DeepSeek Harness Hands-On: Four Work Modes, 'Model + Harness = Agent', and the Most Ambitious Agent Open Source of the Year

DeepSeek Harness launched its developer preview and open-sourced the code at 8:30 PM on August 13. A first-night hands-on review finds the product shell still early at v0.1 but the architecture ambition the biggest of the year: four preset work modes, an everything-is-a-plugin philosophy, and the equation Model + Harness = Agent.