Vessel: Your Agent's Browser

Open source chromium-based browser for persistent web agents. Linux is the most mature install target today, and macOS release packaging is available from source.

Vessel gives external agent harnesses a real browser with durable state, MCP control, and a human-visible supervisory UI. It is built for long-running workflows where the agent drives and the human audits, intervenes, and redirects when needed.

• Built for agent harnesses such as Hermes Agent, OpenClaw, and other MCP clients
• Keeps browser state alive with named sessions, pinned tabs, editable/exportable bookmarks, annotated checkpoints, action undo, and structured page visibility
• Keeps humans in the loop with approvals, runtime controls, and a visible browser instead of a headless black box

Vessel is in active development and currently makes no security assurances. Use and deploy it with care.

https://github.com/user-attachments/assets/0a72b48a-873a-4eb0-b8f2-23e34d8472c4

Quick Start

Want the full agent toolkit from day one? Start a 7-Day Free Trial of Vessel Premium — $5.99/mo.

Fastest Install Today

Linux AppImage from GitHub Releases:

1. Download the latest Vessel-<version>-x64.AppImage
2. Mark it executable: chmod +x Vessel-*.AppImage
3. Launch it: ./Vessel-*.AppImage
4. Open Settings (Ctrl+,) and confirm the MCP endpoint shown there

Install via npm

npm install -g @quanta-intellect/vessel-browser
vessel-browser

Or run it directly without installing:

npx @quanta-intellect/vessel-browser

Source Install

curl -fsSL https://raw.githubusercontent.com/unmodeled-tyler/vessel-browser/main/scripts/install.sh | bash

Development From Source

Vessel development uses Node.js 22. If you use fnm, run fnm use from the repo root to pick up .node-version.

fnm use
npm install
npm run dev

If you want extra local AI tracing in development, create an optional src/main/telemetry/trace-logger.local.cjs file. Vessel will load it only in local dev builds, and packaged production builds ignore it.

Why Vessel?

Most browser automation stacks are either headless, stateless, or designed around a human as the primary operator. Vessel is built around the opposite model: the browser is the agent's operating surface, and the human stays in the loop through a visible interface with clear supervisory controls.

Vessel is built for persistent web agents that need a real browser, durable state, and a human-visible interface. The agent is the primary operator. The human follows along in the live browser UI, audits what the agent is doing, and steers when needed.

Today, Vessel provides the browser shell, page visibility, and supervisory surfaces needed to support that model. The long-term goal is not "a browser with AI features," but a browser runtime for autonomous agents with a clear supervisory experience for humans.

Features

• Agent-first browser model — Vessel is designed around an agent driving the browser while a human watches, intervenes, and redirects
• Human-visible browser UI — pages render like a normal browser so agent activity stays legible instead of disappearing into a headless run
• Command Bar (Ctrl+L) — a secondary operator surface for harness-driven workflows and future runtime commands
• Supervisor Sidebar (Ctrl+Shift+L) — live supervision across eight tabs: Supervisor, Bookmarks, Checkpoints, Chat, Skills, History, Changes, and Research
• Chat Assistant — built-in conversational AI in the sidebar Chat tab; supports Anthropic, OpenAI, Ollama, llama.cpp, Mistral, xAI, Google Gemini, OpenRouter, and any OpenAI-compatible endpoint; reads the current page automatically; has full access to the same browser tools as external agents; multi-turn session history; configure provider, model, and API key in Settings
• Skills (Premium) — reusable browser skills in the sidebar Skills tab; import, view, run, or delete skills the built-in agent can use for research, shopping, and site-specific workflows
• Research Desk (Beta) — a dedicated sidebar Research tab for structured research reports; start with a topic, complete an in-tab briefing, let Vessel draft research objectives, approve the plan, then dispatch browser sub-agents to collect source-backed claims and synthesize a markdown-exportable report. Starting the brief is free; plan approval, sub-agent execution, and report export require Vessel Premium.
• Dev Tools Panel (F12) — inspect console output, network requests, and MCP/agent activity in a resizable panel at the bottom of the window; export logs by category and date range as JSON
• Browser Basics For Long Runs — pinned tabs stay compact at the front of the tab strip and are protected from accidental close; tab groups can be color-coded and collapsed; audible tabs show audio indicators with mute controls; open additional browser windows with Ctrl+N; print the active page with Ctrl+P or save it directly as PDF with Ctrl+Shift+P
• Action Undo / Rollback — restore the browser to the session snapshot captured immediately before the last successful mutating agent action; available from the Supervisor tab and through the undo_last_action tool
• Agent-Meaningful Bookmarks — bookmarks carry structured context the agent can read and act on: intent (what the page is for), expectedContent (what to expect on the page), keyFields (important form fields), agentHints (arbitrary directives), and a stored pageSchema; humans can create and edit this metadata directly in the Bookmarks tab, and all fields are searchable
• Portable Bookmark Export — export browser-compatible Netscape HTML for import into Chrome, Firefox, Safari, Edge, Brave, and other browsers; optionally include Vessel notes/agent metadata, or export a full-fidelity Vessel JSON archive
• Page Schema Inference — Vessel automatically infers a typed schema for every page: pageType (article, product, form, search, checkout, login, dashboard), primaryEntity (structured fields for products and articles), formFields (with names, types, labels, selectors), and actionButtons (with inferred intents: submit, addToCart, login, etc.); schema is attached to every content extraction result
• Bookmarks for Agents — save pages into folders, attach one-line folder summaries, and search bookmarks over MCP instead of dumping the entire library
• Named Session Persistence — save cookies, localStorage, and current tab layout under a reusable name, then reload it after a restart
• Annotated Checkpoints — capture and restore short-lived browser recovery points with names and editable notes, so humans and agents can mark why a checkpoint matters before risky flows
• Page Highlights — agents can visually highlight text or elements on any page with labeled, color-coded markers that persist across navigation; highlight count and navigation controls appear in the sidebar; cleared explicitly or via tool call
• Agent Transcript Dock — floating transcript overlay anchored to the browser chrome; configurable display modes (off, summary, full) set in Settings; shows live agent thinking and status updates without occupying sidebar space
• Workflow Flow Tracking — agents can declare a named multi-step workflow at runtime using flow_start; progress is tracked step-by-step with flow_advance and visible in the sidebar throughout execution
• Structured Page Visibility Context — extraction can report in-viewport elements, obscured controls, active overlays, and dormant consent/modal UI
• Popup Recovery Tools — agents can explicitly dismiss common popups, newsletter gates, and consent walls instead of brute-forcing generic clicks
• Form Autofill Profiles — save reusable personal or work profiles in Settings and fill common contact, address, and organization fields on the current page; Vessel matches fields using labels, names, placeholders, and autocomplete hints
• Page Diff / "What Changed?" — Vessel remembers the last snapshot of a page and surfaces a Changed badge in the address bar when the title, headings, or main content differ on a later visit; expand it to see a compact summary of what changed since the last snapshot
• What Changed Timeline (Premium) — the sidebar Changes tab k