AI SDK

Vercel's open-source TypeScript framework for building AI apps across 16+ providers with unified streaming, tools, and UI hooks.

Free· Open source (Apache 2.0); pay only for the underlying model APIsCodingMulti-model

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Best for

Pick AI SDK if you're a TypeScript developer building chat, agent, or generative features and want provider portability without writing the streaming plumbing yourself.

Skip if

Skip it if you're working in Python, need deep model-specific features (e.g. raw OpenAI Realtime), or want a hosted product rather than a library.

AI SDK is a TypeScript-first toolkit from Vercel that abstracts the differences between LLM providers behind a single, consistent API. It ships as the `ai` npm package (around 15.8M weekly downloads) and breaks into two main parts: AI SDK Core for text/image/speech/transcription/video generation, tool calling, and agent loops; and AI SDK UI, a set of framework-agnostic hooks (React, Next.js, Vue, Svelte) that make chat, completion, and streaming UIs trivial to wire up.

It's aimed squarely at full-stack TypeScript developers who want to ship AI features without re-implementing streaming, retries, structured output, and tool-calling glue for every provider. Switching from OpenAI to Anthropic to Google is essentially a one-line change in the `model:` argument, which makes it ideal for teams that want optionality or are running A/B tests across providers. The SDK itself is free and open-source (Apache 2.0, 25k+ GitHub stars); you pay only for the underlying model APIs you call.

It integrates cleanly with the rest of Vercel's stack (AI Gateway for unified billing/rate limiting, Sandbox for code execution, Workflows for orchestration), but nothing forces you to deploy on Vercel. Caveats: it's TypeScript/JavaScript only, the API surface has evolved quickly across major versions, and 'multi-provider' still means writing against the lowest common denominator of features.

Editor's take

The de facto standard for AI in the TypeScript world. If you're shipping a Next.js app with any LLM feature, the cost of not using AI SDK is reinventing streaming and tool-calling glue for every provider. The churn between major versions is real, but the abstraction has earned its place.

— The AI Tool Bible editorial team

Pros

✅ One API across OpenAI, Anthropic, Google, Mistral, xAI, Meta and 10+ more providers
✅ First-class streaming, tool calling, and structured output baked in
✅ Framework-agnostic UI hooks for React, Next.js, Vue, and Svelte
✅ Open source, Apache 2.0, maintained by Vercel with active community
✅ Battle-tested at scale (15M+ weekly npm downloads)

Cons

⚠️ TypeScript/JavaScript only - no Python or Go bindings
⚠️ Frequent breaking changes across major versions
⚠️ Provider parity is lowest-common-denominator; some model-specific features are awkward