Introducing language model middleware, data stream protocol, and multi-step generations

The AI SDK is an open-source toolkit for building AI applications with JavaScript and TypeScript. Its unified provider API allows you to use any language model and enables powerful UI integrations into leading web frameworks such as Next.js and Svelte .

Since our 3.3 release , we've seen some incredible products built with the AI SDK:

postgres.new is an AI-powered SQL editor that uses the AI SDK to translate user queries into SQL.

v0 is a web development agent that allows you to generate UI, ask engineering questions, and execute code — all in natural language.

v0 by Vercel is powered by the AI SDK

Today, we’re excited to release AI SDK 3.4 which introduces several new features:

Language model middleware : intercept and modify language model calls

Data stream protocol : use AI SDK UI with with any backend

Structured outputs : object, array, or enum-based output modes

Multi-step calls : automatic tool use with…