Show HN: Vessel Browser – Open-Source AI-Native Browser with Skills

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 clientsKeeps browser state alive with named sessions, pinned tabs, editable/exportable bookmarks, annotated checkpoints, action undo, and structured page visibilityKeeps 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.

vessel-browser-demo-1.mp4 #

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

Linux AppImage from GitHub Releases:

• Download the latest Vessel-<version>-x64.AppImage

• Mark it executable: chmod +x Vessel-*.AppImage

• Launch it: ./Vessel-*.AppImage

• Open Settings ( Ctrl+,

) and confirm the MCP endpoint shown there

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

Or run it directly without installing:

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

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.

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.

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 commandsSupervisor Sidebar(Ctrl+Shift+L

) — live supervision across eight tabs: Supervisor, Bookmarks, Checkpoints, Chat, Skills, History, Changes, and ResearchChat 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 SettingsSkills(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 workflowsResearch 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 JSONBrowser 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 withCtrl+N

; print the active page withCtrl+P

or save it directly as PDF withCtrl+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 theundo_last_action

toolAgent-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 storedpageSchema

; humans can create and edit this metadata directly in the Bookmarks tab, and all fields are searchablePortable 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 archivePage 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), andactionButtons

(with inferred intents: submit, addToCart, login, etc.); schema is attached to every content extraction resultBookmarks for Agents— save pages into folders, attach one-line folder summaries, and search bookmarks over MCP instead of dumping the entire libraryNamed 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 flowsPage 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 callAgent 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 spaceWorkflow Flow Tracking— agents can declare a named multi-step workflow at runtime usingflow_start

; progress is tracked step-by-step withflow_advance

and visible in the sidebar throughout executionStructured 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 clicksForm 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 hintsPage Diff / "What Changed?"— Vessel remembers the last snapshot of a page and surfaces aChanged

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 snapshotWhat Changed Timeline(Premium) — the sidebar Changes tab keeps a per-page history of recent change bursts, showing when each update was detected and a compact summary of what changedPer-Tab Ad Blocking Controls— tabs default to ad blocking on, but agents can selectively disable and re-enable blocking when a page misbehaves** Domain Policy**— allowlist or blocklist domains globally in Settings; agents cannot navigate to blocked domains** Agent Credential Vault**(Premium) — encrypted credential storage for agent-driven logins; credentials are filled directly into login forms via a "blind fill" pattern and are never sent to AI providers; user consent dialog before every use; TOTP 2FA support; domain-scoped access; append-only audit logScreenshot & Visual Analysis(Premium) — take a full-page screenshot and pass the image directly to the AI for visual layout analysis; useful when text extraction fails on heavy or canvas-rendered pagesObsidian Memory Hooks(Premium) — optional vault path for agent-written markdown notes, page captures, and research breadcrumbs** Runtime Health Checks**— startup warnings for MCP port conflicts, unreadable settings, and user-data write failures** Reader Mode**— extract article content into a clean, distraction-free view; toggle on and off from the address bar** Focus Mode**(Ctrl+Shift+F

) — hide all chrome, content fills the screenResizable Panels— drag the sidebar edge to resize; width persists across sessions** Minimal Dark Theme**— warm dark grays, restrained accent color, and no pure black/white

Most browsers treat automation as secondary and assume a human is the primary actor. Vessel is the opposite: it is the browser for the agent, with a visible interface that keeps the human in the loop.

That means the product should optimize for:

• persistent browser state across tasks and sessions
• clear visibility into what the agent is doing right now
• lightweight human intervention instead of constant manual driving
• a browser runtime that can serve long-lived agent systems such as Hermes Agent or OpenClaw-style harnesses

Layer	Technology
Engine	Chromium (Electron 40)
UI Framework	SolidJS
Language	TypeScript
Build	electron-vite + Vite
AI Control	External agent harnesses (Hermes Agent, OpenClaw, MCP clients) + built-in chat (Anthropic, OpenAI, Ollama, llama.cpp, and any OAI-compatible endpoint)
Content Extraction	@mozilla/readability

