AI SDK 5

AI SDK 5 introduces a redesigned chat with explicit UIMessage and ModelMessage types for improved persistence and type safety. It adds 'data parts' for streaming arbitrary, type-safe data between server and client, and enhances tool invocations with type-specific identifiers, automatic input streaming, and explicit error states. Experimental speech generation/transcription, tool improvements, V2 specifications, a global provider, access to raw responses, and Zod 4 support are also included.