playwriter

playwriter browser start  # starts Chrome for Testing/Chromium with bundled Playwriter extension
playwriter session new  # creates stateful sandbox, outputs session id (e.g. 1)
playwriter -s 1 -e 'await page.goto("https://example.com")'
playwriter -s 1 -e 'console.log(await snapshot({ page }))'
playwriter -s 1 -e 'await page.locator("aria-ref=e5").click()'

# Browser management
playwriter browser start             # auto-finds Chrome for Testing or Chromium, with recording flags enabled
playwriter browser start /path/to/browser-binary

# Session management
playwriter session new              # creates stateful sandbox, outputs id (e.g. 1)
playwriter session list             # show sessions + state keys
playwriter session reset <id>       # fix connection issues

# Execute (always use -s)
playwriter -s 1 -e 'await page.goto("https://example.com")'
playwriter -s 1 -e 'await page.click("button")'
playwriter -s 1 -e 'console.log(await page.title())'

playwriter -s 1 -e 'state.myPage = await context.newPage(); await state.myPage.goto("https://example.com")'

playwriter -s 1 -e $'
const title = await page.title();
console.log({ title, url: page.url() });
'

playwriter -e "state.users = await page.$$eval('.user', els => els.map(e => e.textContent))"
playwriter -e "console.log(state.users)"

playwriter -e "state.requests = []; page.on('response', r => { if (r.url().includes('/api/')) state.requests.push(r.url()) })"
playwriter -e "await Promise.all([page.waitForResponse(r => r.url().includes('/api/')), page.click('button')])"
playwriter -e "console.log(state.requests)"

playwriter -e "state.cdp = await getCDPSession({ page }); state.dbg = createDebugger({ cdp: state.cdp }); await state.dbg.enable()"
playwriter -e "state.scripts = await state.dbg.listScripts({ search: 'app' }); console.log(state.scripts.map(s => s.url))"
playwriter -e "await state.dbg.setBreakpoint({ file: state.scripts[0].url, line: 42 })"

playwriter -e "state.cdp = await getCDPSession({ page }); state.editor = createEditor({ cdp: state.cdp }); await state.editor.enable()"
playwriter -e "await state.editor.edit({ url: 'https://example.com/app.js', oldString: 'const DEBUG = false', newString: 'const DEBUG = true' })"

playwriter -e "await screenshotWithAccessibilityLabels({ page })"

await screenshotWithAccessibilityLabels({ page })
// Returns screenshot + accessibility snapshot with aria-ref selectors
await page.locator('aria-ref=e5').click()

+---------------------+     +-------------------+     +-----------------+
|   BROWSER           |     |   LOCALHOST       |     |   MCP CLIENT    |
|                     |     |                   |     |                 |
|  +---------------+  |     | WebSocket Server  |     |  +-----------+  |
|  |   Extension   |<--------->  :19988         |     |  | AI Agent  |  |
|  +-------+-------+  | WS  |                   |     |  +-----------+  |
|          |          |     |  /extension       |     |        |        |
|    chrome.debugger  |     |       |           |     |        v        |
|          v          |     |       v           |     |  +-----------+  |
|  +---------------+  |     |  /cdp/:id <--------------> |  execute  |  |
|  | Tab 1 (green) |  |     +-------------------+  WS |  +-----------+  |
|  | Tab 2 (green) |  |                               |        |        |
|  | Tab 3 (gray)  |  |     Tab 3 not controlled      |  Playwright API |
+---------------------+     (no extension click)      +-----------------+

npx -y traforo -p 19988 -t my-machine -- npx -y playwriter serve --token <secret>

export PLAYWRITER_HOST=https://my-machine-tunnel.traforo.dev
export PLAYWRITER_TOKEN=<secret>
playwriter -s 1 -e 'await page.goto("https://example.com")'

import { chromium } from 'playwright-core'
import { startPlayWriterCDPRelayServer, getCdpUrl } from 'playwriter'

const server = await startPlayWriterCDPRelayServer()
const browser = await chromium.connectOverCDP(getCdpUrl())
const page = browser.contexts()[0].pages()[0]

await page.goto('https://example.com')
await page.screenshot({ path: 'screenshot.png' })
// Don't call browser.close() - it closes the user's Chrome
server.close()

npx -y playwriter serve --host 127.0.0.1

const browser = await chromium.connectOverCDP('http://127.0.0.1:19988')

playwriter logfile  # prints the log file path
# typically: ~/.playwriter/relay-server.log

jq -r '.direction + "\t" + (.message.method // "response")' ~/.playwriter/cdp.jsonl | uniq -c