turboweb-mcp-by-ikari

A single-binary MCP server that drives a Chrome / Arc / Brave / Edge / Firefox tab through a companion browser extension and (optionally) WebDriver BiDi — with a live on-page agent overlay so a human user can watch what the agent is doing in real time.

The MCP server speaks stdio to your editor (Claude Code, Cursor, Claude Desktop, etc.) and a WebSocket to the extension on 127.0.0.1:18321. When WebDriver BiDi is available the same tools work cross-browser without an extension at all.

What you get

• On-page agent overlay — Shadow-DOM-isolated badge + animated cursor (quadratic Bezier arc, ~470ms sin-eased) with a robot icon pinned to the pointer. Per-action ripple colours (orange click, blue type, green scroll, purple navigate, red error). Bounding-box highlight on the target. Real DOM action is gated on cursor arrival so the click happens at the cursor, not while it's still flying.
• Visualised read-only tools — find_text and extract_text sweep a glowing loupe across matches; get_interactive_map fires a scan-flash outline over every interactive element on the page.
• Failure feedback — on tool error the cursor turns red, shakes, fires a red ripple, and a toast with the error message.
• Idle fade — cursor + badge fade out after 45s of inactivity.
• Extension popup with a Connected-agents section (every editor driving the browser is listed by session label, with a robot icon and client-type chip), expandable activity rows with intent, params, result summary, and a filter input. A ⤢ Pop out button spawns a resizable chrome.windows.create window with the same UI.
• intent argument required on every tool — the model writes a one-sentence narration before each call, surfaced as a toast on the page and as the leading text of every activity row.
• Pluggable AI backend for question-grounding on tool results: prefers Anthropic Haiku when configured, falls back to Chrome's built-in Gemini Nano (zero-cost, on-device) when not. See TURBOWEB_AI_BACKEND.

Build

make build            # → bin/turboweb-mcp-by-ikari
make release          # cross-compile + extension zips (+ signed .xpi if creds set)
make test             # go tests + extension vitest suite
make watch            # rebuild extension/dist on every source change

Layout: bin/ holds the local dev binary; dist/ holds release archives (everything you'd upload with gh release create vX.Y.Z dist/*).

Release matrix:

Target	File
macOS arm64	dist/turboweb-mcp-by-ikari-darwin-arm64
Linux x86-64	dist/turboweb-mcp-by-ikari-linux-amd64
Windows x86-64	dist/turboweb-mcp-by-ikari-windows-amd64.exe
Windows arm64	dist/turboweb-mcp-by-ikari-windows-arm64.exe
Chrome extension	dist/turboweb-mcp-by-ikari-extension-chrome.zip
Firefox add-on	dist/turboweb-mcp-by-ikari-extension-firefox.zip
Firefox signed XPI	dist/turboweb-mcp-by-ikari-extension-firefox-VERSION.xpi (only when AMO creds are set — see below)
Firefox update feed	dist/firefox-updates.json (paired with the signed XPI — see auto-update below)

Firefox XPI signing

make release produces an AMO-signed .xpi (installable on stock Firefox) when both env vars are set:

export WEB_EXT_API_KEY=user:xxxx:yy
export WEB_EXT_API_SECRET=<hex>
make release                            # → dist/*.xpi (channel=unlisted)
WEB_EXT_CHANNEL=listed make release     # submit to AMO public listing

Credentials are issued at https://addons.mozilla.org/en-US/developers/addon/api/key/. Without them, make extension-xpi (and therefore make release) prints a skip notice and exits 0 — local builds still succeed, the unsigned firefox .zip is always produced.

Firefox auto-update

The signed manifest carries browser_specific_settings.gecko.update_url pointing at https://github.com/ikari-software/turboweb-mcp/releases/latest/download/firefox-updates.json. Firefox polls this JSON daily; when its version is newer than the installed XPI, Firefox downloads the linked .xpi and replaces the extension in place.

