NanoApps

What it does

NanoApps simplifies the creation of MCP Apps by allowing developers to build self-contained tools paired with interactive HTML UIs that render inline within MCP-compatible clients. It provides a high-level API (defineApp) to define tool logic and UI resources in a single package.

Key features

• Unified Tool & UI: Define tool handlers and their corresponding HTML/CSS/JS UIs in a structured directory.
• Bun-Powered: Optimized for the Bun runtime for fast execution and development.
• Flexible App Types: Supports single-tool apps with UI, tool-only apps, and multi-tool apps sharing a single UI resource.
• Built-in Auth: Integrated support for passing authentication context from HTTP middleware to tool handlers.
• Standalone Builds: Ability to bundle all dependencies into a single JS file for easy deployment.

Installation

Install via Bun:

bun add nanoapps zod

To serve as an MCP server (HTTP), mount the mcpHandler in a Hono app or use the provided CLI:

bunx nanoapps run

Supported hosts

Confirmed for Claude Desktop and other MCP-compatible clients via the standard MCP specification.