Vercel AI SDK

The Vercel AI SDK is a TypeScript toolkit for building AI-powered applications with React, Vue, Svelte, and Node.js. We built this to provide a unified, framework-agnostic interface to 20+ AI providers (OpenAI, Anthropic, Google, Mistral, etc.) with powerful streaming capabilities and type-safe structured outputs.

Our monorepo architecture separates concerns into three layers: Core SDK (unified API for text generation, streaming, objects), Provider Packages (20+ AI provider integrations), and UI Integrations (React, Vue, Svelte, Angular hooks/composables). This design lets developers switch between AI providers with zero code changes - just swap the model parameter.

🎯 Why We Built It This Way

We needed to solve three key problems:

Provider lock-in - Each AI provider has different APIs, making switching costly and time-consuming
Streaming complexity - Real-time streaming UIs require complex state management and SSE handling
Type safety - LLM outputs are unpredictable; we needed structured, validated responses with Zod schemas

Our solution: a three-layer architecture that abstracts provider differences, handles streaming automatically, and enforces type safety through schema validation. This reduced integration time from days to minutes.

📦 Key Repository Stats

200 files organized in a pnpm monorepo with changesets for versioning
20+ provider packages - OpenAI, Anthropic, Google, Azure, Mistral, Groq, XAI, and more
4 UI framework integrations - React, Vue, Svelte, Angular with shared utilities
15+ example apps showing Next.js, Express, Fastify, Nuxt, SvelteKit integrations
Apache 2.0 licensed - open source by Vercel and Next.js team

💡 Design Decision: We chose a monorepo structure to share common utilities (provider-utils, ui-utils) across packages while allowing independent versioning per provider. This reduces duplication and ensures consistency.

See the main README and contributing guide for development setup.