Categories / Agent frameworks
Agent frameworks
Libraries for building your own AI agents.
Picks changed this week: none. These picks were first published on 2026-10-15.
Why it wins: TypeScript toolkit for LLM apps and agents across providers.
Pick something else if you want a fuller TypeScript framework with workflows (Mastra) or you work in Python (LangGraph, OpenAI Agents SDK, CrewAI).
Visit Vercel AI SDK →Last verified 2026-10-16Alternatives
Mastra
TypeScript agent framework with workflows, memory and evals.
Free, open source coreLast verified 2026-10-16
LangGraph
Graph-based, stateful agents in Python/JS.
Free, open source · LangSmith from $0, Plus $39/seatLast verified 2026-10-16
OpenAI Agents SDK
Lightweight Python SDK for multi-agent workflows.
Free, open source (you pay for API usage)Last verified 2026-10-16
CrewAI
Role-based multi-agent crews in Python.
Free, open source · platform Basic freeLast verified 2026-10-16Compare at a glance
| Tool | Pricing | Open source | Platform | Best for (our take) | Last verified |
|---|---|---|---|---|---|
 Vercel AI SDK top | Free, open source | Yes (Apache-2.0) | Library | TypeScript LLM apps | 2026-10-16 |
| Mastra | Free, open source core | Yes (Apache-2.0 core; ee/ excluded) | Library | TypeScript agents with workflows | 2026-10-16 |
| LangGraph | Free, open source · LangSmith from $0, Plus $39/seat | Yes (MIT) | Library | Stateful Python/JS agents | 2026-10-16 |
| OpenAI Agents SDK | Free, open source (you pay for API usage) | Yes (MIT) | Library | Lightweight Python agents | 2026-10-16 |
| CrewAI | Free, open source · platform Basic free | Yes (MIT) | Library | Role-based multi-agent | 2026-10-16 |
Every pricing, open-source and platform fact was checked by hand on the tool's own pricing page, docs or official GitHub repo (license file). Click a fact to open its source. Open source means an OSI-approved license in the official repo; source-available licenses such as FSL are labeled as such. Anything we couldn't confirm is marked unverified, not guessed.
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