Every web app
is an API
Web apps already have internal APIs — the same ones their frontends use. OpenTabs reverse-engineered them and exposed them as MCP tools today. Your AI calls the same backend the frontend calls — through your browser, using your existing session. No screenshots. No DOM. No guessing.
Works with
And any MCP client that supports Streamable HTTP.
100+ plugins. ~2,000 tools.
Each one talks to the real web app through your authenticated session.
Plus built-in browser tools for any tab.
And 90+ more — messaging, DevOps, finance, shopping, streaming, and beyond. Browse all plugins
How it works
OpenTabs is a Chrome extension and MCP server. Your AI agent sends a tool call, it gets routed to the right browser tab, and the action happens on the real web app.
Your AI sends a tool call
Claude, Cursor, or any MCP client calls a tool like discord_send_message — just a normal MCP tool call.
OpenTabs routes it to the right tab
The MCP server finds the matching browser tab and dispatches the call through the Chrome extension.
It runs on the real web app
The plugin calls the same internal API the frontend calls, using your logged-in session. Results flow back to the agent.
Get plugins
Point your AI at any website
It analyzes the page, discovers the APIs, scaffolds the code, and registers the plugin. Most of the plugins in this repo were built by AI in minutes.
A self-improving skill teaches AI agents the process — and gets better with every plugin built. Publish yours or keep it local for internal tools.
Plugin development guideInstall from npm
100+ plugins ready to go. Install globally and the server picks them up automatically.
Safe by default
Your browser sessions are precious. Everything is off until you turn it on — and you control exactly how much trust to give each plugin.
Everything starts off
Every plugin's tools are disabled by default — even the ones I ship. You shouldn't have to trust me blindly.
AI-assisted code review
When you enable a plugin, your AI can review the adapter source code first. You see the findings and decide.
Version-aware
When a plugin updates, permissions reset. New code, new review.
Full audit log
Every tool call is logged — what ran, when, whether it succeeded.
Runs locally. No cloud. No telemetry. The code is open source — read it.
FAQ
How is this different from browser automation (Playwright, Stagehand, Browser-Use)?
Browser automation simulates what a human would do — click, type, read the screen. Works on any site out of the box, but the cost is speed, tokens, and the knowledge stays trapped in that one session. OpenTabs plugins call the web app's internal APIs directly. A send-message tool isn't clicking a text box — it's making the same API call the frontend makes. Fast, cheap on tokens, and the knowledge is packaged into a reusable plugin. The tradeoff is you need a plugin per site, and internal APIs can change.
What about Chrome's WebMCP?
WebMCP is the right long-term direction — websites opt in and expose tools to AI agents natively. But adoption depends on every service choosing to participate, and that takes years. OpenTabs is the proactive version: reverse-engineer the APIs and expose them today. If WebMCP becomes widespread, plugins can evolve to use it.
2,000 tools? Won't that blow up my context window?
No. OpenTabs has three connection modes — pick the one that fits. Full MCP gives you everything upfront. Gateway exposes 2 meta-tools and lets your AI discover the rest on demand. CLI mode has zero MCP overhead — your AI just calls opentabs tool call via shell. Most users enable 3–5 plugins and only those tools load into context. Learn more
Why not just use official MCP servers?
If one works well for you, use it. OpenTabs started for apps that don't have MCP support. Along the way, I noticed: setting up separate API keys for each service adds up, public APIs sometimes have stricter rate limits, and the web app is always the superset. I see OpenTabs and official servers as complementary — mix and match.