DeepSeek Harness is an open-source agent harness that provides a plugin-based platform for building and running AI agents.
The tool addresses the need for a flexible, composable architecture to develop AI agents by implementing an everything-is-a-plugin design powered by Cordis. This approach allows developers to build modular agent systems where functionality can be added, removed, and composed through plugins rather than monolithic code. The harness includes a web UI accessible at localhost by default and can be run either through npm or from source using pnpm.
Developers should adopt this tool if they are building agent systems that benefit from plugin extensibility and modular composition. It suits projects where multiple capabilities need to be independently developed and integrated. The tool is in developer preview with rapid iteration, so teams should be prepared for compatibility-breaking changes and should review the safety notice before deployment.
The project shows active development with ongoing iteration on core architecture and plugin systems. Documentation is maintained across multiple guides covering user workflows, development practices, and agent-specific implementation. The maintainers actively solicit community feedback through GitHub Discussions and provide multiple channels for contribution and support including a Discord community.
