facebook pixel
TOOLS · ENPILINK · OPEN SOURCE

Build your MCP App once. Run it in every host.

Enpilink is our open-source TypeScript framework for MCP Apps and ChatGPT Apps: tools that render interactive React views inside Claude, ChatGPT, VS Code, Goose and other hosts.
MIT licensed, account-free, and yours to self-host.

npm create enpilink@latest
Start your first appView it on GitHub ↗
YOUR APP · ONE CODEBASE
src/server.tsregisterTool("greeting")
src/views/greeting.tsxuseToolInfo()
EnpilinkMCP AppsChatGPT Apps SDK
ChatGPT
Hello, Ada!
Claude
Hello, Ada!
VS Code
Hello, Ada!
Goose
Hello, Ada!
SAME VIEW · EVERY MCP APPS HOST
WHAT IT IS

A tool the model calls, with a real interface.

An MCP server gives an AI model tools it can call. An MCP App goes one step further: the tool also returns a view, and the host renders it right inside the conversation. A product list you can click, a form, a chart.

ChatGPT and the open MCP Apps standard run those views on different runtimes. Enpilink puts both behind one React API. You write the server and the views once, and every host gets the version it understands.

ENGINEERING LEADERS

One stack for every host. MIT licensed, built on the official MCP SDK, nothing sent back to us.

FRONTEND DEVELOPERS

It is React and TypeScript. Hooks instead of postMessage, hot reload, typed tool data.

AI DEVELOPERS

See what the model sees. A Console to run every tool, and evals that check a prompt reaches it.

WHY ENPILINK

Everything around the view, already built.

The view is the part you want to write. Runtimes, types, auth, previews and tests are the parts that slow it down.

  • Write once, run in every host

    One server and one set of React views. Enpilink serves both the MCP Apps and the ChatGPT Apps SDK versions, and the view picks the right runtime when it loads.

  • Type-safe end to end

    Tool inputs are zod schemas, and views get typed input and output generated from the server. Rename a field and the type checker tells you, not the chat.

  • A hook for everything a view does

    Call a tool, send a follow-up message, open a link, go fullscreen, keep state across remounts. React hooks, never raw postMessage.

  • Account-free dev, instant tunnel

    One command starts the server, the Console and hot reload. Add --tunnel for a public /mcp URL to paste into Claude or ChatGPT. No signup.

  • A Console for the whole loop

    Dashboard, logs, configuration, a Playground with realistic ChatGPT and Claude previews, and an OAuth debugger, right beside your server.

  • OAuth that is ready for production

    Validate your identity provider’s tokens as a resource server, or run the built-in authorization server with a branded login and guest mode.

  • Tests for what unit tests miss

    Evals check that a natural prompt reaches the right tool with the right arguments. View tests render every view across host, theme and device.

  • Yours to run

    Admin plane secured by default, no telemetry, self-host anywhere Node runs. Built on the official MCP SDK v2 and the 2026-07-28 spec.

HOW IT WORKS

Server tool in. Interface out.

  1. 1
    SERVER

    Define a tool

    Register it on your MCP server with a zod input schema and the name of the view it renders.

  2. 2
    VIEW

    Write the view

    A React component that reads the tool’s typed output and acts through hooks.

  3. 3
    HOST

    The host renders it

    The model calls the tool, and Claude, ChatGPT or VS Code shows your view inline in the chat.

CONSOLE · PLAYGROUND
CLAUDE · LIGHT · DESKTOP
Show me what's in the catalog
Northwind catalogReact view
  • Green SenchaTea
    DetailstoolQuick lookmodalAdd to cartintent
  • Oat Crunch CookiesSnacks
    DetailstoolQuick lookmodalAdd to cartintent
  • Travel Press MugGear
    DetailstoolQuick lookmodalAdd to cartintent
Reply to Claude...

A simplified recreation of the Console’s realistic preview, running the kitchen-sink demo’s catalog view. Switch hosts: the view is the same code.