The release workflow:

make release                            # builds + signs + emits firefox-updates.json
git tag v$(make -s print-VERSION)       # or `git tag v1.3.0` manually
git push --tags
gh release create v1.3.0 dist/*         # uploads xpi + updates.json + binaries

Once the GitHub release is published, the releases/latest/download/ URL resolves to the newly uploaded firefox-updates.json, and every installed extension picks up the new version within ~24h. To force a check sooner: about:addons → gear → Check for updates.

Note: update_url is part of the signed manifest, so a one-time manual reinstall is required to migrate users from any pre-1.3.0 XPI (which has no update_url) onto the auto-update channel.

Install

./setup.sh

setup.sh runs make build, then generates per-browser launcher scripts (bin/launch-{chrome,arc,brave,edge}.sh) that open the browser with the extension preloaded. For a persistent install, load extension/dist/chrome via chrome://extensions → Developer mode → Load unpacked (or grab the release zip — same contents).

Wire it into your MCP host (e.g. ~/.claude.json):

{
  "mcpServers": {
    "turboweb": {
      "command": "/path/to/bin/turboweb-mcp-by-ikari",
      "env": {
        "ANTHROPIC_API_KEY": "${ANTHROPIC_API_KEY}",
        "GEMINI_API_KEY": "${GEMINI_API_KEY}"
      }
    }
  }
}

Note on env vars: MCP hosts launch the server in a minimal environment that often does not inherit your shell's variables. The env block above forwards the keys from your shell into the server process. Omit whichever keys you don't use.

Environment variables

Variable	Default	Effect
ANTHROPIC_API_KEY / CLAUDE_API_KEY	unset	Enable Claude Haiku for AI-grounded answers
GEMINI_API_KEY	unset	Enable Google Gemini Flash for AI-grounded answers
TURBOWEB_AI_BACKEND	auto	auto · haiku · gemini · local · none
MCP_CLIENT_LABEL	derived	Override the session label shown in the extension popup

AI backends

Tools that accept a question argument hand the raw result to a language model for a concise answer. Set at least one key and the server picks it up at startup:

• Claude Haiku (claude-haiku-4-5-20251001) via ANTHROPIC_API_KEY. Multimodal (handles describe's screenshot), 80k-char context.
• Google Gemini Flash (gemini-2.0-flash-lite) via GEMINI_API_KEY. Multimodal, 80k-char context. Great choice when you have a Gemini key but not an Anthropic one.
• Chrome's built-in Gemini Nano (self.LanguageModel) — free, on-device, no key needed. Only available in Chrome 138+ with the Prompt API flag enabled. Text-only, ~12k-char context. Used as a last resort in auto.

auto cascade: Haiku → Gemini → local Gemini Nano → raw data (silent, no banner). When a configured provider fails (bad key, quota) a brief banner appears; when nothing is configured the tools just return raw structured data. Nothing breaks either way.

Tool surface

Every tool also accepts a required intent argument — one short sentence describing what the agent is about to do.

Browser & page: connection_status, list_tabs, navigate, launch_browser, screenshot, turbo_snapshot, page_yaml, page_reload, print_to_pdf.

DOM: extract_text, find_text, inspect, query_elements, get_html, get_interactive_map, describe, dom_snapshot, get_accessibility_tree.

Interaction: click, type_text, scroll, cdp_click, cdp_type, cdp_key, cdp_scroll, set_input_files, intercept_file_chooser.

click vs cdp_click:

• click — synthetic DOM events from the content script. Fast, works on most pages. The synthetic click is untrusted (event.isTrusted === false) and the activation may not run handlers that gate on trust; when a likely-untrusted case is detected (e.g. <a href="javascript:...") the response carries a hint pointing at cdp_click.
• cdp_click / cdp_type / cdp_scroll — real browser input dispatched via BiDi/CDP. Trusted events, works through MUI portals, popovers, and isTrusted guards. Each accepts either a selector (resolved on the page side) or an explicit position; selector wins when both are given.
  • cdp_click(selector | x,y) — clicks the element's centre.
  • cdp_type(text, [selector]) — types into whatever is focused, or focuses selector first (verifies activeElement actually moved).
  • cdp_scroll(deltaX, deltaY, selector | x,y) — wheel events dispatched AT a point, bubbling up to the nearest scrollable ancestor — that's how you scroll inner dropdowns / virtualised lists that window.scrollBy can't reach.

