On the evening of August 13, DeepSeek unveiled its inaugural Harness product, DeepSeek Harness. Within a mere 12 hours of its release, the product had already garnered over 50,000 stars on GitHub, a testament to its immediate popularity. So, what precisely is Harness? In essence, if we consider a model as the 'brain,' then Harness functions as the 'hands and feet,' enabling the model to carry out its practical functions. It manages the reading of structured files, the invocation of tools, the handling of context, and the seamless execution of tasks. While the model dictates what can be achieved, Harness ensures that these capabilities are carried out flawlessly.