texterify-mcp: Skill for Claude Code

Model Context Protocol (MCP)

MCP is an open protocol that standardizes how AI applications connect to external tools, data sources, and workflows. Think of it as USB-C for AI apps.

Architecture: Host (AI app) -> Client (protocol handler) -> Server (exposes capabilities)

Servers expose three primitives:

• Tools -- Functions the LLM can invoke (with user approval)
• Resources -- File-like read-only data (API responses, file contents)
• Prompts -- Pre-written templates for specific tasks

For architecture details, fetch: https://modelcontextprotocol.io/docs/learn/architecture.md

Building an MCP Server (TypeScript)

Install dependencies:

npm install @modelcontextprotocol/sdk zod
npm install -D @types/node typescript

Minimal server with a tool:

import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js"
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js"
import { z } from "zod"

const server = new McpServer({
  name: "my-server",
  version: "1.0.0",
})

server.registerTool(
  "my_tool",
  {
    description: "Describe what this tool does",
    inputSchema: {
      param: z.string().describe("Parameter description"),
    },
  },
  async ({ param }) => {
    // Tool logic here
    return {
      content: [{ type: "text", text: `Result: ${param}` }],
    }
  },
)

async function main() {
  const transport = new StdioServerTransport()
  await server.connect(transport)
  console.error("Server running on stdio")
}

main().catch((error) => {
  console.error("Fatal error:", error)
  process.exit(1)
})

Key Server Patterns

STDIO transport -- Never write to stdout (use console.error()). Stdout is reserved for JSON-RPC messages.

HTTP/SSE transport -- Standard output logging is fine. Use for remote servers.

Error handling in tools -- Return error content, do not throw:

server.registerTool("example", { description: "...", inputSchema: {} }, async () => {
  try {
    const result = await doWork()
    return { content: [{ type: "text", text: JSON.stringify(result, null, 2) }] }
  } catch (err) {
    return {
      content: [{ type: "text", text: `Error: ${(err as Error).message}` }],
      isError: true,
    }
  }
})