OpenHarness is an open-source agent harness from HKUDS that provides the core infrastructure modern AI agents need: tool use, skills, memory, and multi-agent coordination in one lightweight package. It ships with ohmo, a built-in personal agent designed to actually work for you over long sessions rather than just chat. The project has over 16,000 stars on GitHub, with its latest updates in June 2026.
Every serious agent product needs the same plumbing: a loop that calls tools, a way to load skills, memory that persists, and coordination when several agents work together. OpenHarness packages that plumbing as reusable infrastructure, so builders can focus on their agent’s job instead of reinventing the runtime. Its built-in personal agent, ohmo, demonstrates the stack end to end: it chats with you in apps like Feishu, Slack, and Telegram, takes on tasks, and keeps working across long sessions with memory of what came before. The project comes from the same HKUDS lab behind several popular open agent projects.
OpenHarness and ohmo are completely free and open source under the MIT license. Your only costs are hosting and any model APIs you connect.
OpenHarness is for agent builders who want solid runtime infrastructure without adopting a heavyweight platform, and for users who want to try ohmo as a hard-working personal agent in their everyday chat apps.