Weather MCP Server

Model Context Protocol server with integrated micropayment functionality. Built with Bun, TypeScript, and the ATXP payment system for monetizing LLM tool calls.

Features

• MCP Protocol: Standardized tool interface for AI assistants
• Payment Integration: ATXP middleware requiring USDC micropayments per tool call
• Stateless Architecture: Per-request transport isolation for scalability
• Type-Safe: Strict TypeScript with Zod v3 validation
• High Performance: Bun runtime for fast execution

Tech Stack

• Runtime: Bun
• Protocol: MCP
• Payment: ATXP
• Validation: Zod v3
• Server: Express v5

Quick Start

# Install
bun install

# Configure .env
ATXP_CONNECTION="your-atxp-connection-url"
PORT=3000

# Development
bun run dev

# Production
bun run build
bun run start

Architecture

Client → Express → ATXP Payment → MCP Transport → Tool Handler → Response

Each tool call validates payment before execution. The server creates a new StreamableHTTPServerTransport per request to prevent JSON-RPC ID collisions.

Tool Registration

server.registerTool(
  "tool-name",
  {
    title: "Tool Title",
    description: "What it does",
    inputSchema: { param: z.string() },
    outputSchema: { result: z.string() }
  },
  async (params) => {
    await requirePayment({ price: BigNumber(0.01) });
    return {
      content: [{ type: "text", text: JSON.stringify(output) }],
      structuredContent: output
    };
  }
);

API

POST / - Accepts MCP JSON-RPC 2.0 requests

{
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": { "name": "tool-name", "arguments": {} },
  "id": 1
}

TypeScript Config

• verbatimModuleSyntax: true - Explicit type imports required
• moduleResolution: bundler - Optimized for Bun
• strict: true - All strict checks enabled
• noEmit: true - Bun handles compilation

Key Dependencies

• @modelcontextprotocol/sdk - MCP implementation
• @atxp/express - Payment middleware
• zod@^3.23.8 - Required for MCP SDK compatibility
• bignumber.js - Precise monetary calculations

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Built with Bun 🥟