--- source_url: "https://vulpineos.com/?utm_source=openai" title: VulpineOS - An operator system for browser agents mirrored_at: 2026-08-20T03:01:42.634Z host: vulpineos.com cited_in_42a: true mirror_canonical: "https://index.42a.ai/vulpineos.com/index__q__utm_source_openai" --- > **Original source:** https://vulpineos.com/?utm_source=openai Open source · MPL 2.0 ## The runtime thatmakes browser_agents finally work._ VulpineOS runs AI agents that navigate the web as reliably as a human, blending in, handling surprises, and cutting through the noise. Open source. Self-hosted. Drop in your LLM keys and go. The problem ## Browsers were not designed for AI. Your agents pay the price. PROBLEM 01PROMPT INJECTION ### Your agent follows instructions it should never see. Websites hide text in elements the human never notices. Your agent reads everything and attackers exploit that to rewrite its instructions mid-task. → one hidden paragraph can hijack your agent PROBLEM 02PAGE MUTATION ### The page your agent sees is already stale. Between reading the page and taking action, timers fire, elements shift, modals appear. Your agent acts on a page that no longer exists. → your agent acts on a page that no longer exists PROBLEM 03TOKEN WASTE ### Most of what your agent reads is useless. Accessibility trees are full of scaffolding and wrappers. Your model pays per token to read a page you already understand. The cost adds up fast. → you pay for reasoning, not page scaffolding Architecture ## Four layers of reliability. One pipeline from page to prompt. Built at the browser level so your agent never has to work around browser limitations. INPUThostile web page OUTPUTsafe, compact snapshot PHASE 01 / 04 INJECTION FILTER ### Strip everything the agent should not see. Hidden text, invisible elements, offscreen content. Anything the human would not encounter gets removed before the agent ever reads it. hidden textinvisible elementsoffscreen content Stealth & network ## Your agent looks like a person on every site. Every session the site sees a unique browser profile. Consistent across WebGL, fonts, timezone, locale. Bring your own proxies and the runtime keeps everything in sync automatically. Unique identity per session WebGL, canvas, audio, fonts, and timezone stay consistent across the stack Your proxies, auto-synced Plug in your own residential pool. Geolocation, timezone, locale, and WebRTC IP all re-sync on each rotation. Pre-warmed profiles Profiles age across innocuous sites before hitting the target Network-level cover JA3/JA4 spoofed to match the fingerprinted browser identity Fleet at scale ## Run a fleet, not a script. A fleet of agents working in parallel, each with its own identity, instructions, and budget. Manage them from one panel or let cost alerts and webhooks handle the monitoring. CONCURRENT ~200 Active agents on a 32GB / 16-core workstation. Scales with your hardware: more on bigger nodes, less on a laptop. Bring your own LLM and proxies. ORCHESTRATION A2A bus Agent-to-agent messaging built in. One agent can spawn, supervise, or hand off to another, with cost ceilings and approval gates. LLM PROVIDERS 30+ Anthropic, OpenAI, Google, xAI, Groq, Mistral, Cerebras, OpenRouter, Ollama, and many more. Drop in your API key and switch providers per agent. MCP TOOLS 36 Browser navigation, clicks, downloads, screenshots, audio, and mobile are exposed as MCP tools that any LLM can call directly. Token savings ## Pay for reasoning, not scaffolding. Most browser snapshots are full of wrappers, separators, and repetition. VulpineOS strips everything the model does not need. You keep the structure and the text, not the scaffolding. Chrome full AX tree~42,832 tokens Raw page HTML~12,761 tokens Playwright ariaSnapshot~11,577 tokens VulpineOS optimized export~2,942 tokens 93.1% Measured reduction vs compact Chrome AX tree 74.6% Measured reduction vs Playwright ariaSnapshot 39.9M Input tokens avoided per 1,000 snapshots vs compact Chrome AX The landscape ## Everything your agents need. Nothing they don’t. Other tools give you a browser and call it a day. VulpineOS gives you a browser runtime tuned for AI agents, with protections that cannot be bolted on later. Feature VulpineOS Playwright Puppeteer Browserbase Browserless C++ injection-proof a11y filter — — — — Action-Lock page freeze (nsDocShell) — — — — Token-optimized DOM export — — PARTIAL — Anti-detect fingerprints — — — Built-in proxy rotation (BYO pool) — — PARTIAL — Self-host runtime — — Multi-agent orchestration built in — — — — Open source license — — Comparisons as of April 2026 · based on publicly-available product documentation. Features ## What you can do with it. 01 Invisible to anti-bot systems Every session looks like a real person on a real device. Consistent fingerprints across WebGL, fonts, and timezone. 02 Your agent follows your instructions Hidden text and injected prompts are stripped before the agent ever sees them. 03 Reliable actions, every time The page freezes while your agent decides. No timing issues, no surprise modals. 04 Smaller prompts, lower costs Snapshots are 90% smaller than standard browser output. You pay for reasoning, not markup. 05 Structured data, not guesswork Your agent returns typed, validated JSON. No parsing, no surprises. 06 Bring your own proxies Use the pool you already have. The runtime keeps location and fingerprints in sync through every rotation. 07 Any model you want Pick the best LLM for each task. Switch providers per agent without changing your setup. 08 36 tools out of the box Navigation, clicks, downloads, screenshots, audio, mobile. Every action is an MCP tool your agent can call. 09 Control your spend Per-agent budgets with soft and hard limits. Webhooks when costs cross your thresholds. Built in the open ## Built in public. Free to use. The whole stack is open source under MPL 2.0. Fork it, extend it, build on it. Contribute upstream or keep your changes private. FOXBRIDGE ### Plug Firefox-based browsers into anything that speaks CDP. An open-source protocol translator exposes a Chrome DevTools Protocol surface on top of Juggler and WebDriver BiDi. CDP-native agent stacks drive Vulpine browser through the same endpoint, with fingerprint isolation per session. ``` $ foxbridge --binary /path/to/vulpine --port 9222 ✓ Vulpine browser 146.0.1 detected ✓ Juggler bridge online ✓ WebDriver BiDi backend ready CDP endpoint ws://localhost:9222/devtools/browser drive with: openclaw, playwright, puppeteer, … ``` Clone, build, ship ## Ship your first agent today. Clone the repo, add your LLM keys, and run. All under MPL 2.0. Open source underMPL 2.0Vulpine browser · Firefox 146.0.1Built on Firefox 146