mcp-kit: Universal MCP Toolkit
Universal MCP (Model Context Protocol) toolkit for building servers across all JavaScript runtimes — Node.js, Bun, Cloudflare Workers, and edge platforms.
The Problem
Building Model Context Protocol (MCP) servers today means choosing a runtime and getting locked in. Node.js servers don’t run on edge. Edge workers can’t do filesystem operations. Developers end up maintaining separate codebases for different deployment targets.
The Solution
mcp-kit provides a single codebase that runs across all JavaScript runtimes — Node.js, Bun, Cloudflare Workers, Vercel Edge, and Netlify Edge. Built on the ultra-fast Hono framework with automatic runtime detection and conditional feature loading.
Key Features
- Universal Runtime Support: Single codebase for Node.js, Bun, Cloudflare Workers, Vercel Edge, Netlify Edge
- Hono Framework: Lightweight HTTP framework chosen for fast startup and cross-runtime portability
- Cross-Runtime Compatibility: Automatic runtime detection and conditional feature loading
- Type-Safe Tool Handlers: Strongly typed MCP tool definitions with validation
- Multi-Target Builds: Separate optimized builds for different runtime environments
- Multi-Instance Coordination: Version-aware upgrade flow for production deployments
Architecture
The toolkit separates universal features (available everywhere) from local features (Node.js/Bun only), ensuring that edge deployments never bundle unnecessary code while local deployments get full filesystem and process management capabilities.