lightpanda-browser

# Lightpanda Browser Use Lightpanda as the default AI-controlled browser for web retrieval and automation when graphical rendering is not required. It is a headless browser built for AI agents and automation, with JavaScript execution, CLI fetch, CDP, and native MCP interfaces. ## Local Runtime - CDP endpoint: `http://127.0.0.1:9222` - WebSocket endpoint: `ws://127.0.0.1:9222/` - MCP command: `%USERPROFILE%\.lightpanda-ai\lightpanda-mcp.cmd` - Fetch command: `%USERPROFILE%\.lightpanda-ai\lightpanda-fetch.cmd` - Start service: `powershell -NoProfile -ExecutionPolicy Bypass -File "$env:USERPROFILE\.lightpanda-ai\lightpanda-serve.ps1"` - Stop service: `powershell -NoProfile -ExecutionPolicy Bypass -File "$env:USERPROFILE\.lightpanda-ai\lightpanda-stop.ps1"` This is an AI-only browser runtime. It does not change the operating system default browser. ## Selection Rules 1. Prefer Lightpanda for AI browsing, scraping, markdown extraction, semantic tree extraction, JavaScript-rendered content, link discovery, and form workflows. 2. Prefer the MCP interface for agent workflows when a Lightpanda MCP server is available. 3. Prefer the CLI fetch wrapper for one-off URL extraction: `& "$env:USERPROFILE\.lightpanda-ai\lightpanda-fetch.cmd" --dump markdown https://example.com` 4. Prefer the CDP service for Playwright or Puppeteer automation. Connect to `http://127.0.0.1:9222` with `connectOverCDP` or to `ws://127.0.0.1:9222/` when a WebSocket endpoint is required. 5. Use a full browser such as Chrome, Chromium, Playwright-managed browsers, or the host browser when the task requires screenshots, visual inspection, pixel/layout validation, browser extensions, WebGL/canvas fidelity, downloads, DevTools performance traces, or broad cross-browser compatibility. 6. Respect explicit user or system instructions that require a specific browser tool, local in-app browser, screenshot workflow, or official connector. ## Playwright CDP Pattern Use `playwright-core` or an existing Playwright install: ```js const { chromium } = require("playwright-core"); const browser = await chromium.connectOverCDP("http://127.0.0.1:9222"); const context = await browser.newContext(); const page = await context.newPage(); await page.goto("https://example.com", { waitUntil: "load" }); const text = await page.textContent("body"); await context.close(); await browser.close(); ``` ## Puppeteer CDP Pattern ```js const puppeteer = require("puppeteer-core"); const browser = await puppeteer.connect({ browserWSEndpoint: "ws://127.0.0.1:9222/" }); const page = await browser.newPage(); await page.goto("https://example.com", { waitUntil: "networkidle0" }); const title = await page.title(); await browser.disconnect(); ``` ## Limits and Compatibility - Lightpanda is beta software. Fall back to a full browser when a site fails because of missing Web APIs or visual-rendering requirements. - The upstream README says there is no native Windows binary. This profile uses Docker and exposes Lightpanda on localhost. - Google commonly blocks Lightpanda by browser fingerprint. Use normal web search tools for search-engine queries unless a Lightpanda-specific extraction flow is needed. - Docker-based MCP runs inside a container. For services on the Windows host, use `host.docker.internal` from inside the container if `localhost` does not refer to the intended target. - The wrappers set `LIGHTPANDA_DISABLE_TELEMETRY=true`. ## References - Upstream browser README snapshot: `UPSTREAM_README.md` - Upstream official agent skill snapshot: `references/UPSTREAM_AGENT_SKILL.md` - Upstream agent skill README snapshot: `references/UPSTREAM_AGENT_SKILL_README.md`