File uploads come in two flavours:

• set_input_files — when you can target the <input type=file> (or its wrapping label) with a selector. Works on hidden / styled inputs; attaches via CDP DOM.setFileInputFiles and fires the change event as if a human picked. Paths are resolved on the MCP server host: ~ is expanded, relative paths are rejected, symlinks are realpath'd.
• intercept_file_chooser — when the input is dispatched-via-button, cross-frame, or lazy-mounted and you can't grab it directly. Arm with enable=true + files, click the visible upload control, the next native file picker is auto-fulfilled and the queue is then dropped (one-shot). Re-arm before each additional upload, or disarm with enable=false.

JS execution: execute_js, adapt_script, add_preload_script.

Debug: console (console_enable/get/clear/disable), network (network_enable/get/get_body/throttle/disable), cookies/storage (get_cookies, set_cookie, delete_cookies, get_storage), performance (get_performance, css_coverage_start/stop), device emulation (emulate_device), cdp_detach.

Custom tools (SQLite-backed, persistent): create_tool, list_custom_tools, run_tool, delete_tool. Custom tools wrap an execute_js body and an optional system prompt for the AI post-processor.

Layout

turboweb-mcp-by-ikari/
├── main.go, ws.go             # MCP stdio + extension WebSocket
├── session.go                  # per-process session label + initialize hook
├── bidi*.go, browser.go       # WebDriver BiDi cross-browser path
├── tools_*.go                 # MCP tool registrations (addTool injects `intent`)
├── haiku.go, local_ai.go      # Anthropic Haiku + Chrome Gemini Nano backends
├── resize.go                  # in-process JPEG resize for screenshots
├── daemon{,_unix,_windows}.go # daemon-relay mode for shared extensions
└── extension/                 # Chrome MV3 extension (vitest suite under __tests__/)
    ├── background.js          # WS bridge, overlay/AI dispatch, telemetry
    ├── content.js             # DOM tools + Shadow-DOM overlay (cursor, ripple, loupe, toast)
    ├── popup.{html,js}        # Connected-agents list, expandable activity log, pop-out window
    └── build.js               # Source → dist/{chrome,firefox} (supports --watch)

The Go binary runs in two modes:

• MCP stdio (default) — what your editor talks to.
• --ws-server — long-lived daemon that owns port 18321; subsequent MCP processes connect to it via /relay. Useful if you run multiple editors against a single browser. The daemon attaches each connected agent's label to outgoing commands so the extension popup can attribute every action.

Security notes

The WebSocket binds to localhost only and rejects non-localhost origins. That's the only auth boundary: any process that can open a localhost TCP socket on this user's machine can connect as a relay client and drive the browser. Don't run untrusted local code under the same user account while turboweb is running.

The agent's intent text is self-reported, surfaced verbatim in the popup and toast. It's clamped to 200 chars server-side, but treat it as the model's claim about what it's doing — verify destructive actions in the activity-row params, not just by reading the intent.

Full threat model in SECURITY.md. macOS release binaries are notarized with a Developer ID Application certificate — Gatekeeper accepts downloaded copies automatically on first run, no manual steps needed. For supply-chain assurance (proving the binary came from this repo's CI pipeline), release assets are also signed via Sigstore cosign; see SECURITY.md for cosign verify-blob instructions.

Licence & trademark

Source is Apache 2.0 (LICENSE) — fork it, embed it, ship it, re-host it.

The name TurboWeb MCP, the by ikari attribution, the icon set, and the on-page robot-cursor mark are reserved. If you ship a modified build, rename it. Full policy in TRADEMARK.md.

Architecture notes

This repo previously had a parallel TypeScript MCP server in src/ plus a small Go subprocess in native/ that the TS server spawned just for JPEG resize. Both were retired in favour of the single Go binary, which already had cross-browser BiDi support, the same tool surface, and a proper daemon-relay mode. See the Consolidate on Go commit for the rationale.

The project was renamed from chrome-turbo-mcp to turboweb-mcp-by-ikari once the BiDi path made it genuinely cross-browser.