DeepSeek Harness, command dsh, is an open-source agent harness from DeepSeek AI. It runs as a local Web UI, a headless one-shot command, an SDK server or an ACP server, and almost every part of it is a plugin. HagiCode is a desktop and web AI programming workbench that drives agent CLIs, dsh among them, as its executor. It does not replace dsh; HagiCode starts dsh in its ACP mode and adds sessions, proposals and commit handling around it.
dsh is a developer preview whose own safety notice says it is experimental, unaudited and subject to breaking changes. If you want to explore the harness itself, write plugins or script it, stay with dsh alone. If you want to run it next to other agents with proposals and parallel sessions, HagiCode is the layer for that.