Language and Runtime

What programming language and runtime each AI framework targets.

Vercel AI SDK

TypeScript/JavaScript, designed to run across Node.js and edge runtimes, with framework bindings for React, Vue, Svelte, and Angular.

TanStack AI

TypeScript/JavaScript, officially maintained across React, Solid, Vue, Svelte, Preact, and React Native, plus a vanilla JS client as a fallback.

LangChain

Originally Python-first, with a separately maintained LangChain.js/TypeScript port; the Python version still has the deepest integration catalog of the two.

LangGraph

Available for both Python and JavaScript/TypeScript, mirroring LangChain’s dual-language support since it’s built on the same chat-model abstractions.

LlamaIndex

Primarily Python, with a smaller but actively maintained TypeScript package (LlamaIndex.TS) for JS/TS projects.

Mastra

TypeScript-only by design, built by the team behind Gatsby and aimed squarely at JavaScript/TypeScript teams rather than offering a Python counterpart.

CrewAI

Python-only.

Semantic Kernel (Microsoft Agent Framework)

Multi-language by design, supporting C#/.NET, Python, and Java, reflecting its origins as a cross-stack enterprise SDK rather than a JavaScript- or Python-only tool.

Haystack