Riff

What it does

When your agent uses it

• User says explore options
• Give me variations
• Brainstorm approaches
• Wants to see multiple interpretations of a concept

Example prompts

• “explore options”
• “give me variations”
• “riff on this”
• “/riff”

Requirements

• Pre-approved tools (allowed-tools): Read, Write, Bash, Task, Glob, AskUserQuestion

Workflow steps

7 steps, taken from the step headings in SKILL.md.

1. 1Gather ALL Requirements Upfront
2. 2Create Riff Directories
3. 3Generate Riffs in Parallel
4. 4Assemble HTML
5. 5Evaluate & Rank
6. 6Generate Gallery
7. 7Present Results

What it can do on your machine

Read from SKILL.md and the folder at commit 5baf8a2. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves these tools, so the agent can use them without asking each time:

  • Read
  • Write
  • Bash
  • Task
  • Glob
  • AskUserQuestion

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Shell commands in SKILL.md call:

  • bun
  • claude

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  No URLs in SKILL.md.

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Riff loads about 2k tokens when it runs. Until then it costs about 74 tokens; SKILL.md has 453 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~74

When it runs · the whole SKILL.md, loaded when a task matches

~2k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

• NotePre-approves every shell command (allowed-tools: Bash)SKILL.md

  allowed-tools: Read, Write, Bash, Task, Glob, AskUserQuestion

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from popmechanic/VibesOS at commit 5baf8a2, republished under its MIT licence (© popmechanic). 453 words, ~2,034 tokens.

name

riff

description

Self-contained parallel generator — invoke directly, do not decompose. Generates 3-10 app variations in parallel for comparing ideas. Use when user says "explore options", "give me variations", "riff on this", "brainstorm approaches", or wants to see multiple interpretations of a concept.

allowed-tools

Read, Write, Bash, Task, Glob, AskUserQuestion

argument-hint

[prompt]

license

MIT

metadata.author

Marcus Estes

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Question 1: "What kind of app do you want to explore? (broad/loose is fine)"
Header: "Theme"
Options: User enters via "Other"

Question 2: "Describe the visual style - colors, mood, aesthetic"
Header: "Visual"
Options: ["Warm sunset tones", "Clean minimal white", "Neon cyberpunk", "Other (describe)"]

Question 3: "How many variations should I generate?"
Header: "Count"
Options: ["3 (recommended)", "5", "7", "10"]

mkdir -p riff-1 riff-2 riff-3 ...

VIBES_ROOT="${CLAUDE_PLUGIN_ROOT:-$(dirname "$(dirname "${CLAUDE_SKILL_DIR}")")}"
# For each N from 1 to ${count}:
bun "$VIBES_ROOT/scripts/generate-riff.js" "${prompt}" N riff-N/app.jsx "${visual}" &

# Then wait for all
wait
echo "All ${count} riffs generated!"

VIBES_ROOT="${CLAUDE_PLUGIN_ROOT:-$(dirname "$(dirname "${CLAUDE_SKILL_DIR}")")}"
bun "$VIBES_ROOT/scripts/generate-riff.js" "productivity apps" 1 riff-1/app.jsx "warm sunset oranges and soft creams" &
bun "$VIBES_ROOT/scripts/generate-riff.js" "productivity apps" 2 riff-2/app.jsx "warm sunset oranges and soft creams" &
bun "$VIBES_ROOT/scripts/generate-riff.js" "productivity apps" 3 riff-3/app.jsx "warm sunset oranges and soft creams" &
wait

VIBES_ROOT="${CLAUDE_PLUGIN_ROOT:-$(dirname "$(dirname "${CLAUDE_SKILL_DIR}")")}"
bun "$VIBES_ROOT/scripts/assemble-all.js" riff-1 riff-2 riff-3 ...

# Read pitch files - contains reasoning about theme, colors, functionality
cat riff-*/pitch.md

# Also read BUSINESS comments for app names (just first 10 lines of each)
head -10 riff-*/app.jsx

# Riff Rankings: [Theme]

## Summary

| Rank | App Name | Score | Best For |
|------|----------|-------|----------|
| 1 | [Name] | XX/50 | [one-liner] |
| 2 | [Name] | XX/50 | [one-liner] |
| ... | ... | ... | ... |

## Detailed Scores

### #1: [App Name] (riff-N)
| Criterion | Score | Notes |
|-----------|-------|-------|
| Originality | X/10 | [Why unique or derivative] |
| Market Potential | X/10 | [Target audience size, demand] |
| Feasibility | X/10 | [Technical complexity, time to build] |
| Monetization | X/10 | [Revenue model viability] |
| Wow Factor | X/10 | [First impression, engagement] |
| **Total** | **XX/50** | |

[Repeat for each riff]

## Recommendations

- **Best for solo founder:** [riff-N] - [reason]
- **Fastest to ship:** [riff-N] - [reason]
- **Most innovative:** [riff-N] - [reason]
- **Best monetization:** [riff-N] - [reason]

Generated ${count} riffs for "${prompt}":
#1: riff-X - App Name (XX/50)
#2: riff-Y - App Name (XX/50)
...

Open index.html for gallery, or browse riff-1/, riff-2/, etc.

Question: "You have ${count} variations ranked. What would you like to do?"
Header: "Next"
Options:
- Label: "Develop the #1 ranked app"
  Description: "Take the top-ranked variation and continue building it. I'll copy riff-1/app.jsx to your working directory so you can iterate with the full vibes feature set - add functionality, refine the design, make it yours."

- Label: "Let me pick a different one"
  Description: "The rankings are just my analysis - you might see something special in another variation. Tell me which riff number speaks to you and I'll set it up for development."

- Label: "Turn winner into SaaS (/sell)"
  Description: "Ready to monetize the best one? Sell adds authentication via Pocket ID with passkeys, subscription billing, and multi-tenant database isolation. Each customer gets their own subdomain with their own data."

- Label: "Deploy a riff as demo (/cloudflare)"
  Description: "Want to share one quickly? Deploy puts any variation live on Cloudflare Workers within minutes. Great for getting feedback before committing to further development."

- Label: "I'm done for now"
  Description: "Wrap up this session. All riffs are saved in riff-1/, riff-2/, etc. - browse them locally or come back later to continue."

© popmechanic, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 3 other files in skills/riff of popmechanic/VibesOS.

• SKILL.md
• defaults/style-prompt.txt
• template.delta.html
• templates/index.html

Open the folder on GitHubat commit 5baf8a2