mb-skill-concept

name	mb-skill-concept
tier	skill
calls	[]
description	Generate N concept variations of a site / asset on localhost in parallel, foreground subagents. Default 2. Operator picks one to publish. Used by /mb-site as the concept-generation step.
loops	["ship"]

skill-concept

A composable skill for generating concept variations. /mb-site calls this after the brief is locked, before the first publish.

Inputs

• The locked brief (path provided in the user message)
• Reference URLs (taste anchors, not templates)
• Conversion endpoint config (.mainbranch/conversion.json)

Outputs

• N localhost-runnable HTML variations, each in its own subdir of the project repo (e.g., concepts/v1/, concepts/v2/)
• A short comparison summary for the operator: hero artifact, palette, voice variant for each
• Operator picks one; that variation is promoted to the project root

Flow

1. Spawn N foreground subagents (default 2). Each gets the same brief + reference URLs but is asked to make different decisions.
2. Each subagent writes its variation. Foreground only — background writes are known to silently fail.
3. Validate each variation: footer present, OG.svg under 1200×630, no AI tells in the copy.
4. Render preview. python3 -m http.server from each subdir; open in browser.
5. Operator picks. One concept → promoted to repo root; others archived under concepts/.

Foreground rule

Subagents MUST be foreground. The known background-subagent file-write bug means files appear written but don't persist. Foreground only. See references/concept-variations.md for the spawn pattern.

Cross-references

• references/concept-variations.md
• references/minisite-generation-system.md