Agent frameworks · ranked 01
Vercel AI SDK
Also known as AI SDK
TypeScript toolkit for streaming, tool calls, and chat UI.
Best for Streaming AI features in a TypeScript web app
The Vercel AI SDK is an open-source TypeScript toolkit for building AI apps: streaming responses, tool calling, structured output, and UI hooks for React and other frameworks. It is provider-agnostic. It is the default harness in this directory for an indie web app that needs an assistant or a small agent.
Best use cases
- Chat and tool calls in Next.js
- Swapping model providers without rewriting the UI
- A first agent that does not need a heavy framework
Pros
- + Open source and free
- + The React hooks match how the rest of the app is built
- + Works with more than one model provider
Cons
- − Long-running multi-agent systems will want a thicker framework
- − You still pick and pay a model provider
Pricing
Open source and free. Model provider fees are separate. Rates: check site.
Alternatives
Agent frameworks
8.0
Mastra
TypeScript framework for agents, workflows, and evals.
Best for TypeScript agents you keep in your repo
Agent frameworks
6.7
LangChain
The original LLM application framework, plus a hosted LangSmith side.
Best for A general LLM app framework with a huge ecosystem
Agent frameworks
7.6
Pydantic AI
Python agent framework from the Pydantic team, typed end to end.
Best for Typed Python agents