GET STARTED

This is a whole app.

One tool on the server, one component for its view. The view’s types come from the server, so the two cannot drift apart.

  1. 01 · SCAFFOLD A PROJECT
    npm create enpilink@latest my-app
  2. 02 · SERVER, CONSOLE AND HOT RELOAD
    npm run dev
  3. 03 · A PUBLIC /MCP URL FOR CLAUDE OR CHATGPT
    npm run dev -- --tunnel

Needs Node.js 22 or later. The Console opens at localhost:3000.

src/server.ts

TypeScript
import { McpServer } from "enpilink/server";
import { z } from "zod";
const server = new McpServer({ name: "my-app", version: "0.0.1" }, {})
  .registerTool(
    {
      name: "greeting",
      description: "Greet someone by name.",
      inputSchema: { name: z.string() },
      view: { component: "greeting" },
    },
    async ({ name }) => {
      return { structuredContent: { message: `Hello, ${name}!` } };
    },
  );

src/views/greeting.tsx

TSX
import { useToolInfo } from "../helpers.js"; // auto-generated from server schema
export default function Greeting() {
  const { output } = useToolInfo<"greeting">();
  return <h1>{output.message}</h1>;
}
THE CONSOLE

Watch it, configure it, debug it. In one Console.

The Playground above is one tab of the Console that runs beside your app. The rest covers what happens after the view works. Outside your own machine, it is sign-in gated by default.

Dashboard and logs

Per-tool call volume, latency and error rate, with a live log stream. Recording is opt-in and stays on your server.

CONSOLE · DASHBOARD
Total calls
Success rate
p50 latency
p95 / p99
Tool-call volumeCALLS VS ERRORS
LIVE LOGS
INFOtools/call browse_catalog
INFOtools/call product_details
INFOtools/call view_cart

Configuration

Typed runtime settings, environment over file over database. Secrets stay in the environment, and every change is audited.

CONSOLE · CONFIGURATION
env › file › DB
  • Analytics enabled
    analytics.enabled
  • Live log stream
    flags.liveLogs
  • Event retention
    retention.events
  • Admin token
    ENPILINK_ADMIN_TOKEN
    env only · masked
EVERY CHANGE IN THE AUDIT LOG

OAuth debugger

Walks the MCP sign-in flow one step at a time and checks every response against the spec.

CONSOLE · OAUTH DEBUGGER
Run all
  1. Unauthenticated requestSPEC OK
  2. Protected Resource MetadataSPEC OK
  3. Authorization Server metadataSPEC OK
  4. Client registrationSPEC OK
  5. Authorization request
  6. Token exchange
  7. Authenticated MCP call

View tests

enpilink test views renders each view in both hosts, both themes and both devices, against screenshot baselines.

ENPILINK TEST VIEWS
ChatGPT
light · desktop
ChatGPT
dark · desktop
ChatGPT
light · mobile
ChatGPT
dark · mobile
Claude
light · desktop
Claude
dark · desktop
Claude
light · mobile
Claude
dark · mobile
SCREENSHOT BASELINES PER VIEW

Simplified recreations of the Enpilink Console, redrawn from the kitchen-sink example. Placeholder bars stand in for live values.

START HERE

Your first MCP App is one command away.

Free and open source under the MIT license. Read the code, open an issue, send a pull request.

npm create enpilink@latest
View it on GitHubEnpilink on npm ↗
Shipping one to production and want a hand? Tell us what you are building ↓
Contact

Ready to shift?

We accelerate Frontend delivery. The Frontend Delivery Factory installs the system that lets everyone in your org ship production Frontend.

Senior engineers, AI-native by default, shipping production code in your repo. Fast onboarding. Honest work.

What happens next
  1. 01

    You send the form.

    A few lines on your product and timeline.

  2. 02

    We reply within a day.

    Usually faster. No forms after that.

  3. 03

    We meet and plan.

    Scope, team fit, start date. Then engineers.

0/2000

Your info stays with us. That's it.