architect

# Architect On Codex, read the [platform mapping](../poteto-mode/references/codex-tools.md), including its per-skill notes, before following this skill. Design before implementing. Sketch types, function signatures, class shapes, and module boundaries with `not implemented` bodies and pseudocode. Synthesize across multiple model perspectives, then fill in code against the chosen sketch. If implementation proves the sketch wrong, throw it out and redesign. ## Start Open a todolist with one entry per phase before starting. 1. Ground 2. Sketch 3. Agree 4. Implement 5. Scrap ## Phase A: Ground the problem Build a real mental model of every system the new code touches. Run the **how** skill over the relevant subsystems. Naming a file isn't grounding. Produce the traced model `how` prescribes. If the design redefines ownership or layering, also run the **why** skill on the existing shape so the rationale becomes a constraint, not a guess. Skip Phase A only when the work is genuinely greenfield with no surrounding system to integrate. ## Phase B: Sketch Run the **arena** skill with the design-sketch task and the Phase A grounding artifacts. Pass `references/runner-prompt.md` as each runner's prompt. Each candidate produces a design package shaped per `references/rationale-template.md`. Use your configured architect runners (defaults in [Models](#models)). Design it twice. Require at least two structurally distinct candidates before synthesis, even when the first looks s...