prototype

Prototype

A prototype is a question the codebase poses to reality. It is explicitly not production code: no tests, no review, no PRD, no ADR, no manifest pinning. The output is a one-page report that tells the team whether the assumption holds — and whatever was learned along the way.

Outputs:

• prototypes/<name>/ — the prototype's code (intentionally walled off from src/)
• prototypes/<name>/REPORT.md — what was built, what was learned, what to do with the learning

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Purpose / When to Run

Run when:

• The concept doc's "Riskiest Assumption" needs validation before architecture commitment
• A novel mechanic or framework feature needs to be tried before adding to a PRD
• A perf concern needs a quick measurement before locking budgets
• A library / SDK needs vetting before an ADR commits to it

Do not run for:

• Features that already have PRDs and ADRs (use /dev-story in the second skill set)
• Bug investigations (use the bug-fix workflow in the second skill set)
• Refactors of existing code (those are real stories)

Inputs

• Assumption to test (required, free text)
• Optional: design/concept.md Section 8 (Riskiest Assumption) for context

Outputs

• prototypes/<name>/ — code
• prototypes/<name>/REPORT.md

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Phase 1: Frame the Question

If no argument was passed, ask:

• Prompt: "What assumption are you testing?"
• Free text — capture as kebab-case for the prototype name.

The framing matters. Use AskUserQuestion:

• Prompt: "Re-frame the assumption as a yes/no question. Pick or write:"
• Options: derived from the input — e.g., for "people will tap during a session":
  • Q: Can users complete the core action in <3 seconds while doing something else?
  • Q: Does the gesture work mid-activity without misfires?
  • Custom (free text)

The question becomes the prototype's success criterion.

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Phase 2: Define Success / Fail Criteria

Use AskUserQuestion:

• "What evidence would prove yes?" — free text
• "What evidence would prove no?" — free text