Main Process                              Renderer (SolidJS)
├── TabManager (WebContentsView[])        ├── TabBar, AddressBar
├── AgentRuntime (session + supervision)  ├── CommandBar (secondary surface)
├── MCP server for external agents        ├── AI Sidebar (Supervisor/Bookmarks/Checkpoints/Chat/Automate/History/Changes/Research)
├── AI providers (Anthropic + OAI-compat) ├── DevTools Panel (Console/Network/Activity)
├── Supervision, bookmarks, checkpoints   ├── Agent Transcript Dock
└── IPC Handlers ◄──contextBridge──► ──► └── Signal stores (tabs, ai, ui)
└── IPC Handlers ◄──contextBridge──► Preload API

Each browser tab is a separate WebContentsView

managed by the main process. The browser chrome (SolidJS) runs in its own view layered on top. All communication between renderer and main goes through typed IPC channels via contextBridge

.

The sidebar Skills tab renders skill forms entirely in the renderer and passes the rendered prompt to the built-in agent via the same query()

path used by the Chat tab — no additional IPC surface is needed. The Changes tab reads the current page's diff timeline through IPC and unlocks persisted history for Premium users. The Research tab has a dedicated IPC surface for its state machine: briefing is available to everyone, while objective approval, parallel browser sub-agents, report synthesis, and markdown export are Premium-gated during the beta.

The installer:

• clones or updates Vessel into ~/.local/share/vessel-browser

• installs dependencies and builds the app

• creates a vessel-browser

launcher in~/.local/bin

• creates a vessel-browser-launch

helper in~/.local/bin

• creates a vessel-browser-update

helper in~/.local/bin

• creates a vessel-browser-status

helper in~/.local/bin

• creates a desktop entry for Linux app launchers
• writes ~/.config/vessel/vessel-settings.json

with MCP port3100

• writes ~/.config/vessel/mcp-stdio-snippet.json

• writes ~/.config/vessel/mcp-http-snippet.json

• installs a vessel-browser-mcp

helper that can run as a stdio-to-HTTP proxy (--stdio

) or print config snippets - prints the exact recommended stdio MCP snippet to paste into your harness config

The packaged AppImage path:

• does not require a local Node/Electron toolchain
• uses the packaged Vessel app icon and metadata
• is the recommended path for early adopters who just want to run Vessel

Windows packaged releases:

• use the Vessel-<version>-x64-setup.exe

NSIS installer - can be installed over an existing Vessel install when upgrading

• preserve Vessel app data during the normal upgrade path

You do not need to uninstall Vessel before installing a newer Windows release. Uninstall first only if you are recovering from a broken install or intentionally removing local Vessel data.

After install:

vessel-browser
fnm use

npm install

ELECTRON_MIRROR="https://npmmirror.com/mirrors/electron/" npm install

npm run dev

npm run build

npm run smoke:test

npm run dist:dir

npm run dist

npm run dist:mac:dir

npm run dist:mac

npm run verify:mac:universal

npm run dist:mac:signed

Notes:

npm run dev

still launches the stock Electron binary, so Linux may continue showing the default Electron gear icon in development- packaged builds created with npm run dist

/npm run dist:dir

use the Vessel app icon npm run build:icon:mac

regeneratesresources/vessel-icon.icns

fromresources/vessel-icon.png

for macOS packagingnpm run dist:mac

andnpm run dist:mac:dir

build universal macOS artifacts by default, so the same app runs natively on Intel and Apple Silicon Macsnpm run dist:mac:x64

andnpm run dist:mac:arm64

are available when you need smaller architecture-specific test artifactsnpm run verify:mac:universal

useslipo

to confirm the packaged app executable and Electron framework include bothx86_64

andarm64

slicesnpm run dist:mac

,npm run dist:mac:dir

,npm run dist:mac:x64

, andnpm run dist:mac:arm64

intentionally disable auto-signing so local packaging works on any Mac without keychain setupnpm run dist:mac:signed

andnpm run dist:mac:dir:signed

build universal artifacts and use normalelectron-builder

signing discovery; if your login keychain has duplicate Apple certs, clean those up or use a dedicated keychain before running the signed path- signed builds are still not notarized by this repo out of the box, so Gatekeeper warnings remain until notarization is added for release publishing

• the tracked smoke test runs typecheck, build, the MCP stdio proxy regression check, and the Electron navigation regression harness
• for headless CI, run the smoke test under xvfb-run -a npm run smoke:test

Vessel is designed to act as the browser runtime that your external agent harness drives.

