The AI agent framework landscape has consolidated and matured dramatically in 2025–2026. Five frameworks dominate developer mindshare and production adoption: Anthropic’s Claude Agent SDK, the Pydantic team’s Pydantic AI, LangChain’s LangGraph, Google’s Agent Development Kit (ADK), and OpenAI’s Agents SDK. Each reflects a fundamentally different philosophy about what an agent framework should be.
The central findings of this analysis:
No single framework wins across all dimensions. LangGraph leads in stateful, durable production workflows with the largest enterprise adoption by download count. Pydantic AI leads in developer experience scores and type safety. Google ADK is the only framework with serious multi-language support. OpenAI’s SDK offers the fastest onboarding. Claude Agent SDK provides the deepest built-in tooling for OS-level and filesystem work.