- Prompts for an "As a / I want to / So that" user story (three structured questions)
- Runs SPIDR splitting check — if the story is too large, walks through Spike/Paths/Interfaces/Data/Rules and offers to split into multiple phases
- Writes
**Mode:** mvpand the reformatted**Goal:**to the phase's ROADMAP.md section - Delegates to
/ferrox plan-phase <N>which auto-detects MVP mode via the roadmap field
Phase 1 of the vertical-mvp-slice PRD shipped the planner-side machinery; this command is the user entry point for it.
The phase must already exist in ROADMAP.md (created via /ferrox new-project, /ferrox add-phase, or /ferrox insert-phase). This command does not create new phases — it converts an existing phase to MVP mode.