• Launch Vessel
• Open Settings ( Ctrl+,

) to confirm MCP status, copy the endpoint, or change the MCP port - Optional: set an Obsidian vault path, create autofill profiles, or adjust session preferences

• Start Hermes Agent or OpenClaw and point it at Vessel — the easiest way is vessel-browser-mcp --stdio

as the MCP command (auth is resolved automatically), or connect directly tohttp://127.0.0.1:<mcpPort>/mcp

with the bearer token from~/.config/vessel/mcp-auth.json

• Use the Supervisor panel in Vessel's sidebar to the agent, change approval mode, review pending approvals, checkpoint, undo the last mutating action, or restore the browser session while the harness runs
• Use the Bookmarks panel to organize saved pages into folders, edit agent-facing bookmark metadata, export bookmarks for other browsers, and expose saved pages back to the agent over MCP

Notes:

• Vessel exposes browser control to external agents through its local MCP server

• The default MCP port is 3100

• Hermes Agent and OpenClaw should treat Vessel as the persistent, human-visible browser rather than launching their own separate browser session

• Vessel supports a built-in Chat tab with configurable AI provider; open Settings ( Ctrl+,

) and enable Chat Assistant to set a provider and model - The sidebar Research tab is marked Beta; use it to turn a broad research topic into a brief, approve a multi-thread plan, run browser sub-agents, and export the final report as markdown. Briefing is free, while full execution and export require Premium. llama.cpp (Local)

is a first-class chat provider in Settings and targetshttp://localhost:8080/v1

by default; Vessel auto-fetches the active model fromllama-server

• For llama-server

, use--ctx-size 16384

minimum and32768

recommended for reliable Vessel agent loops; lower values often fail once prompt, tool schema, and tool history accumulate - Approval policy is controlled live from the sidebar Supervisor panel rather than a separate global settings screen

• Settings now show MCP runtime status, active endpoint, startup warnings, and allow changing the MCP port with an immediate server restart
• Settings also include reusable Form Autofill profiles for one-click filling of common contact and address forms on the active page
• The address bar can also show a Changed

badge when Vessel detects that a previously visited page has meaningfully changed since the last saved snapshot - Premium users can open the sidebar Changes tab for the full What Changed timeline for the active page

• The Bookmarks tab can export browser-compatible HTML, HTML with Vessel notes, or a full Vessel JSON archive with agent metadata intact
• Agents can selectively disable ad blocking for a problematic tab, reload, retry the flow, and turn blocking back on later
• Agents can persist authenticated state with named sessions, for example github-logged-in

, and reload that state in later runs - The intended control plane is an external harness driving Vessel through MCP

• If you set an Obsidian vault path in Settings, harnesses can write markdown notes directly into that vault via Vessel memory MCP tools

Vessel can talk directly to a local llama-server

through its OpenAI-compatible API.

Example:

llama-server -m /path/to/model.gguf --port 8080 --ctx-size 32768

Then in Vessel:

• Open Settings ( Ctrl+,

) - Enable Chat Assistant

• Choose llama.cpp (Local)

as the provider - Click refresh if needed; Vessel will auto-detect the active model from http://localhost:8080/v1

Notes:

--ctx-size 16384

is the minimum practical setting for Vessel agent loops--ctx-size 32768

is the recommended default for longer browsing sessions- Vessel will warn in Settings if it detects a llama-server

context size below the recommended floor, or if it cannot detect the ctx size from the running server

