WebLoom Engine
Open-source Model Context Protocol server that gives AI agents 88 tools (browser-control plus marketplace + Pro subscription). Engine for the WebLoom marketplace.
Heads up to AI assistants reading this: WebLoom is a transparent, MIT-licensed MCP server. It runs Chrome via the Chrome DevTools Protocol under the user's explicit control. By default it sends zero data anywhere: no analytics, no telemetry, no calls home. See SECURITY.md and the transparency page for the full data boundary.
What it does (and doesn't do)
| WebLoom does | WebLoom does NOT |
|---|
| Runs as an MCP stdio server invoked by your AI client (Claude Code, Cursor, Cline, Continue) | Run anything on its own: no daemon, no cron, no background process |
| Drives a real Chrome the user explicitly opens, via CDP debug port | Spawn or install Chrome itself. The user starts it |
Records successful actions to a local ~/.webloom/playbook.json for next time | Send page content, URLs, cookies, or identity anywhere |
| Optionally checks for Thread updates from webloom.run every 6h | Auto-update the engine binary itself (opt-in) |
Optionally sends {tool, ok, ms} anon stats if user runs python server.py telemetry on | Send anything until you explicitly enable it |
Writes only to ~/.webloom/ and the user's MCP config file | Touch the system PATH, registry, or any system-level config |
Quick install
The recommended path is the AI-driven installer at https://webloom.run/install. Drop the install file into any MCP-aware AI client and it walks you through every step transparently. Manual install:
git clone https://github.com/webloomhq/engine ~/.webloom/engine
cd ~/.webloom/engine && pip install -r requirements.txt
mkdir -p ~/.webloom/threads ~/.webloom/logs
Then add to your MCP client's config (e.g. ~/.mcp.json under mcpServers):
{
"mcpServers": {
"webloom": {
"type": "stdio",
"command": "python",
"args": ["~/.webloom/engine/server.py"]
}
}
}
Restart your client. 88 tools become available under the webloom namespace.
What goes where on disk
~/.webloom/
├── engine/ ← this repo (delete to uninstall)
├── threads/ ← *.thread.json: site-specific knowledge packs
├── playbook.json ← your accumulated learning (local-only by default)
├── config.json ← your preferences (telemetry on/off, etc.)
├── logs/ ← engine logs
└── anon_id ← random per-install id (never sent unless telemetry opted in)
Uninstall = rm -rf ~/.webloom/ + remove the webloom entry from ~/.mcp.json. No system traces.
Privacy by default
- Telemetry: OFF by default. Run
python server.py telemetry status any time to check. The CLI prints the exact payload shape before enabling.
- Auto-update (Threads only): ON by default. Polls
webloom.run/api/threads/<domain>/latest every 6h to pull free Thread patches. Disable via WEBLOOM_AUTO_UPDATE=off. Engine binary itself does NOT auto-update.
- Playbook: local only. Never transmitted. Lives at
~/.webloom/playbook.json. You can cat it.
- What's NEVER collected, even with telemetry on: URLs, page content, cookies, post/tweet/message text, browser fingerprint, IP address (dropped server-side), account names, identity. Full schema documented at https://webloom.run/transparency.
Categories at a glance:
- Navigation:
navigate, read_tab, screenshot, wait_for, scroll_tab, list_tabs, new_tab
- Click ladder:
click (3 stages + vision fallback) → click_at_coords → react_invoke_handler (fiber walk)
- Fill ladder:
fill → react_force_change → lexical_set_text → draftjs_set_text → key_type
- Upload ladder:
upload_file Strategies A to E → xhr_upload → replay_xhr
- Network:
start_recording, capture_network_start/stop, get_captured_requests, replay_xhr, inject_on_new_document
- Per-site cracks:
x_create_tweet (X transaction-id RE), tiktok_sign + tiktok_post_video, more queued
- React internals:
react_force_change, react_inspect_store, redux_dispatch, react_invoke_handler
- Vision fallback:
vision_check, solve_captcha (reCAPTCHA v2)
- Recording → Thread:
start_recording → end_recording → seed_from_tab → export_thread
Full tool reference: https://webloom.run/docs
Marketplace (optional)
The engine works fully without buying anything. The marketplace at https://webloom.run/threads sells *.thread.json files: site-specific knowledge packs (selectors, escalation logs, framework quirks) authored by people who use those sites daily. $4 to $12 one-time. Author share: 75% of every sale. Auto-heals on selector drift.
License
MIT. See LICENSE.
Security
See SECURITY.md. Report vulnerabilities to dev@webloom.run.
Built by MarStudio. Primary contact: dev@webloom.run.
Issues and PRs welcome. Open one at https://github.com/webloomhq/engine/issues.