Complete browser automation with Playwright. **ALWAYS use when user needs browser testing, E2E testing, screenshots, form testing, or responsive design validation.** Auto-detects dev servers, saves test scripts to working directory. Examples - "test this page", "take screenshots of responsive design", "test login flow", "check for broken links", "validate form submission".
Automates browser testing and end-to-end workflows using Playwright. Automatically detects running dev servers and writes reusable test scripts to `.web-tests/scripts/` for screenshots, form testing, and responsive design validation.
/plugin marketplace add marcioaltoe/claude-craftkit/plugin install ui-tests@claude-craftkitThis skill inherits all available tools. When active, it can use any tool Claude has access to.
lib/helpers.jspackage.jsonrun.jsIMPORTANT - Path Resolution:
This skill is installed globally but saves outputs to the user's working directory. Always pass CWD environment variable when executing commands to ensure outputs go to the correct location.
Common installation paths:
~/.claude/plugins/marketplaces/claude-craftkit/plugins/ui-tests/skills/web-tests~/.claude/skills/web-tests<project>/.claude/skills/web-testsGeneral-purpose browser automation skill. I'll write custom Playwright code for any automation task you request and execute it via the universal executor.
CRITICAL WORKFLOW - Follow these steps in order:
Auto-detect dev servers - For localhost testing, ALWAYS run server detection FIRST:
cd $SKILL_DIR && node -e "require('./lib/helpers').detectDevServers().then(servers => console.log(JSON.stringify(servers)))"
Write scripts to user's working directory - Save to .web-tests/scripts/test-*.js in user's repo
Use visible browser by default - Always use headless: false unless user specifically requests headless mode
Parameterize URLs - Always make URLs configurable via constant at top of script
.web-tests/scripts/test-*.js (in user's working directory)CWD=$(pwd) cd $SKILL_DIR && node run.js .web-tests/scripts/test-*.js.web-tests/screenshots/cd $SKILL_DIR
npm run setup
This installs Playwright and Chromium browser. Only needed once.
Step 1: Detect dev servers (for localhost testing)
cd $SKILL_DIR && node -e "require('./lib/helpers').detectDevServers().then(s => console.log(JSON.stringify(s)))"
Step 2: Write test script to user's .web-tests/scripts/ with URL parameter
// .web-tests/scripts/test-page.js
const { chromium } = require("playwright");
// Parameterized URL (detected or user-provided)
const TARGET_URL = "http://localhost:3001"; // <-- Auto-detected or from user
(async () => {
const browser = await chromium.launch({ headless: false });
const page = await browser.newPage();
await page.goto(TARGET_URL);
console.log("Page loaded:", await page.title());
await page.screenshot({
path: ".web-tests/screenshots/page.png",
fullPage: true,
});
console.log("📸 Screenshot saved to .web-tests/screenshots/page.png");
await browser.close();
})();
Step 3: Execute from skill directory with CWD
CWD=$(pwd) cd $SKILL_DIR && node run.js $(pwd)/.web-tests/scripts/test-page.js
// .web-tests/scripts/test-responsive.js
const { chromium } = require("playwright");
const helpers = require("$SKILL_DIR/lib/helpers"); // Path will be resolved
const TARGET_URL = "http://localhost:3001"; // Auto-detected
(async () => {
const browser = await chromium.launch({ headless: false, slowMo: 100 });
const page = await browser.newPage();
// Desktop test
await page.setViewportSize({ width: 1920, height: 1080 });
await page.goto(TARGET_URL);
console.log("Desktop - Title:", await page.title());
await helpers.takeScreenshot(page, "desktop"); // Saves to .web-tests/screenshots/
// Mobile test
await page.setViewportSize({ width: 375, height: 667 });
await helpers.takeScreenshot(page, "mobile");
await browser.close();
})();
// .web-tests/scripts/test-login.js
const { chromium } = require("playwright");
const TARGET_URL = "http://localhost:3001"; // Auto-detected
(async () => {
const browser = await chromium.launch({ headless: false });
const page = await browser.newPage();
await page.goto(`${TARGET_URL}/login`);
await page.fill('input[name="email"]', "test@example.com");
await page.fill('input[name="password"]', "password123");
await page.click('button[type="submit"]');
// Wait for redirect
await page.waitForURL("**/dashboard");
