UABC — Universal AI Browser Controller

Let AI use your real browser — your logins, your 2FA, your tabs — with your permission for every site.

UABC is a Chrome extension plus a small program (uabc). It gives AI three ways into your own browser profile, all behind the same safety gate:

Status: alpha. Everything described here works and is covered by end-to-end tests. It is not yet on the Chrome Web Store; build it from source. See ROADMAP.md.

Why

• Real sessions. Playwright and Selenium start empty profiles, and since Chrome 136 remote debugging is refused on your default profile. UABC works inside your normal browser, so Gmail, dashboards and intranet apps are already signed in.

• Any AI, no lock-in. Bring your own key and pick any model, plug in any MCP client, or reach the browser from a cloud chat app.

• Safe to hand your real profile to. AI only sees tabs you share, needs your approval for every new website, never touches password or payment fields, and stops instantly with one click or Alt+Shift+K. Read SECURITY.md.

• Bangla and every other script. Text goes through Chrome's input pipeline (Input.insertText), so আমার সোনার বাংলা types correctly, even in rich editors. The assistant answers in the language you write in.

Related MCP server: Browser Controller

How it works

 side panel chat ──(your API key)──▶ OpenAI · Anthropic · Gemini · OpenRouter · Ollama …
        │
        │ port            Claude Code, Codex …                Claude.ai, ChatGPT …
        │                       │ MCP stdio                         │ MCP over HTTPS
        │                       ▼                                   ▼
        │                   uabc mcp ─IPC─▶ uabc host          uabc relay (optional)
        │                                      │ native              ▲ WebSocket,
        ▼                                      ▼ messaging           │ opened by the browser
 ┌──────────────────────────────────────────────────────────────────────┐
 │ extension service worker — one gate for every AI client:             │
 │ UABC tab group · per-site approval · sensitive fields · Stop · log    │
 └──────────────────────────────────────────────────────────────────────┘
                                   ▼
                          your shared tabs

There is no listening port on your computer: the browser starts uabc, and only processes of your own OS user can reach it. The relay is opt-in; the browser connects out to it. Details: docs/architecture.md.

Quick start (from source)

Requirements: Node ≥ 20, Chrome/Chromium/Edge/Brave 116+, and Rust ≥ 1.88 for the uabc program.

git clone https://github.com/EJOBS-IT/uabc && cd uabc
npm ci
npm run build:ext            # → extension/dist
cargo build --release        # → target/release/uabc

Load the extension: chrome://extensions → Developer mode → Load unpacked → extension/dist. (Branded Chrome 137+ ignores --load-extension.)

A. Chat with the built-in assistant

1. In UABC's settings (opened on install) paste an API key under Built-in AI assistant. UABC checks it and loads the provider's models. For Ollama or LM Studio, add an OpenAI-compatible endpoint such as http://localhost:11434/v1.

2. Press Alt+Shift+U (or Open the assistant in the toolbar popup), pick a model and ask, for example: "bbc.com/bangla খুলে প্রধান খবরটা সংক্ষেপে বলো".

3. Approve the site when asked. Each step the assistant takes is listed in the chat; Stop ends it.

More: docs/assistant.md.

B. Connect your AI tools (MCP)

./target/release/uabc install --dev        # register the bridge (--dev trusts the unpacked build)
./target/release/uabc config claude-code   # or: codex, antigravity, cursor, gemini, vscode, generic
# claude mcp add --scope user uabc -- "/path/to/uabc" mcp

Then ask your agent something like "Open https://news.ycombinator.com and summarise the top 5 stories." uabc status shows registrations and running browsers; uabc call tabs.list sends a raw command.

C. Use the browser from Claude.ai or ChatGPT

1. Run a relay behind HTTPS: uabc relay --listen 127.0.0.1:8787 plus Caddy, nginx or a tunnel (docs/relay.md).

2. In UABC's settings, Use this browser from Claude, ChatGPT and other AI apps: turn it on, enter the relay address and copy the connector URL.

3. Claude: add a custom connector with that URL. ChatGPT: turn on developer mode and add a connector with that URL and no authentication (click and type need a plan with full MCP write actions; see the guide).

The URL works like a password; New URL revokes it. New sites still need your approval in the browser.

Tools

The same eleven tools for the assistant, MCP clients and cloud apps:

Errors come back as tool results with a code and a recovery hint, for example STALE_REF: … Call browser_get_state to get fresh refs, so models can correct themselves.

Safety model in one minute

• Workspace. AI only sees tabs in the "UABC" tab group. Drag a tab in to share it, out to revoke.

• Per-site approval. The first visit to a website opens a prompt naming the AI client (UABC assistant (model), claude-code, claude-ai (remote) …): Deny, Allow this time (only that client) or Always allow. AI cannot reach the prompt. Redirects and back/forward are gated on where they land.

• No credentials. Password, one-time-code and card fields are hidden from AI and cannot be typed into.

• Kill switch. The toolbar Stop button, Alt+Shift+K, or Cancel on Chrome's "started debugging" bar pauses every client, local or remote.

• Your keys stay yours. API keys live in extension storage that web pages and content scripts cannot read, and go only to the provider they belong to.

• Transparency. Badge, coloured tab group, connected clients, every step in the assistant's chat, and a local activity log. Everything taken from a page reaches the model fenced as untrusted content.

• Locked-down browsers. Managed browsers that block the debugger can switch to Basic input mode.

How is this different?

As of October 2026 there are good alternatives: Claude in Chrome (Claude only), Google's chrome-devtools-mcp (debugging-oriented), Microsoft's Playwright extension, and community projects such as mcp-chrome. UABC's focus:

• vendor-neutral: any model with your own key, any MCP client, cloud apps;

• no listening port on your computer; the relay is optional and self-hostable;

• per-site consent and credential rules enforced inside the extension, for every kind of client alike;

• first-class non-Latin text input;

• a degraded mode for managed browsers, and enterprise controls on the roadmap.

Repository layout

host/                Rust: the uabc binary (native host, MCP server, relay, installer)
extension/src/
  background/        service worker: gate, commands, native + relay bridges
  content/           page snapshots and actions
  assistant/         built-in assistant: provider adapters, agent loop, settings
  shared/            tool catalog, tool runner and formatter shared with the MCP server
  ui/                popup, settings, side panel, approval prompt
e2e/                 end-to-end tests: real Chromium, real binaries, MCP SDK, fake model APIs
docs/                architecture, protocol, ADRs, guides

Development

npm run watch              # rebuild the extension on change (reload it in chrome://extensions)
cargo build                # debug binary; run `uabc install --dev` again if the path changed
npm run typecheck
npm run test:unit          # TypeScript unit tests (vitest)
cargo test                 # Rust unit + integration tests
npm run test:e2e           # needs: npm run build:ext && cargo build

Host logs are in ~/.uabc/logs/host.log (%LOCALAPPDATA%\uabc\logs on Windows); set UABC_LOG=debug for more. See CONTRIBUTING.md.

Documentation

• Architecture · Wire protocol

• Guides: built-in assistant · running a relay

• Decisions:

  • ADR-0001 Rust host

  • ADR-0002 Content scripts + CDP

  • ADR-0003 No-TCP IPC security

  • ADR-0004 Workspace & site grants

  • ADR-0005 Three front-ends, one gate

• Security & threat model · Privacy · Roadmap · Chrome Web Store guide · Contributing

License

Apache-2.0. The name and logo are not covered by the license; see TRADEMARKS.md. Built by the R&D division of eJobs IT, Bangladesh.