AI SDK 5

What this post added

AI SDK 5 introduces a redesigned chat with separate UI and model messages, enabling easier persistence. It adds customizable UI messages via generics for full-stack type safety. 'Data parts' allow streaming type-safe, arbitrary data from server to client, with support for transient parts. Tool invocations are now type-safe with specific part identifiers for tools, automatic input streaming, and explicit error states. Message metadata can be attached to messages for additional context. Experimental speech generation and transcription are also introduced, along with V2 specifications for AI models, a global provider, and access to raw responses. Zod 4 support is also included.