AI SDK 3.4

What this post added

AI SDK 3.4 introduces language model middleware for intercepting and modifying LLM calls (e.g., for RAG, logging, caching, guardrails), a data stream protocol to use AI SDK UI with any backend, structured output modes (object, array, enum) for better control over LLM responses, multi-step calls for automatic tool use, improved tracing for telemetry, mock models for testing, and provider updates.