Open source · self-hostable
Best open-source agent frameworks
The open-source agent frameworks in the index — self-hostable, inspectable, and free to run. Ranked by real maintained adoption (GitHub stars and recent commit activity), never by sponsorship. Open source buys you control, privacy, and no vendor lock-in; the trade-off is that you host and maintain it yourself. Right now it's led by langchain (144k stars), with ruflo and autogen close behind. Rankings shift as projects gain stars and ship commits.
langchainThe agent engineering platform.Python · 144k stars · MIT · Aug 2026Python · 144k stars · MITrufloThe leading agent meta-harness. Deploy intelligent multi-player swarms, coordinate autonomous workflows, and build conversational AI systems.TypeScript · 68k stars · MIT · Aug 2026TypeScript · 68k stars · MITautogenA programming framework for agentic AIPython · 60k stars · CC-BY-4.0 · Apr 2026Python · 60k stars · CC-BY-4.0crewAIFramework for orchestrating role-playing, autonomous AI agents. By fostering collaborative intelligence, CrewAI empowers agents to work together seamlessly, tackling complex tasks.Python · 57k stars · MIT · Aug 2026Python · 57k stars · MITpydantic-aiAI Agent Framework, the Pydantic wayPython · 19k stars · MIT · Aug 2026Python · 19k stars · MITelizaOpen source agentic operating systemTypeScript · 19k stars · MIT · Aug 2026TypeScript · 19k stars · MITSuperAGI<> SuperAGI - A dev-first open source autonomous AI agent framework. Enabling developers to build, manage & run useful autonomous agents quickly and reliably.Python · 18k stars · MIT · Jan 2025Python · 18k stars · MITagent-frameworkA framework for building, orchestrating and deploying AI agents and multi-agent workflows with support for Python and.NET.Python · 13k stars · MIT · Aug 2026Python · 13k stars · MIThiveMulti-Agent Harness for Production AIPython · 11k stars · Apache-2.0 · Aug 2026Python · 11k stars · Apache-2.0evolverThe GEP-powered self-evolving engine for AI agents. Auditable evolution with Genes, Capsules, and Events. | evomap.aiJavaScript · 9.0k stars · GPL-3.0 · Aug 2026JavaScript · 9.0k stars · GPL-3.0UpsonicBuild autonomous AI agents in Python.Python · 7.9k stars · MIT · Jun 2026Python · 7.9k stars · MITyaoBuild AI agents and web apps — with a single binary.Go · 7.6k stars · Aug 2026Go · 7.6k stars · Aug 2026
harness-sdkBuild an agent harness and control it end-to-end. Open-source SDK for production AI agents in Python & TypeScript - any model, any cloud.Python · 6.9k stars · Apache-2.0 · Aug 2026Python · 6.9k stars · Apache-2.0open-multi-agentTypeScript multi-agent orchestration framework. Describe a goal, a coordinator decomposes it into a task DAG that runs on any LLM: Claude, ChatGPT, Gemini, DeepSeek, or local models.TypeScript · 6.8k stars · MIT · Aug 2026TypeScript · 6.8k stars · MITintentkitIntentKit is an open-source, self-hosted cloud agent cluster that manages a collaborative team of AI agents for you.Python · 6.5k stars · MIT · Aug 2026Python · 6.5k stars · MITagent-governance-toolkitAI Agent Governance Toolkit — Policy enforcement, zero-trust identity, execution sandboxing, and reliability engineering for autonomous AI agents. Covers 10/10 OWASP Agentic Top 10.Python · 6.0k stars · MIT · Aug 2026Python · 6.0k stars · MITagentsAn Open-source Framework for Data-centric, Self-evolving Autonomous Language AgentsPython · 6.0k stars · Apache-2.0 · Sep 2024Python · 6.0k stars · Apache-2.0rllmDemocratizing Reinforcement Learning for LLMsPython · 5.8k stars · Apache-2.0 · Aug 2026Python · 5.8k stars · Apache-2.0ag2AG2 (formerly AutoGen): The Open-Source AgentOS.Join us at: https://discord.gg/sNGSwQME3xPython · 4.9k stars · Apache-2.0 · Aug 2026Python · 4.9k stars · Apache-2.0youtu-agentA simple yet powerful agent framework that delivers with open-source modelsPython · 4.6k stars · Mar 2026Python · 4.6k stars · Mar 2026fast-agentCode, Build and Evaluate agents - excellent Model and Skills/MCP/ACP/A2A SupportPython · 3.9k stars · Apache-2.0 · Aug 2026Python · 3.9k stars · Apache-2.0opengapA framework-agnostic, git-native standard for defining AI agentsTypeScript · 2.9k stars · MIT · Jul 2026TypeScript · 2.9k stars · MITVibe-SkillsVibe-Skills is an all-in-one AI skills package.Python · 2.9k stars · Apache-2.0 · Aug 2026Python · 2.9k stars · Apache-2.0harmonistPortable AI agent orchestration with mechanical protocol enforcement. 186 agents, zero runtime dependencies.Python · 2.3k stars · MIT · Jun 2026Python · 2.3k stars · MITverl-agentverl-agent is an extension of veRL, designed for training LLM/VLM agents via RL. verl-agent is also the official code for paper "Group-in-Group Policy Optimization for LLM Agent Training"Python · 2.2k stars · Apache-2.0 · Jun 2026Python · 2.2k stars · Apache-2.0yomoServerless AI Agent Framework with Geo-distributed Edge AI Infra.Rust · 1.9k stars · Aug 2026Rust · 1.9k stars · Aug 2026DemoGPTCreate LLM agents in a second with your prompts. Everything you need to create an LLM Agent - tools, prompts, frameworks, and models - all in one place.Python · 1.9k stars · MIT · Apr 2026Python · 1.9k stars · MITAgently[GenAI Application Development Framework] Build GenAI application quick and easy Easy to interact with GenAI agent in code using structure data and chained-calls syntax Use Event-Driven FlowPython · 1.6k stars · Apache-2.0 · Aug 2026Python · 1.6k stars · Apache-2.0flowcraftProduction-grade Go SDK for building AI agents with long-term memory, knowledge retrieval, and voice — runnable as a library, a daemon, or a real-time pipeline.Go · 416 stars · MIT · Aug 2026Go · 416 stars · MIT
Frequently asked
- What are the best open-source agent frameworks?
- The projects listed below, ranked by maintained adoption — GitHub stars plus recent activity — so you see what's genuinely used and still maintained, not abandoned.
- Are open-source agent frameworks free?
- The software is free to run and self-host. You still pay for the infrastructure you run it on and any model or API usage it makes.
- Open-source or commercial agent frameworks — which should I choose?
- Pick open source for control, privacy, and no lock-in when you're happy to host and maintain it; pick a commercial product for a managed, supported experience. You can compare both in the full agent frameworks category.