Best AI Agent Tools on GitHub in 2026: 15 Open-Source Projects with Real Star Counts

15 open-source AI agent tools on GitHub, ranked by real stars pulled from the API on 2026-07-31.

## Best AI Agent Tools on GitHub in 2026 Star counts below were fetched from the GitHub API on 2026-07-31 by the ainomam star tracker. Use them as a popularity signal, not a quality verdict. ### Agent frameworks (build your own agent) 1. **langchain-ai/langchain** - 143,097 stars. The agent engineering platform, now with LangGraph for stateful agents. 2. **microsoft/autogen** - 60,129 stars. Multi-agent conversation framework from Microsoft. 3. **joaomdmoura/crewAI** - 56,432 stars. Role-based agent crews, very approachable for beginners. 4. **phidatahq/phidata** - 41,526 stars. Build, run, and manage agent platforms. ### Ready-to-run agents 5. **All-Hands-AI/OpenHands** - 82,697 stars. The open-source AI software engineer. 6. **anthropics/claude-code** - 139,794 stars. Claude terminal coding agent. 7. **openai/codex** - 102,894 stars. OpenAI lightweight coding agent. 8. **cline/cline** - 65,313 stars. VS Code autonomous coding agent. ### Tool ecosystem 9. **modelcontextprotocol/servers** - 89,093 stars. Official MCP servers (filesystem, GitHub, Slack). 10. **punkpeye/awesome-mcp-servers** - 91,652 stars. Curated list of 10,000+ MCP servers. 11. **browser-use/browser-use** - 107,406 stars. Make websites accessible to AI agents. 12. **composiohq/composio** - 40k+ stars. 250+ integrations for agent tool use. ### Orchestration and memory 13. **n8n-io/n8n** - 198,849 stars. Fair-code workflow automation with native AI capabilities. 14. **mem0ai/mem0** - 62,202 stars. Universal memory layer for AI agents. 15. **langflow-ai/langflow** - 152,678 stars. Visual builder for agentic workflows. ### How to choose New to agents? Start with crewAI for simplicity or n8n for no-code. Building production software? LangGraph. Need a coding assistant today? Install cline in VS Code. ### FAQ **Which one is most popular?** n8n at 198,849 stars, followed by langflow and open-webui. **Are these all free?** All listed are open-source; claude-code and codex have paid tiers for heavy usage.