keel: A DSH plugin that makes agents define specs before writing code

When using harnesses like dsh (DeepSeek Harness)—which adopts a "everything is a plugin" approach—to run coding tasks, the common problem is not that the model cannot write code, but that it starts writing immediately upon receiving requirements. When requirements are vague, the implementation direction can drift, leading to the highest rework costs; treating "I assume" as fact builds solutions on quicksand, and doing too much work during the implementation phase allows the scope to creep further away. While writing specifications into system prompts is a common approach, constraints often remain at the "self-discipline" level and lack a hard gatekeeping mechanism. The philosophy of Keel is to prioritize writing specifications and validating assumptions, with implementation not beginning until the specifications pass the gate. During implementation, rules are used to prevent over-engineering, and change requests are used to prevent scope creep. Before delivery, acceptance criteria are audited item by item. Discipline is achieved by constraining agent behavior through skills and performing deterministic checks via tools, rather than relying on...