Best OpenAI Agents SDK Alternatives in 2026

Framework for building stateful, multi-actor AI agent applications with cycles, controllability, and persistence — built on LangChain.

Google's open agent framework — hierarchical multi-agent composition, graph workflows that mix deterministic code with model reasoning, a local dev UI and evaluation harness, and a deployment path onto Vertex AI Agent Engine. Python, TypeScript, Go, Java and Kotlin.

Typed Python agent framework from the Pydantic team — one agent loop with every model a string swap away, validated structured output, and the same agent runnable behind a web frontend, a CLI, a voice call or a durable queue.

Framework for orchestrating role-playing autonomous AI agents that collaborate to solve complex tasks.

Agno pairs the fastest framework available with the first enterprise-ready agentic operating system, AgentOS. Build, run, and manage secure multi-agent systems inside your cloud.

LangChain provides the engineering platform and open source frameworks developers use to build, test, and deploy reliable AI agents.

Microsoft's open-source SDK for integrating LLMs into applications with AI agents, planners, and plugin architecture.

Unlock agentic workflow with Dify. Develop, deploy, and manage autonomous agents, RAG pipelines, and more for teams at any scale, effortlessly.

Open-source data framework for connecting private data to LLMs — ingestion, chunking, indexing and retrieval for RAG, with LlamaCloud for managed parsing and indexing.