Build MCP SDK

Build and maintain MCP servers using @modelcontextprotocol/sdk v1.x (single package, Zod-based, protocol version 2025-11-25). Covers McpServer, registerTool, registerResource, registerPrompt, transports, OAuth 2.1, sessions, and deployment.

When to use a different skill instead:

• Imports from @modelcontextprotocol/server (split packages) → use build-mcp-sdk-v2
• Handlers use ctx.mcpReq instead of flat extra → use build-mcp-sdk-v2
• Uses the mcp-use wrapper library → use build-mcp-use-server
• Auditing/optimizing an existing server → use optimize-mcp-server

How to detect v1: @modelcontextprotocol/sdk (single package) in package.json. Handlers use (args, extra) with extra.sendNotification, extra.authInfo, extra.signal at the top level.

Core rules: