Lightpanda

Headless browser written from scratch in Zig, designed for AI agents. Local, fast (~9x
faster, ~16x less memory than headless Chrome), AGPL-3.0. Installed at /opt/lightpanda/lightpanda
(nightly build), integrated into Hermes via native MCP as mcp_lightpanda_* tools.

Tool selection (scraping ladder)

1. 批量快爬 / 纯 dump → Lightpanda (mcp_lightpanda_*)
2. 常规单页 / 需 CSS 解析 → Scrapling (load scrapling skill)
3. 反爬 / Cloudflare / 登录 → Scrapling StealthyFetcher or Hermes browser
   (Lightpanda has NO stealth — it will lose to Cloudflare)
4. 长任务批量 → Spider / cron

Key MCP tools (31 registered)

goto (navigate+load), markdown (page→markdown), html, links, extract (structured
data), evaluate (JS), click, fill, scroll, press, hover, waitForSelector,
getCookies, search, session_new/session_list (isolated sessions), tree
(semantic DOM). Workflow: goto → waitForSelector/waitForState → markdown/extract.

CLI fallback (if MCP not loaded)

# Dump page to markdown (⚠️ use --log-level info; --log-level error swallows the dump output)
/opt/lightpanda/lightpanda fetch --dump markdown --log-level info https://example.com

# CDP server for Puppeteer/Playwright: /opt/lightpanda/lightpanda serve --host 127.0.0.1 --port 9222
# MCP server standalone: /opt/lightpanda/lightpanda mcp  (stdio) | mcp --port 9223 (HTTP)

Pitfalls

• --log-level error hides dump output — looks like a failed fetch. Use --log-level info.
• No stealth/anti-bot — Cloudflare/managed-challenge sites will fail; switch to Scrapling/browser.
• CORS not implemented (upstream issue #2015) — some sites' requests blocked by the browser itself.
• Beta, may crash — retry or fall back; don't debug config first.
• MCP tools appear only after Hermes restart (no hot-reload for MCP servers).

Install / Hermes MCP integration record

Full install + config.yaml integration + pitfalls (hermes config set can't write arrays,
MCP SDK goes in Hermes' own venv at /opt/data/home/.local/share/uv/tools/hermes-agent/,
restart required) — see web-research skill → references/lightpanda-browser-evaluation.md.