mcp-framework / rules

---
description: 
globs: 
alwaysApply: false
---
We are in the mcp-framework , a typescript framework that allows construction of model context protocol (mcp) servers.
We are implementing the new specification:
<specification>Overview 
MCP provides a standardized way for applications to:

Share contextual information with language models
Expose tools and capabilities to AI systems
Build composable integrations and workflows
The protocol uses JSON-RPC 2.0 messages to establish communication between:

Hosts: LLM applications that initiate connections
Clients: Connectors within the host application
Servers: Services that provide context and capabilities
MCP takes some inspiration from the Language Server Protocol, which standardizes how to add support for programming languages across a whole ecosystem of development tools. In a similar way, MCP standardizes how to integrate additional context and tools into the ecosystem of AI applications.

Key Details 
Base Protocol 
JSON-RPC message format
Stateful connections
Server and client capability negotiation
Features 
Servers offer any of the following features to clients:

Resources: Context and data, for the user or the AI model to use
Prompts: Templated messages and workflows for users
Tools: Functions for the AI model to execute</specification>

Here is an example of how a user creats an mcp server using mcp-framework as the library: <example>## src/tools/ExampleTool.ts

```ts
import { MCPTool } from "mcp-framework";
import { z } from "zod";

interface ExampleInput {
  message: string;
}

class ExampleTool extends MCPTool<ExampleInput> {
  name = "example_tool";
  description = "An example tool that processes messages";

  schema = {
    message: {
      type: z.string(),
      description: "Message to process",
    },
  };

  async execute(input: ExampleInput) {
    return `Processed: ${input.message}`;
  }
}

export default ExampleTool;
```

## src/index.ts

```ts
import { MCPServer } from "mcp-framework";

const server = new MCPServer({transport:{
  type:"http-stream",
  options:{
    port:1337,
    cors: {
      allowOrigin:"*"
    }
  }
}});

server.start();

```

## package.json

```json
{
  "name": "http2-hi",
  "version": "0.0.1",
  "description": "http2-hi MCP server",
  "type": "module",
  "bin": {
    "http2-hi": "./dist/index.js"
  },
  "files": [
    "dist"
  ],
  "scripts": {
    "build": "tsc && mcp-build",
    "watch": "tsc --watch",
    "start": "node dist/index.js"
  },
  "dependencies": {
    "mcp-framework": "^0.2.12-beta.4",
    "zod": "^3.24.4"
  },
  "devDependencies": {
    "@types/node": "^20.11.24",
    "typescript": "^5.3.3"
  },
  "engines": {
    "node": ">=18.19.0"
  }
}

```
</example>

It's important to keep in mind that mcp-framework is used exclusively as a dependency in other repositories - just like express js would be.
This means that we are running it from node_modules within the repo - this impacts how relative directories work