wong2/litemcp

A TypeScript framework for building MCP (Model Context Protocol) servers elegantly
> Deprecate notice:
> Since the official SDK already offers a high-level API similar to this project, this project will no longer be maintained.
> If you like the CLI commands in this project, you can use them independently: https://github.com/wong2/mcp-cli
## Features
Simple Tool, Resource, Prompt definition
Full TypeScript support
Built-in logging
Built-in error handling
Built-in CLI for testing and debugging
Built-in support for SSE transport
## Installation
bash
npm install litemcp zod
## Quickstart
js
import { LiteMCP } from "litemcp";
import { z } from "zod";
const server = new LiteMCP("demo", "1.0.0");
server.addTool({
name: "add",
description: "Add two numbers",
parameters: z.object({
a: z.number(),
b: z.number(),
}),
execute: async (args) => {
return args.a + args.b;
},
});
server.addResource({
uri: "file:///logs/app.log",
name: "Application Logs",
mimeType: "text/plain",
async load() {
return {
text: "Example log content",
};
},
});
server.start();
You can test the server in terminal with:
bash
npx litemcp dev server.js
## Core Concepts
### Tools
Tools in MCP allow servers to expose executable functions that can be invoked by clients and used by LLMs to perform actions.
js
server.addTool({
name: "fetch",
description: "Fetch the content of a url",
parameters: z.object({
url: z.string(),
}),
execute: async (args) => {
const content = await fetchWebpageContent(args.url);
return content;
},
});
### Resources
Resources represent any kind of data that an MCP server wants to make available to clients. This can include:
File contents
Screenshots and images
Log files
And more
Each resource is identified by a unique URI and can contain either text or binary data.
js
server.addResource({
uri: "file:///logs/app.log",
name: "Application Logs",
mimeType: "text/plain",
async load() {
return {
text: await readLogFile(),
};
},
});
You can also return binary contents in load:
js
async load() {
return {
blob: 'base64-encoded-data'
### Prompts
Prompts enable servers to define reusable prompt templates and workflows that clients can easily surface to users and LLMs. They provide a powerful way to standardize and share common LLM interactions.
js
server.addPrompt({
name: "git-commit",
description: "Generate a Git commit message",
arguments: [
name: "changes",
description: "Git diff or description of changes",
required: true,
},
],
load: async (args) => {
return Generate a concise but descriptive commit message for these changes:\n\n${args.changes};
},
});
### Logging
You can send log messages to the client with server.logger
js
server.addTool({
name: "download",
description: "Download a file from a url",
parameters: z.object({
url: z.string(),
}),
execute: async (args) => {
server.logger.info("Downloading file", { url: args.url });
// ...
server.logger.info("Downloaded file", { url: args.url });
return response;
},
});
The logger object has the following methods: