eMCP

What is eMCP?

eMCP is a fork of the LiteMCP TypeScript library that adds built-in authentication handling and custom layered middleware support. It is designed as a near drop-in replacement for LiteMCP, with all added features being optional.

How to use eMCP?

Install via npm or Bun (npm i emcp or bun add emcp). You can run provided examples (bun run example:basic, bun run example:auth, etc.). Create a server instance by passing an authenticationHandler function and use server.use() to add custom middleware that runs before and after the standard MCP handler.

Key features of eMCP

• All existing LiteMCP features preserved
• Built‑in authentication handler for requests
• Custom layered middleware support (runs in registration order)
• Near drop‑in replacement for LiteMCP

Use cases of eMCP

• Add authentication checks to every tool, resource, or prompt call
• Log request‑response cycles with timing via middleware
• Build complex MCP servers with reusable middleware layers
• Migrate existing LiteMCP projects without major code changes

FAQ from eMCP

How is eMCP different from LiteMCP?

eMCP extends LiteMCP with an optional built‑in authentication handler and a custom middleware system, while remaining a near drop‑in replacement.

How does middleware execution work?

Middleware runs in the order it was registered. Each middleware calls next(), then the standard MCP handler runs. After the handler completes, middleware code after next() executes in reverse order.

What runtime or dependencies are required?

eMCP is a TypeScript library that requires Node.js with npm or Bun. It is installed via npm i emcp or bun add emcp.

Is authentication mandatory?

No, the authentication handler is optional. If not set, requests proceed without authentication.

Does eMCP support custom transports?

The README does not mention specific transports; it inherits the transport capabilities of LiteMCP (e.g., stdio, SSE).