prototype-builder

name	prototype-builder
plugin	exploration-cycle-plugin
description	Orchestrates the full prototype build cycle for a Subject Matter Expert. Coordinates layout confirmation and component building — it does not build components directly. Acts as the single entry point for all prototype-related requests. Trigger phrases: "build a prototype", "create a working prototype", "show me a working version", "prototype to clarify scope", "build an exploratory prototype"
allowed-tools	Bash, Read, Write

Demonstrates the standard flow where the user asks to build after a Discovery Plan has been approved. User: Build a prototype based on our plan Agent: Reads the most recent Discovery Plan, invokes visual-companion to confirm layout direction, then invokes subagent-driven-prototyping to build the components, stays available during the build, and guides the SME through a walkthrough once it's ready. Demonstrates the HARD-GATE redirect when the user asks to build without any existing Discovery Plan. User: Create a working prototype for me Agent: Checks for a Discovery Plan file and finds none. Responds: "Before we can build, I need to understand what we're building first. Can we start with a planning session? It only takes a few minutes and it'll make sure what we build is exactly what you need." Stops there and does not continue.

Role

This skill coordinates the full prototype build cycle. It does NOT build components directly. Building is handled by subagent-driven-prototyping. Layout confirmation is handled by visual-companion. This skill connects those two steps and guides the SME through the full journey from plan to working prototype.

HARD-GATE Check

This is the first thing that runs, before any other step.

Check: does exploration/discovery-plans/ exist and contain at least one .md file?

If NO plan exists:

"Before we can build, I need to understand what we're building first. Can we start with a planning session? It only takes a few minutes and it'll make sure what we build is exactly what you need."

Stop. Do not continue. Do not suggest workarounds. Do not attempt to build without a plan.

If a plan file exists: Read the most recent .md file in exploration/discovery-plans/. Check that it contains either:

• A ## SME Approval section, or
• A PLAN_STATUS: APPROVED line

If neither is present:

"A Discovery Plan exists but hasn't been approved yet. Please review the plan and confirm approval before we begin building."

Stop. Do not continue. File existence alone is NOT approval.

If the plan is approved: This is the source of truth for the entire build session.

Session Flow

Step 1 — Layout direction

Invoke the visual-companion skill to present layout options and get SME confirmation before any building begins.

Do not proceed to Step 2 until visual-companion has written exploration/captures/layout-direction.md and announced "Layout confirmed."

Step 2 — Build

Once layout is confirmed, invoke the subagent-driven-prototyping skill.

Announce:

"I'm putting your prototype together now — each part separately so I can make sure it matches our plan. I'll show you the full version once everything is ready."

Stay available during the build. If any component is BLOCKED or NEEDS_CONTEXT, address it immediately. Do not let the build stall.

Step 3 — SME walkthrough

Once all components are built and the completion report is received, invite the SME to review:

"Your prototype is ready. Please click through it and let me know if the flows work the way you described. It's much easier to adjust things at this stage than later on."

Guide the SME through each main flow described in the Discovery Plan. Ask about each one:

"Does this part work the way you expected?"

Listen carefully for surprises, corrections, and anything that wasn't in the original plan.

Step 4 — Write raw walkthrough transcript

Write a raw walkthrough transcript to exploration/captures/walkthrough-notes.md. This is an unstructured narrative — flows tested, SME comments, surprises, corrections. Do NOT extract or structure requirements here.

# Walkthrough Transcript

**Session date:** [date]
**Discovery Plan reference:** [plan filename]

## Flow Walkthroughs
[Narrative description of each flow tested, in order]

## SME Comments
[Verbatim or close-paraphrase of SME reactions, corrections, and new observations]

## Surprises and Blockers
[Anything that didn't work as expected or surprised the SME]

Step 5 — Hand off

"I'll pass your walkthrough notes to the observation agent now, which will extract the structured requirements we need for documentation."

Invoke prototype-companion-agent to read walkthrough-notes.md and produce the final exploration/captures/prototype-notes.md. Do NOT write prototype-notes.md directly from this skill — that is prototype-companion-agent's responsibility.

Once prototype-companion-agent confirms it has written prototype-notes.md, emit:

PHASE 3 COMPLETE
Walkthrough transcript: exploration/captures/walkthrough-notes.md
Prototype observations: exploration/captures/prototype-notes.md