Official MCP Go SDK released, maintained with Google

The repo provides the main github.com/modelcontextprotocol/go-sdk/mcp package for building MCP clients and servers, plus a jsonrpc package for custom transports, an auth package with OAuth primitives, and an oauthex package for OAuth extensions like ProtectedResourceMetadata. The SDK aims for full MCP spec coverage, with a docs/ directory mapping spec features to packages. The compatibility table shows v1.7.0 supports the latest MCP spec 2026-07-28 and remains backward compatible with 2025-11-25, 2025-06-18, 2025-03-26, and 2024-11-05; v1.0.0 to v1.1.0 only support 2025-06-18 and earlier. roots, sampling, and logging are marked deprecated in protocol 2026-07-28, and the SDK keeps compatibility through at least a twelve-month deprecation window. Go developers building MCP servers can now initialize mcp.Server, register tools with mcp.AddTool, and run over stdin/stdout via StdioTransport or CommandTransport; on the client side, connect with mcp.NewClient and call session.CallTool. Earlier third-party Go MCP libraries like mcp-go, mcp-golang, and go-mcp remain usable, but the official SDK offers clearer spec coverage and version alignment, suited to teams that need to track MCP protocol evolution or worry about lagging third-party support. New versions are released only for still-supported Go versions.