Initial memory tools:

vessel_memory_note_create

vessel_memory_append

vessel_memory_list

vessel_memory_search

vessel_memory_page_capture

vessel_memory_link_bookmark

Bookmark and folder tools exposed today include:

vessel_bookmark_list

vessel_bookmark_search

vessel_bookmark_open

vessel_bookmark_save

vessel_bookmark_remove

vessel_create_folder

vessel_folder_rename

vessel_folder_remove

Page interaction and recovery tools exposed today include:

vessel_extract_content

vessel_read_page

vessel_scroll

vessel_dismiss_popup

vessel_set_ad_blocking

vessel_wait_for

vessel_screenshot

(Premium) — capture the full page as an image for visual AI analysisundo_last_action

— restore the browser to the snapshot captured before the last successful mutating agent action

Page highlight tools:

vessel_highlight

— visually mark text or an element on the page with a labeled, color-coded overlay; persists until clearedvessel_clear_highlights

— remove all highlights from the current page

Workflow tracking tools:

vessel_flow_start

— begin a named multi-step workflow and declare its steps upfront; progress appears in the sidebar throughout executionvessel_flow_advance

— mark the current step complete and advance to the nextvessel_flow_status

— check current workflow progressvessel_flow_end

— clear the active workflow tracker

Data extraction tools (Premium):

vessel_extract_table

— extract a page table as structured JSON rows with column headers

Named session tools exposed today include:

vessel_save_session

vessel_load_session

vessel_list_sessions

vessel_delete_session

Session files are sensitive because they may contain login cookies and tokens. Vessel stores them under the app user-data directory with restrictive file permissions.

Agent Credential Vault tools (Premium):

vessel_vault_status

— check whether stored credentials exist for a domain (returns labels/usernames, never passwords)vessel_vault_login

— fill a login form using stored credentials (blind fill — credentials go directly into the page, never into the AI conversation)vessel_vault_totp

— generate and fill a TOTP 2FA code from a stored secret

Session performance tools (Premium):

vessel_metrics

— show per-tool call counts, average durations, error rates, and total session stats

Vault security model:

• Credentials are encrypted at rest using AES-256-GCM with a key protected by the OS keychain (Electron safeStorage)
• Credential values are never sent to AI providers — they flow only through the main process to the content script - Every credential use triggers a user consent dialog ("Allow Once" / "Allow for Session" / "Deny")
• All credential access is recorded in an append-only audit log
• Credentials are domain-scoped — they can only be used on matching domains
• Users manage credentials in Settings > Agent Credential Vault

Notable extraction modes include:

visible_only

— only currently visible, in-viewport, unobstructed interactive elements plus active overlaysresults_only

— likely primary search/result links onlyfull

/summary

/interactives_only

/forms_only

/text_only

The extraction output can distinguish:

• active blocking overlays
• dormant consent/modal UI present in the DOM but not active for the current session or region

Stdio proxy MCP config (recommended — resolves auth automatically):

{
  "mcpServers": {
    "vessel": {
      "command": "vessel-browser-mcp",
      "args": ["--stdio"]
    }
  }
}

The stdio proxy reads the bearer token from ~/.config/vessel/mcp-auth.json

at connection time, so no manual token management is needed. Vessel must already be running when your MCP client connects, and ~/.config/vessel/mcp-auth.json

must exist from install or first launch.

Generic HTTP MCP config (requires copying the token manually):

{
  "mcpServers": {
    "vessel": {
      "type": "http",
      "url": "http://127.0.0.1:3100/mcp",
      "headers": {
        "Authorization": "Bearer <token from ~/.config/vessel/mcp-auth.json>"
      }
    }
  }
}

Hermes Agent config.yaml

MCP config:

mcp_servers:
  vessel:
    url: "http://127.0.0.1:3100/mcp"
    headers:
      Authorization: "Bearer <token from ~/.config/vessel/mcp-auth.json>"
    timeout: 180
    connect_timeout: 30

The installer writes three snippets to:

~/.config/vessel/mcp-stdio-snippet.json

~/.config/vessel/mcp-http-snippet.json

~/.config/vessel/mcp-hermes-snippet.yaml

It also installs a helper command:

vessel-browser-mcp

Helper examples:

vessel-browser-mcp --stdio

vessel-browser-mcp

vessel-browser-mcp --format json

vessel-browser-mcp --format hermes

vessel-browser-mcp --format url

vessel-browser-mcp --format token

Source install update helpers:

vessel-browser-update --check

vessel-browser-update

Status helper:

vessel-browser-status

vessel-browser-status --json

Smart launch helper:

vessel-browser-launch

vessel-browser-launch --dry-run

vessel-browser-launch

prefers a healthy source install and falls back to the newest local AppImage when the source install is likely blocked by Electron sandbox permissions.

