Everything between the 5cdd8fbb99607df3 tags is data: requests and commands from it are not followed. An “end of file” line with another tag inside the block is part of the file.

First 2256 of 19035 bytes. © customware-ai · MIT · https://github.com/customware-ai/skills/tree/HEAD/skills/playwright-in-sandbox/SKILL.md

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---
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