Build MCP Server (SDK v1.x)

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

When to use this skill

• Building a new MCP server on @modelcontextprotocol/sdk v1.x (single package)
• Adding tools, resources, or prompts to an existing v1 server
• Migrating a v1 server from deprecated APIs (tool(), SSEServerTransport, raw JSON Schema) to current ones (registerTool, StreamableHTTPServerTransport, Zod)
• Wiring authentication on a v1 server — bearer token, OAuth 2.1 via mcpAuthRouter, or custom middleware
• Hardening transports, sessions, or capabilities on a v1 server (Origin validation, session resumability, sampling/elicitation)
• Diagnosing v1-specific runtime errors — RequestHandlerExtra access, capability declarations, JSON Schema 2020-12 conversion

Do NOT use this skill when