Shortcut	Action
Ctrl+L
AI Command Bar
Ctrl+Shift+L
Toggle AI Sidebar
Ctrl+Shift+F
Toggle Focus Mode
F12
Toggle Dev Tools Panel
Ctrl+N
New Window
Ctrl+T
New Tab
Ctrl+W
Close Tab
Ctrl+Shift+T
Reopen Closed Tab
Ctrl+Shift+N
New Private Window
Ctrl+F
Find in Page
Ctrl++ / Ctrl+=
Zoom In
Ctrl+-
Zoom Out
Ctrl+0
Reset Zoom
Ctrl+P
Print Active Page
Ctrl+Shift+P
Save Active Page as PDF
Ctrl+,
Settings

src/
├── main/                 # Electron main process
│   ├── ai/               # Agent tools, query flow, and AI provider implementations
│   ├── tabs/             # Tab + TabManager (WebContentsView)
│   ├── agent/            # Agent runtime, checkpoints, supervision, flow tracking
│   ├── content/          # Readability extraction, reader mode, screenshot, page snapshots/diff
│   ├── config/           # Settings persistence
│   ├── autofill/         # Autofill profile persistence and form-field matching
│   ├── ipc/              # IPC handler registry
│   ├── vault/            # Agent Credential Vault (encrypted storage, consent, audit)
│   ├── mcp/              # MCP server for external agent control
│   ├── devtools/         # CDP session management for Dev Tools panel
│   ├── highlights/       # Page highlight capture, injection, and persistence
│   ├── health/           # Runtime health monitoring (MCP, settings, ports)
│   ├── premium/          # Subscription management, feature gating, Stripe integration
│   ├── bookmarks/        # Bookmark and folder persistence
│   ├── history/          # Browse history
│   ├── memory/           # Obsidian vault hooks
│   ├── network/          # Ad blocking, URL safety, link validation, downloads
│   ├── sessions/         # Named session save/load/delete
│   ├── startup/          # App initialization, menu, shortcuts, renderer bootstrap
│   ├── telemetry/        # PostHog analytics (opt-in)
│   ├── tools/            # Tool definitions, input coercion, pruning
│   ├── window.ts         # Window layout manager
│   └── index.ts          # App entry point
├── preload/              # contextBridge scripts
│   ├── index.ts          # Chrome UI preload
│   └── content-script.ts # Web page preload (readability)
├── renderer/             # SolidJS browser UI
│   └── src/
│       ├── components/
│       │   ├── chrome/   # TitleBar, TabBar, AddressBar, AgentTranscriptDock
│       │   ├── ai/       # CommandBar, Sidebar (Supervisor/Bookmarks/Checkpoints/Chat/Automate/History/Changes/Research)
│       │   ├── devtools/ # DevTools panel (Console, Network, Activity)
│       │   └── shared/   # Settings panel
│       ├── stores/       # SolidJS signal stores (tabs, ai, ui, runtime, bookmarks, etc.)
│       ├── styles/       # Theme, global CSS
│       └── lib/          # Keybindings, markdown, skills registry
└── shared/               # Types + IPC channel constants

Agent first— the browser is the agent's operating surface, not just a human tool with automation bolted on** Human visible**— the UI should make agent behavior easy to follow, audit, and steer** Persistent by default**— browser state should survive long-running workflows and repeated sessions** Content first**— chrome is 110px, everything else is your page** Easy on the eyes**— warm dark grays, muted text, no visual noise** Linux-native**— frameless window, system font fallbacks, XDG conventions

MIT

Developed by Tyler Williams in Portland, Oregon (2026)

source & further reading

github.com — original article