/parallel-build

name: parallel-build
description: Spin up multiple website or page variants in parallel — each in its own git worktree or sibling folder, built by a sub-agent from the same brief and shared design tokens but a different inspiration source — then cherry-pick and merge the best sections into one final. Captures side-by-side comparison screenshots when Playwright is connected; otherwise renders a structured comparison summary. Trigger when the user says "parallel build", "build three versions", "spin up variants", "make 3 sites at once", "side-by-side build", or "different design flavors to compare".

parallel-build

**Family:** build-and-qa **Status:** Stable

Purpose

The multi-variant build primitive: instead of one prompt → one site, spawn N sub-agents (default 3), each in its own worktree/folder, each given a different inspiration source but the **same brief and the same design tokens**. The user gets a side-by-side comparison and cherry-picks the best sections into a merged final.

Triggers

• "parallel build" / "build three versions" / "spin up variants"
• "make 3 sites at once" / "side-by-side build"
• "different design flavors to compare"

Inputs

• Target (business/page/client) + the brief
• N variants (default 3) and N inspiration sources (one per variant; `html-extract`

can supply them)

• Output mode: git worktrees | sibling folders

Steps

1. **Capture** the brief and the N inspiration sources. 2. **Generate shared tokens once** with `design-system-gen` so all variants share a coherent palette/type/effects — consistency across variants, distinctiveness via inspiration + layout. 3. **Create N output locations** — git worktrees (one per variant) or, if git isn't available, sibling folders `variant-1/ … variant-N/`. 4. **Dispatch N build sub-agents in parallel** behind the shared-token barrier — each runs the `design-build` skill with the same brief + the one shared token set from step 2, differing only by inspiration source. (`design-build` is an orchestrator, so each variant runs it as a skill inside its own sub-agent — not as a dispatched-leaf agent; the barrier guarantees every variant shares one palette/type/effects system.) One-shot each (iterate only if needed). 5. **Collect** outputs and render a side-by-side comparison. When Playwright is connected, fan out one `design-visual-qa` agent per variant for screenshot capture and cross-variant diffs; otherwise render a structured comparison summary. 6. **Cherry-pick + merge.** The user picks sections from each; assemble the final and run `qa-gate` before delivery.

Outputs

• N variant builds in their output locations
• A side-by-side comparison artifact
• The merged final (after the user picks)

Dependencies

• `design-system-gen` (required) — generates the shared tokens once so every variant

shares one palette/type/effects system

• `design-build` (required) — runs the per-variant build inside each sub-agent
• `html-extract` (optional — adds auto-sourced inspiration per variant; free path: user

supplies the inspiration sources)

• `design-visual-qa` (optional — adds side-by-side comparison screenshots via Playwright;

free path: structured comparison summary)

• `qa-gate` (optional — adds a structured PASS/FAIL gate on the merged final; free path:

manual review before handoff)

• Sub-agent dispatch + git worktrees (optional — falls back to sibling folders

`variant-1/ … variant-N/`)

Notes

Shared tokens + divergent inspiration is the formula: variants feel like one brand exploring directions, not three unrelated sites.