Document the page-reuse pattern for the Framer project tab so repeated checks do not spawn duplicate tabs, and explicitly ban bringToFront in this guide to avoid interrupting the active browser window during local debugging.
Installation
-
Install Extension from Chrome Web Store
-
Click extension icon on a tab → turns green when connected
-
Install the CLI and start automating the browser:
npm i -g playwriter playwriter -s 1 -e "await page.goto('https://example.com')" -
Add skill to your agent:
npx -y skills add remorses/playwriter
Quick Start
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 accessibilitySnapshot({ page }))"
playwriter -s 1 -e "await page.locator('aria-ref=e5').click()"
CLI Usage
Each session has isolated state. Browser tabs are shared across sessions.
# 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())"
Create your own page to avoid interference from other agents:
playwriter -s 1 -e "state.myPage = await context.newPage(); await state.myPage.goto('https://example.com')"
Multiline:
playwriter -s 1 -e $'
const title = await page.title();
console.log({ title, url: page.url() });
'
Examples
Variables in scope: page, context, state (persists between calls), require, and Node.js globals.
Persist data in state:
playwriter -e "state.users = await page.$$eval('.user', els => els.map(e => e.textContent))"
playwriter -e "console.log(state.users)"
Intercept network requests:
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)"
Set breakpoints and debug:
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 })"
Live edit page code:
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' })"
Screenshot with labels:
playwriter -e "await screenshotWithAccessibilityLabels({ page })"
MCP Setup
Using the CLI with the skill (step 4 above) is the recommended approach. For direct MCP server configuration, see MCP.md.
Visual Labels
Vimium-style labels for AI agents to identify elements:
await screenshotWithAccessibilityLabels({ page })
// Returns screenshot + accessibility snapshot with aria-ref selectors
await page.locator('aria-ref=e5').click()
Color-coded: yellow=links, orange=buttons, coral=inputs, pink=checkboxes, peach=sliders, salmon=menus, amber=tabs.
Comparison
vs Playwright MCP
| Playwright MCP | Playwriter | |
|---|---|---|
| Browser | Spawns new Chrome | Uses your Chrome |
| Extensions | None | Your existing ones |
| Login state | Fresh | Already logged in |
| Bot detection | Always detected | Can bypass (disconnect extension) |
| Collaboration | Separate window | Same browser as user |
vs BrowserMCP
| BrowserMCP | Playwriter | |
|---|---|---|
| Tools | 12+ dedicated tools | 1 execute tool |
| API | Limited actions | Full Playwright |
| Context usage | High (tool schemas) | Low |
| LLM knowledge | Must learn tools | Already knows Playwright |
vs Antigravity (Jetski)
| Jetski | Playwriter | |
|---|---|---|
| Tools | 17+ tools | 1 tool |
| Subagent | Spawns for each browser task | Direct execution |
| Latency | High (agent overhead) | Low |
vs Claude Browser Extension
| Claude Extension | Playwriter | |
|---|---|---|
| Agent support | Claude only | Any MCP client |
| Windows WSL | No | Yes |
| Context method | Screenshots (100KB+) | A11y snapshots (5-20KB) |
| Playwright API | No | Full |
| Debugger/breakpoints | No | Yes |
| Live code editing | No | Yes |
| Network interception | Limited | Full |
| Raw CDP access | No | Yes |
Architecture
+---------------------+ +-------------------+ +-----------------+
| 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) +-----------------+
Remote CLI
Run CLI from a different machine (devcontainer, VM, SSH) while Chrome runs on your host.
On host:
playwriter serve --token <secret>
From remote:
playwriter --host 192.168.1.10 --token <secret> session new
playwriter --host 192.168.1.10 --token <secret> -s 1 -e "await page.goto('https://example.com')"
Or with env vars:
export PLAYWRITER_HOST=192.168.1.10
export PLAYWRITER_TOKEN=<secret>
playwriter -s 1 -e "await page.goto('https://example.com')"
Security
- Local only: WebSocket server on
localhost:19988 - Origin validation: Only our extension IDs allowed (browsers can't spoof Origin)
- Explicit consent: Only tabs where you clicked the extension icon
- Visible automation: Chrome shows automation banner on controlled tabs
- No remote access: Malicious websites cannot connect
Playwright API
Connect programmatically (without CLI):
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()
Or connect to a running server:
npx -y playwriter serve --host 127.0.0.1
const browser = await chromium.connectOverCDP('http://127.0.0.1:19988')
Troubleshooting
View relay server logs to debug issues:
playwriter logfile # prints the log file path
# typically: ~/.playwriter/relay-server.log
The relay log contains extension, MCP and WebSocket server logs. A separate CDP JSONL log is also created alongside it (see playwriter logfile). Both are recreated on each server start.
Example: summarize CDP traffic counts by direction + method:
jq -r '.direction + "\t" + (.message.method // "response")' ~/.playwriter/cdp.jsonl | uniq -c
Known Issues
- If all pages return
about:blank, restart Chrome (Chrome bug inchrome.debuggerAPI) - Browser may switch to light mode on connect (Playwright issue)
