smolagents

LangGraph

langchain-ai/langgraph

Popular

Low-level graph framework for stateful, durable agents with human-in-the-loop; the most deployed agent runtime.

OpenAI Agents SDK

openai/openai-agents-python

Trending

Lightweight agent SDK with handoffs, guardrails, sessions and tracing; works with non-OpenAI models too.

Claude Agent SDK

anthropics/claude-agent-sdk-python

TrendingNew (detected automatically)

The agent harness behind Claude Code as a library: tools, subagents, MCP, hooks and context management.

CrewAI

crewAIInc/crewAI

Popular

Python framework for role-based multi-agent crews and event-driven flows; popular for business automation.

Microsoft Agent Framework

microsoft/agent-framework

New

Successor to Semantic Kernel and AutoGen for .NET and Python agents and graph workflows; GA since April 2026.

Google ADK

google/adk-python

Rising

Google's Agent Development Kit for code-first multi-agent systems, optimized for Gemini and Vertex AI.

Pydantic AI

pydantic/pydantic-ai

Trending

Type-safe agent framework from the Pydantic team, with dependency injection, structured output and evals.

Mastra

mastra-ai/mastra

Trending

TypeScript agent framework with workflows, memory, RAG, evals and a local dev playground.

Deep Agents

langchain-ai/deepagents

New

LangChain's harness for long-running agents with planning, subagents and a virtual file system.