What problem does it solve? Founders and builders often jump into coding before validating demand, defining a target user, or stress-testing their assumptions. This Skill runs a YC-style office hours conversation that forces rigorous thinking about an idea before any code is written, and captures the outcome as a durable design document. ## Core Features & Use Cases - Two brainstorming modes: Startup mode applies six forcing questions (demand reality, status quo, narrowest wedge, future-fit); Builder mode applies design-thinking brainstorming for side projects, hackathons, and open source. - Design doc generation: Writes a structured design document to ~/.gstack/projects/{slug}/ with problem statement, premises, approaches considered, and success criteria, including a Supersedes chain linking revisions across sessions. - Adversarial spec review loop: Dispatches an independent reviewer subagent to score the document on completeness, consistency, clarity, scope, and feasibility, iterating up to 3 rounds before handoff. - Use Case: You have a rough idea for a developer tool and ask "is this worth building?" The Skill walks you through demand evidence and wedge definition, challenges your premises, optionally pulls a second opinion from another model, and saves an approved design doc that downstream skills like /plan-eng-review can consume. ## Quick Start Ask the agent to run office hours to brainstorm and pressure-test your new product idea before writing any code.
