ggui is the universal MCP-UI protocol — a runtime-negotiated data contract between AI agents and human users.

Docs · Template repos · Releases

🚧 Active development — iterating on v0.1.0 release candidates. APIs are converging; pin exact versions (see badges below) and watch Releases for the next RC and the v0.1.0 final.

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Agents describe what they need in natural language; ggui generates ephemeral, interactive interfaces over MCP. No frontend code, no React templates, no custom components — agents talk, users see UI.

This repo is the open protocol + reference runtime. Self-host with ggui serve; pair against any MCP-aware agent runtime (Claude Desktop, Claude Code, claude.ai, Cursor, ChatGPT desktop, Goose, your own). Zero account required, zero managed infrastructure required, zero cloud dependency.

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Quick start — pick your path

1. Build an agentic app from a template (recommended for new apps)

The fastest path to ship an agent end-to-end. One command scaffolds a complete pnpm monorepo — chat UI + agent loop + a sample MCP server — pinned to your agent SDK; one more runs the whole thing.

npx @ggui-ai/create-agentic-app --agent claude-agent-sdk my-app
# or:  --agent openai-agents-sdk   |   --agent google-adk
cd my-app && pnpm install
cp .env.example .env.local   # add your LLM API key
pnpm dev                     # starts ggui + MCP servers + agent + web, then opens the app

pnpm dev brings all four services up together and opens http://localhost:6890 once it's ready — so you never have to guess which port to visit (server logs are hidden by default; pnpm dev --verbose streams them). The full loop runs locally: you type → the agent calls domain tools and renders a React UI → you click in that UI → the agent reacts.

Each template subdir at github.com/ggui-ai/agentic-app-templates is a complete project with its own README + CLAUDE.md and a /bootstrap Claude Code command that walks you through customisation: the system prompt, your own MCP servers (drop a folder under servers/mcps/ — it's auto-started by pnpm dev and auto-registered with the agent), blueprints, and gadgets.

2. Self-host the OSS MCP server + test from claude.ai

For testing the ggui protocol against a real chat host. Localhost won't work from claude.ai — you need a public HTTPS URL, which cloudflared provides for free.

# terminal 1 — boot the OSS MCP server
npm install -g @ggui-ai/cli
ANTHROPIC_API_KEY=sk-… ggui serve --mcp-only       # http://127.0.0.1:6781/mcp

# terminal 2 — expose it to the public internet (no Cloudflare account needed)
cloudflared tunnel --url http://127.0.0.1:6781     # prints https://<random>.trycloudflare.com

Then in claude.ai → Settings → Connectors → Add custom connector, paste https://<random>.trycloudflare.com/mcp. Ask Claude to render any UI; the server generates the component and serves it back as a rich rendered card inside the chat.

Install cloudflared via your package manager: brew install cloudflared (macOS), apt install cloudflared (Debian), or grab a binary from cloudflare.com/products/tunnel.

3. Use the hosted ggui.ai cloud — mcp.ggui.ai (deploying soon)

For production, sign up at ggui.ai → create an app → get a managed MCP URL (form: https://mcp.ggui.ai/<app-id>/mcp). Paste into your chat host's connector settings — no self-hosting, no tunnel, no key management.

🚧 The hosted endpoint is deploying — coming in a follow-up rc. Use path 1 or 2 in the meantime.

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The ggui CLI

@ggui-ai/cli ships the ggui binary — the single entrypoint for every OSS workflow. Five verbs cover the full lifecycle:

Verb	What it does
ggui serve	Boot the OSS MCP server (/mcp), session viewer (/r/<shortCode>), pairing endpoints, and live-channel WebSocket. --mcp-only skips agent supervision — fastest first-run. --port, --host adjust binding.
ggui dev	Local UI registry + compile-on-demand dev hub for iterating on a ggui.json project. Optional tunnel, agent supervision, browser auto-open. Run ggui --help for the full flag list.
ggui blueprint	Author + publish + install cached UI templates — create, publish, install. Blueprints make a known screen cheap, fast, and visually consistent by matching before falling back to full LLM generation.
ggui gadget	Author + publish + install client-side libraries (maps, charts, camera, clipboard, anything) wrapped as ggui hooks/components so the generator can use them — create, publish, install.
ggui theme	Validate and inspect ggui.json#theme DTCG documents — ggui theme validate <path>. Catches schema errors before they reach the runtime.

Plus auth verbs for the hosted path: ggui login / ggui logout / ggui whoami / ggui keys. Run ggui --help for the top-level overview, or ggui <verb> --help for per-command flags.

Full CLI reference: @ggui-ai/cli README.

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Runnable examples

samples/ holds end-to-end examples you can clone:

• samples/gguis/ — ready-to-run project configs (default, leaflet-demo, mapbox-demo, canvas-demo) showing how a ggui.json is shaped.
• samples/agents/ — reference agents per SDK (Claude Agent SDK, OpenAI Agents SDK, Google ADK) talking to ggui as an MCP server. These same samples are what the template repo's /bootstrap fetches.
• samples/gadgets/ — example component / hook gadgets for the marketplace.
• samples/mcp-servers/ — minimal domain MCP servers (e.g. a todo server) you can pair against.