console.log("✅ Login successful, redirected to dashboard");
await browser.close();
})();
// .web-tests/scripts/test-form.js
const { chromium } = require("playwright");
const helpers = require("$SKILL_DIR/lib/helpers");
const TARGET_URL = "http://localhost:3001"; // Auto-detected
(async () => {
const browser = await chromium.launch({ headless: false, slowMo: 50 });
const page = await browser.newPage();
await page.goto(`${TARGET_URL}/contact`);
await page.fill('input[name="name"]', "John Doe");
await page.fill('input[name="email"]', "john@example.com");
await page.fill('textarea[name="message"]', "Test message");
await helpers.takeScreenshot(page, "form-filled");
await page.click('button[type="submit"]');
// Verify submission
await page.waitForSelector(".success-message");
console.log("✅ Form submitted successfully");
await helpers.takeScreenshot(page, "form-success");
await browser.close();
})();
// .web-tests/scripts/test-broken-links.js
const { chromium } = require("playwright");
const TARGET_URL = "http://localhost:3001";
(async () => {
const browser = await chromium.launch({ headless: false });
const page = await browser.newPage();
await page.goto(TARGET_URL);
const links = await page.locator('a[href^="http"]').all();
const results = { working: 0, broken: [] };
for (const link of links) {
const href = await link.getAttribute("href");
try {
const response = await page.request.head(href);
if (response.ok()) {
results.working++;
} else {
results.broken.push({ url: href, status: response.status() });
}
} catch (e) {
results.broken.push({ url: href, error: e.message });
}
}
console.log(`✅ Working links: ${results.working}`);
console.log(`❌ Broken links:`, results.broken);
await browser.close();
})();
// .web-tests/scripts/screenshot-with-error-handling.js
const { chromium } = require("playwright");
const helpers = require("$SKILL_DIR/lib/helpers");
const TARGET_URL = "http://localhost:3001";
(async () => {
const browser = await chromium.launch({ headless: false });
const page = await browser.newPage();
try {
await page.goto(TARGET_URL, {
waitUntil: "networkidle",
timeout: 10000,
});
await helpers.takeScreenshot(page, "page-success");
console.log("📸 Screenshot saved successfully");
} catch (error) {
console.error("❌ Error:", error.message);
await helpers.takeScreenshot(page, "page-error");
} finally {
await browser.close();
}
})();
// .web-tests/scripts/test-responsive-full.js
const { chromium } = require("playwright");
const helpers = require("$SKILL_DIR/lib/helpers");
const TARGET_URL = "http://localhost:3001"; // Auto-detected
(async () => {
const browser = await chromium.launch({ headless: false });
const page = await browser.newPage();
const viewports = [
{ name: "Desktop", width: 1920, height: 1080 },
{ name: "Tablet", width: 768, height: 1024 },
{ name: "Mobile", width: 375, height: 667 },
];
for (const viewport of viewports) {
console.log(
`Testing ${viewport.name} (${viewport.width}x${viewport.height})`
);
await page.setViewportSize({
width: viewport.width,
height: viewport.height,
});
await page.goto(TARGET_URL);
await page.waitForTimeout(1000);
await helpers.takeScreenshot(page, viewport.name.toLowerCase());
}
console.log("✅ All viewports tested");
await browser.close();
})();
For quick one-off tasks, you can execute code inline without creating files:
# Take a quick screenshot
cd $SKILL_DIR && CWD=$(pwd) node run.js "
const browser = await chromium.launch({ headless: false });
const page = await browser.newPage();
await page.goto('http://localhost:3001');
await helpers.takeScreenshot(page, 'quick-test');
console.log('Screenshot saved');
await browser.close();
"
When to use inline vs files:
Optional utility functions in lib/helpers.js:
const helpers = require("./lib/helpers");
// Detect running dev servers (CRITICAL - use this first!)
const servers = await helpers.detectDevServers();
console.log("Found servers:", servers);
// Safe click with retry
await helpers.safeClick(page, "button.submit", { retries: 3 });
// Safe type with clear
await helpers.safeType(page, "#username", "testuser");
// Take timestamped screenshot (auto-saves to .web-tests/screenshots/)
await helpers.takeScreenshot(page, "test-result");
// Handle cookie banners
await helpers.handleCookieBanner(page);
// Extract table data
const data = await helpers.extractTableData(page, "table.results");
See lib/helpers.js for full list.
