Exnos

Live browser-state verification for AI coding agents. Free, by GOL Productions.

Your coding AI says "Done." Exnos is how it knows. One tool call returns the real state of the Chrome tab you are looking at, in milliseconds: URL, title, every visible field with its live value, every button with its disabled state, checkboxes, visible alerts, console errors since page load, scroll position, and the visible text. Read-only by design. Exnos never touches the page.

How it works

coding AI  --MCP(stdio)-->  exnos server  --WebSocket(localhost)-->  Chrome extension  -->  the live page

No debug port. No relaunching Chrome. Works with the normal Chrome you already have open.

Install (2 minutes)

1. Connect your coding agent (Claude Code)

Add to your MCP config (works in any MCP client, any OS - Claude Code .mcp.json, Cursor, Windsurf, anything that speaks MCP):

{ "mcpServers": { "exnos": { "command": "npx", "args": ["@golproductions/exnos"] } } }

Any other MCP-capable agent: run npx @golproductions/exnos as a stdio MCP server. No paths to type, nothing to quote.

2. Load the extension

Print where the extension lives:

npx @golproductions/exnos path

Then open chrome://extensions, turn on Developer mode (top right), click "Load unpacked", and pick that folder. The Exnos badge reads ON when it finds the server, OFF when it is waiting.

Tools

Tool	What it returns
exnos_verify	Full live state of the active tab. Optional tab (substring of URL/title) targets another tab; optional selector also returns that element's text, visibility, and HTML.
exnos_tabs	All open tabs: title, URL, which is active.

Notes

• Server listens on 127.0.0.1:17872 (override with EXNOS_PORT).
• GET http://127.0.0.1:17872/ returns {"exnos":true,"extension":true|false} for a quick health check.
• If the server or Chrome restarts, the extension reconnects by itself within seconds.
• Internal pages (chrome://, web store) cannot be inspected; Exnos says so instead of guessing.
• Console errors are captured from page load by a tap injected at document_start; pages opened before the extension loaded need one reload to start capturing.

License and trademarks

Exnos is free software under the MIT license. The copyright notice must stay in all copies, that is the license's own condition. The names "Exnos" and "GOL Productions" and the Exnos logo are trademarks of GOL Productions and are not licensed under MIT. Forks must use a different name and must not imply endorsement by GOL Productions.

Free forever. Made by GOL Productions.