Vercel AI SDK homepage

Vercel AI SDK

by Vercel

Open-source TypeScript toolkit for building AI apps and agents

FrameworkSupervised

Last reviewed 2026-06-19

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The Vercel AI SDK (also called the AI SDK) is a free, open-source TypeScript toolkit for building AI-powered applications and agents. It gives developers one provider-agnostic API for text generation, structured output, tool calling, and multi-step agent loops (AI SDK Core), plus framework-agnostic UI hooks for streaming chat and generative interfaces (AI SDK UI) across React, Next.js, Svelte, Vue, and Node. It is a developer library, not a standalone agent: autonomy is whatever the developer builds, and in practice apps range from single-shot assistants to bounded tool-calling agent loops. The SDK is one of the most widely used TypeScript AI libraries and is maintained by Vercel, with optional usage-based routing through the Vercel AI Gateway.

What it can do

  • Generate text and structured objects across providers

    Assistant

    Unified generateText, streamText, and generateObject functions work the same across OpenAI, Anthropic, Google, and other providers.

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  • Orchestrate tool-calling agent loops

    Supervised

    An Agent abstraction runs multi-step tool-calling loops with streaming and lifecycle hooks, bounded by developer-set stop conditions.

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  • Build streaming generative UI

    Copilot

    Framework hooks such as useChat stream model output and tool states into React, Next.js, Svelte, and Vue interfaces.

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  • Call MCP tools and external functions

    Supervised

    Connects to MCP servers and developer-defined functions so agents can use tools and external systems.

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Strengths

  • +De facto standard for building AI features in TypeScript, with a large ecosystem and strong docs
  • +Genuinely provider-agnostic: swap models behind one clean API
  • +Excellent streaming and generative-UI integration, especially with Next.js

Limitations

  • −TypeScript/JavaScript only; no Python support
  • −Agent orchestration is lighter than dedicated multi-agent frameworks
  • −Some convenience features lean toward the Vercel platform and paid AI Gateway

Overview

The Vercel AI SDK is a free, open-source TypeScript toolkit for building AI applications and agents. It abstracts away per-provider differences and gives web developers one API for generation, structured output, tool calling, and agent loops, plus UI primitives for streaming chat and generative interfaces.

What it does

AI SDK Core covers text and object generation (generateText, streamText, generateObject), tool calling, and an Agent class that runs bounded multi-step loops. AI SDK UI provides framework hooks (useChat and friends) that stream model and tool output into React, Next.js, Svelte, and Vue. It can call MCP servers and developer-defined functions as tools. Because it is a library, autonomy is developer-defined; realistically most builds are assistants or supervised agents.

Integrations & setup

Supports OpenAI, Anthropic, Google, and most major providers directly or via the Vercel AI Gateway, which routes across providers without per-provider SDKs. Works across the main JS frameworks and Node, and consumes MCP tools.

Pricing

The SDK itself is free and open-source. The optional AI Gateway is usage-based (provider token rates plus gateway), and the Vercel platform has its own freemium and subscription tiers.

Best for / not for

Best for TypeScript and full-stack web teams adding AI features or building web-native agents. Not for Python shops, and not the first pick when you need heavy multi-agent orchestration, where frameworks like LangGraph or CrewAI go deeper.

Alternatives

Mastra is another TypeScript agent framework; LangChain, the OpenAI Agents SDK, and LlamaIndex are broader (and often Python-first) alternatives.

What people are saying

We aggregate real LinkedIn discussion into sentiment for the agents people search most. Vercel AI SDK isn't tracked yet, want it added? Request tracking.

FAQ

Is the Vercel AI SDK free?+

Yes. The SDK is open-source (Apache-2.0) and free to use and self-host. Optional services like the Vercel AI Gateway and the Vercel platform are billed separately, mostly usage-based or subscription.

Can it build autonomous agents?+

It provides the building blocks: tool calling, multi-step loops, and an Agent abstraction. The autonomy of the result is whatever the developer configures. Most apps are assistants or supervised tool-calling agents bounded by explicit stop conditions.

Sources

Last reviewed 2026-06-19

Alternatives & related

Mastra
TypeScript framework for building AI agents and workflows
LangChain
Open-source framework and platform for building and deploying LLM agents
OpenAI Agents SDK
Lightweight open-source framework for building multi-agent workflows
LlamaIndex
Open-source data framework for RAG pipelines and data-grounded agents
LangGraph
Low-level framework for stateful, durable, graph-based LLM agents
CrewAI
Open-source framework for orchestrating role-based, collaborating multi-agent teams