Prototype

--- name: prototype type: workflow description: "Executes a rapid prototyping workflow that skips normal standards to quickly validate a product concept or core mechanic, producing throwaway code and a prototype report. Use when the user wants to quickly test an idea or mentions prototyping, proof of concept, or MVP spike." argument-hint: "[concept-description]" user-invocable: true allowed-tools: Read, Glob, Grep, Write, Edit, Bash effort: 3 when_to_use: "Use when the user wants to quickly validate a product concept or core mechanic before committing to full implementation, or mentions prototyping, proof of concept, or MVP spike."

When this skill is invoked:

1. Read the concept description from the argument. Identify the core question this prototype must answer. If the concept is vague, state the question explicitly before proceeding.

2. Read CLAUDE.md for project context and the current tech stack. Understand what engine, language, and frameworks are in use so the prototype is built with compatible tooling.

3. Create a prototype plan: Define in 3-5 bullet points what the minimum viable prototype looks like. What is the core question? What is the absolute minimum code needed to answer it? What can be skipped?

4. Create the prototype directory: prototypes/[concept-name]/ where [concept-name] is a short, kebab-case identifier derived from the concept.

5. Implement the prototype in the isolated directory. Every file must begin with:

   // PROTOTYPE - NOT FOR PRODUCTION
   // Question: [Core question being tested]
   // Date: [Current date]
   

   Standards are intentionally relaxed:

   • Hardcode values freely
   • Use placeholder assets
   • Skip error handling
   • Use the simplest approach that works
   • Copy code rather than importing from production

6. Test the concept: Run the prototype. Observe behavior. Collect any measurable data (frame times, interaction counts, feel assessments).

7. Generate the Prototype Report and save it to prototypes/[concept-name]/REPORT.md:

## Prototype Report: [Concept Name]

### Hypothesis
[What we expected to be true -- the question we set out to answer]

### Approach
[What we built, how long it took, what shortcuts we took]

### Result
[What actually happened -- specific observations, not opinions]

### Metrics
[Any measurable data collected during testing]
- Frame time: [if relevant]
- Feel assessment: [subjective but specific -- "response felt sluggish at
  200ms delay" not "felt bad"]
- User action counts: [if relevant]
- Iteration count: [how many attempts to get it working]

### Recommendation: [PROCEED / PIVOT / KILL]

[One paragraph explaining the recommendation with evidence]

### If Proceeding
[What needs to change for a production-quality implementation]
- Architecture requirements
- Performance targets
- Scope adjustments from the original design
- Estimated production effort

### If Pivoting
[What alternative direction the results suggest]

### If Killing
[Why this concept does not work and what we should do instead]

### Lessons Learned
[Discoveries that affect other systems or future work]

8. Output a summary to the user with: the core question, the result, and the recommendation. Link to the full report at prototypes/[concept-name]/REPORT.md.

Important Constraints

• Prototype code must NEVER import from production source files
• Production code must NEVER import from prototype directories
• If the recommendation is PROCEED, the production implementation must be written from scratch -- prototype code is not refactored into production
• Total prototype effort should be timeboxed to 1-3 days equivalent of work
• If the prototype scope starts growing, stop and reassess whether the question can be simplified

Protocol

• Question: Reads concept from argument; if vague, states the core hypothesis explicitly before proceeding
• Options: Skip
• Decision: Prototype plan (3-5 bullets) shown and confirmed before implementation begins
• Draft: REPORT.md summary shown before saving
• Approval: "May I create prototypes/[concept-name]/ and implement the prototype?"

Output

Deliver exactly:

• Prototype code in prototypes/[concept-name]/ (throwaway — never imported by src/)
• Report saved to prototypes/[concept-name]/REPORT.md
• Hypothesis verdict: VALIDATED / INVALIDATED / INCONCLUSIVE
• Recommendation: PROCEED (rewrite from scratch in src/) / PIVOT / ABANDON