When testing, the skill creates this structure in the user's working directory:
user-repo/
└── .web-tests/
├── scripts/ # Test scripts (reusable)
│ ├── test-login.js
│ ├── test-form.js
│ ├── test-responsive.js
│ └── test-broken-links.js
└── screenshots/ # Screenshots with timestamps
├── desktop-2025-10-23T12-30-45.png
├── mobile-2025-10-23T12-30-51.png
└── form-success-2025-10-23T12-31-05.png
detectDevServers() before writing test code for localhost testing.web-tests/scripts/, screenshots auto-save to .web-tests/screenshots/TARGET_URL constant at the top of every scriptheadless: false unless user explicitly asks for headless modeheadless: true when user specifically requests "headless" or "background" executionslowMo: 100 to make actions visible and easier to followwaitForURL, waitForSelector, waitForLoadState instead of fixed timeoutsconsole.log() to track progress and show what's happeninghelpers.takeScreenshot() automatically saves to .web-tests/screenshots/Playwright not installed:
cd $SKILL_DIR && npm run setup
Module not found:
Ensure running from skill directory via run.js wrapper with CWD set
Browser doesn't open:
Check headless: false and ensure display available
Element not found:
Add wait: await page.waitForSelector('.element', { timeout: 10000 })
Screenshots not in .web-tests/:
Make sure CWD environment variable is set when executing
User: "Test if the marketing page looks good"
Claude: I'll test the marketing page across multiple viewports. Let me first detect running servers...
[Runs: detectDevServers()]
[Output: Found server on port 3001]
I found your dev server running on http://localhost:3001
[Writes custom automation script to .web-tests/scripts/test-marketing.js with URL parameterized]
[Runs: CWD=$(pwd) cd $SKILL_DIR && node run.js .web-tests/scripts/test-marketing.js]
[Shows results with screenshots from .web-tests/screenshots/]
User: "Check if login redirects correctly"
Claude: I'll test the login flow. First, let me check for running servers...
[Runs: detectDevServers()]
[Output: Found servers on ports 3000 and 3001]
I found 2 dev servers. Which one should I test?
- http://localhost:3000
- http://localhost:3001
User: "Use 3001"
[Writes login automation to .web-tests/scripts/test-login.js]
[Runs: CWD=$(pwd) cd $SKILL_DIR && node run.js .web-tests/scripts/test-login.js]
[Reports: ✅ Login successful, redirected to /dashboard]
.web-tests/scripts/ for reusability.web-tests/screenshots/ with timestampsrun.jsThis skill should be used when the user asks to "create a slash command", "add a command", "write a custom command", "define command arguments", "use command frontmatter", "organize commands", "create command with file references", "interactive command", "use AskUserQuestion in command", or needs guidance on slash command structure, YAML frontmatter fields, dynamic arguments, bash execution in commands, user interaction patterns, or command development best practices for Claude Code.
This skill should be used when the user asks to "create an agent", "add an agent", "write a subagent", "agent frontmatter", "when to use description", "agent examples", "agent tools", "agent colors", "autonomous agent", or needs guidance on agent structure, system prompts, triggering conditions, or agent development best practices for Claude Code plugins.
This skill should be used when the user asks to "create a hook", "add a PreToolUse/PostToolUse/Stop hook", "validate tool use", "implement prompt-based hooks", "use ${CLAUDE_PLUGIN_ROOT}", "set up event-driven automation", "block dangerous commands", or mentions hook events (PreToolUse, PostToolUse, Stop, SubagentStop, SessionStart, SessionEnd, UserPromptSubmit, PreCompact, Notification). Provides comprehensive guidance for creating and implementing Claude Code plugin hooks with focus on advanced prompt-based hooks API.