designlisted

# X2 Design (Claude Design) Produce one whole-product prototype and its design system from the source of truth. This runs in its own context, deliberately separate from the builder: the pilot showed that when the builder is also the designer, the design steps collapse and acceptance criteria get authored backwards (turn 8). Design is done once for the whole product; each slice locks its portion later. ## Inputs - D-000: the story set, the recorded product decisions, the module shape, the slice definitions. - The behaviour spec beside it, if the product has one. The prototype must make that behaviour visible; it is the difference between designing the product and designing a generic UI. - The design brief, where one exists (required for a rich domain, see below). It governs the information architecture where it is more specific than the stories. ## The design brief (requirements-for-design in its positive shape) For a simple domain, the input beyond the stories is a thin note: novel-or-irreversible only. For a rich domain (many surfaces, typed variants, a domain model the stories do not carry), the method requires the brief, produced in the product working session with the human and approved by the human as a decision turn BEFORE this skill runs: 1. **The domain model is frozen as a decision first** (a D-0xx). The brief renders that decision; it cites it and never restates it. 2. **The brief carries exactly three kinds of content:** - Topology: the user journey