Both sit in the framework layer with similar commercial terms, so the practical split is language: Pydantic AI targets Python and Vercel AI SDK targets TypeScript.
Type-safe Python agents with structured output that actually validates.
Streaming-first TypeScript SDK with a unified provider interface and UI hooks.
| Pydantic AI | Vercel AI SDK | |
|---|---|---|
| Licence | Open source | Open source |
| Pricing | open source | open source |
| Self-hostable | Yes | Yes |
| Languages | Python | TypeScript |
| Install | pip install pydantic-ai | npm install ai |
| Keys required | None | None |
Both sit in the framework layer with similar commercial terms, so the practical split is language: Pydantic AI targets Python and Vercel AI SDK targets TypeScript. Pydantic AI: Type-safe Python agents with structured output that actually validates. Vercel AI SDK: Streaming-first TypeScript SDK with a unified provider interface and UI hooks.
Pydantic AI can run on your own infrastructure. Vercel AI SDK can run on your own infrastructure.
Pydantic AI is open source (open source). Vercel AI SDK is open source (open source).
Every page here answers to Accept: text/markdown and returns the same content at roughly a tenth the tokens. No separate site, no toggle — same URL.
curl -s -H "Accept: text/markdown" https://newagent.build/compare/pydantic-ai-vs-vercel-ai-sdk