Best free OpenAI Agents SDK alternatives

Looking for a free alternative to OpenAI Agents SDK? Here are 9 agent frameworks (developers) worth trying — 9 with a free tier. OpenAI Agents SDK itself is free.

ToolOpenAI Agents SDK (you searched)LangGraphMicrosoft AutoGenGoogle Agent Development Kit (ADK)
Pricingfreefreefreefree
Best forLightweight agent orchestration from OpenAIBuild stateful, multi-agent apps as graphsMulti-agent conversation frameworkOpen-source Python/Java framework from Google for building multi-agent systems
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OpenAI Agents SDK alternatives — straight answers

What is the best free alternative to OpenAI Agents SDK?

LangGraph is the closest free alternative to OpenAI Agents SDK: same Agent Frameworks (Developers) sub-category, and it is free. Build stateful, multi-agent apps as graphs

Are there free OpenAI Agents SDK alternatives?

Yes — 9 of the 9 alternatives listed here are free or freemium: LangGraph, Microsoft AutoGen, Google Agent Development Kit (ADK), Pydantic AI, Mastra. None of them are paid-only.

Is OpenAI Agents SDK free?

OpenAI Agents SDK is free. There is no paid plan attached to it in the catalog.

How were these OpenAI Agents SDK alternatives chosen?

They are the other tools in Agent Frameworks (Developers), then the rest of AI Agents & Automation, ordered free tiers first and capped at 9. There is no sponsorship and no paid placement in that ordering — only the pricing tier decides.

All OpenAI Agents SDK alternatives

Browse Agent Frameworks (Developers) →

LangGraph

Agent Frameworks (Developers)
free

✦ WhyA OpenAI Agents SDK alternative — Build stateful, multi-agent apps as graphs.

  • Build stateful, multi-agent apps as graphs
  • Human-in-the-loop and durable execution
  • Works with any LLM
  • Open-source with a hosted platform

Microsoft AutoGen

Agent Frameworks (Developers)
free

✦ WhyA OpenAI Agents SDK alternative — Multi-agent conversation framework.

  • Multi-agent conversation framework
  • Event-driven, async agent design
  • Studio UI for prototyping
  • Fully open-source

Google Agent Development Kit (ADK)

Agent Frameworks (Developers)
free

✦ WhyA OpenAI Agents SDK alternative — Open-source Python/Java framework from Google for building multi-agent systems.

  • Open-source Python/Java framework from Google for building multi-agent systems
  • Native integration with Vertex AI Agent Engine and Gemini models
  • Model-agnostic — works with non-Google LLMs via LiteLLM

Pydantic AI

Agent Frameworks (Developers)
free

✦ WhyA OpenAI Agents SDK alternative — Type-safe Python agent framework from the Pydantic team, validated structured outputs.

  • Type-safe Python agent framework from the Pydantic team, validated structured outputs
  • Model-agnostic (OpenAI, Anthropic, Gemini, Groq, Mistral, local)
  • Built-in dependency injection and streaming; pairs with Pydantic Logfire for observability

Mastra

Agent Frameworks (Developers)
free

✦ WhyA OpenAI Agents SDK alternative — Open-source TypeScript framework (Apache 2.0) for agents, workflows and RAG.

  • Open-source TypeScript framework (Apache 2.0) for agents, workflows and RAG
  • Drops directly into existing React/Next.js apps or runs standalone
  • Built-in workflow engine with suspend/resume and human-in-the-loop steps

Agno

Agent Frameworks (Developers)
free

✦ WhyA OpenAI Agents SDK alternative — Open-source (Apache-2.0) Python framework, 41.7k GitHub stars.

  • Open-source (Apache-2.0) Python framework, 41.7k GitHub stars
  • AgentOS: FastAPI-based production runtime for deploying agents
  • Control-plane UI for monitoring live agent systems across clouds

smolagents

Agent Frameworks (Developers)
free

✦ WhyA OpenAI Agents SDK alternative — Extremely minimal open-source library (~1,000 lines) from Hugging Face.

  • Extremely minimal open-source library (~1,000 lines) from Hugging Face
  • CodeAgent paradigm: agents write actions as executable code, not JSON
  • Model-agnostic and modality-agnostic (text, vision, audio) with sandboxed execution via E2B/Docker/Modal

AWS Strands Agents

Agent Frameworks (Developers)
free

✦ WhyA OpenAI Agents SDK alternative — Open-source (6,800+ stars) Python and TypeScript SDK from AWS.

  • Open-source (6,800+ stars) Python and TypeScript SDK from AWS
  • Steering handlers/hooks that catch agent mistakes before execution
  • Native Bedrock and AWS AgentCore integration, plus any-LLM support

DSPy

Agent Frameworks (Developers)
free

✦ WhyA OpenAI Agents SDK alternative — Open-source (MIT) framework from Stanford NLP, 37k+ GitHub stars.

  • Open-source (MIT) framework from Stanford NLP, 37k+ GitHub stars
  • Compiles/optimizes prompts automatically against metrics instead of manual prompt tuning
  • Production use at Databricks, Shopify, Dropbox, AWS; Shopify reports ~550x cost reduction

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