Honest scope today

• ✅ Local server, viewer, cookie-authenticated WebSocket subscribe → ack all work end-to-end.
• ✅ ggui_render mints shortCodes and lands on the same-origin viewer.
• ✅ Component-code generation is wired on the OSS path via createUiGenerator() from @ggui-ai/ui-gen (the same harness the hosted runtime uses). ggui_render returns codeReady: false only when no BYOK credentials resolve (no ANTHROPIC_API_KEY / OPENAI_API_KEY / etc.); supply a key to get full generation locally.
• 🔒 Default auth is dev-mode (any non-empty bearer → builder). Swap in a real AuthAdapter via createGguiServer({ auth }) before exposing beyond 127.0.0.1.

How it works

┌─────────┐     MCP Tools      ┌──────────┐     WebSocket     ┌──────────┐
│  Your   │ ────────────────→  │  ggui    │ ────────────────→ │  User's  │
│  Agent  │   ggui_render      │  server  │   real-time UI    │  browser │
│         │   ggui_update      │          │   updates         │          │
│         │ ←────────────────  │          │ ←──────────────── │          │
│         │   user events      │          │   clicks, forms   │          │
└─────────┘                    └──────────┘                   └──────────┘

Your agent uses MCP tools to push UIs and receive user events. The protocol is defined by @ggui-ai/protocol; the reference server lives in @ggui-ai/mcp-server; embedding primitives ship in @ggui-ai/react.

MCP tools (primary surface)

Tool	Description
ggui_render	Render a UI for the user (natural-language prompt + data)
ggui_update	Update props on an existing UI (no regeneration, ~200ms)
ggui_handshake	Initial session bootstrap
ggui_consume	Long-poll for user gestures (clicks, form submits)

Plus a blueprint family (ggui_search_blueprints, ggui_render_blueprint, ggui_list_featured_blueprints, …) for catalogue lookups. Full reference: MCP Protocol Reference.

Zero agent code (MCP config only)

If your agent runtime supports MCP natively, skip the SDK entirely. Add ggui serve as an MCP server:

{
  "mcpServers": {
    "ggui": {
      "url": "http://127.0.0.1:6781/mcp",
      "headers": { "Authorization": "Bearer dev" }
    }
  }
}

The runtime's native tool-calling loop discovers ggui_render, ggui_update, ggui_consume, and the blueprint catalogue tools directly. Working examples per framework: Claude, OpenAI, Gemini, generic MCP.

Embedding UIs

<McpAppIframe> is the canonical consumer primitive. It takes an MCP Apps resource and mounts the ggui render inside a same-origin iframe. The iframe owns the WebSocket lifecycle, renderer bundle, and render mount — host code does not touch Render / WebSocket / renderer internals.

import { McpAppIframe, type ProtocolError } from "@ggui-ai/react";
import { useEffect, useState } from "react";

function App({ renderId }: { renderId: string }) {
  const [resource, setResource] = useState<{ uri: string; mimeType: string; text: string } | null>(
    null
  );

  useEffect(() => {
    // Fetch the render-resource envelope from your MCP host. On the
    // OSS path the renderer route at /r/<shortCode> embeds the
    // bootstrap inline, so a resource with just `{ uri }` is enough.
    fetchRenderResource(renderId).then((r) => setResource(r.contents[0]));
  }, [renderId]);

  if (!resource) return <p>Loading…</p>;

  return <McpAppIframe resource={resource} onError={(err: ProtocolError) => console.error(err)} />;
}

Implementer references for the full protocol: Architecture overview, MCP Apps support, WebSocket protocol.

For non-React frameworks, embed the viewer directly:

<iframe src="http://127.0.0.1:6781/r/{shortCode}" width="100%" height="600"></iframe>

Packages

Consumer-facing surface — what you npm install:

Package	Purpose	npm
@ggui-ai/cli	The ggui binary — serve, dev, blueprint, gadget, theme
@ggui-ai/mcp-server	Reference OSS server (programmatic embedding)
@ggui-ai/react	React embedding — <McpAppIframe> + shells
@ggui-ai/react-native	React Native embedding — WebView-backed renderer
@ggui-ai/protocol	Wire types (events, sessions, WebSocket, MCP envelopes)
@ggui-ai/gadgets	Author wrappers for 3rd-party libs (Leaflet, Mapbox, …)

Plus 27 supporting packages under packages/ spanning the runtime (@ggui-ai/mcp-server-core, @ggui-ai/mcp-server-handlers, @ggui-ai/ui-gen, @ggui-ai/negotiator), authoring (@ggui-ai/project-config, @ggui-ai/ui-registry), registry (@ggui-ai/registry-core, @ggui-ai/registry-server), and dev tooling (@ggui-ai/dev-stack, @ggui-ai/agent-runtime, @ggui-ai/console). See each subdirectory for details.

Hosted providers

Self-hosting is the primary path. For managed infrastructure (no server to run, no LLM key to wire, hosted dashboards), the first-party hosted endpoint at mcp.ggui.ai is deploying — see path 3 above. Guuey hosts an upgraded experience built on top of the protocol. The protocol is identical on all paths — you can move between self-hosted and hosted without rewriting anything against this SDK.

Contributing

See CONTRIBUTING.md. Issues + PRs welcome.

License

Apache 2.0 — see LICENSE.