Best Google Agent Development Kit Alternatives in 2026

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

OpenAI's own agent framework — agents, handoffs, guardrails and sessions over the Responses and Chat Completions APIs, with tracing built in and Python and TypeScript implementations that track each other.

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

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

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

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.

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.

Create agentic, context engineered AI systems using Haystack’s modular and customizable building blocks, built for real-world, production-ready applications.

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