Write a VibeFuse Skill — from blank SKILL.md to marketplace listing

What a skill is (and is not)

Skills are instructions, not code. When a user invokes /release-notes-writer, clicks it in the rail, or simply asks for something that matches the description, the agent loads the full SKILL.md into context and follows it — using whatever tools it already has (terminal, browser, MCP servers, file reads). The same format is used by Claude Code, Codex, and Cursor, so a skill you write for VibeFuse also works in those agents.

Format

Folder with SKILL.md (+ optional references)

Where it lives

C:\vibefuse\skills\<slug>\

Triggered by

Rail click · /slug · description match

Limits

200 KB markdown per skill

Prerequisites

• VibeFuse for Windows signed in with your VF- key, and a working AI provider in Settings → Agent (any provider — OpenAI, Ollama, Gemini, Groq, OpenRouter …).
• A text editor, or just the Vibe Agent widget (it can write the files for you).
• A task you have done by hand at least twice. Skills that encode real repetition are the ones people save.
• To sell (optional): seller profile + Stripe Connect.

Package anatomy

One required file. The folder name is the slug users type after /.

Keep SKILL.md short and put depth in references/. The agent reads the main file every time the skill fires; it reads references only when your instructions tell it to (read_skill_file). Progressive disclosure keeps context small and answers fast.

---
name: canvas-layout-helper
description: Use when arranging VibeFuse canvas widgets into rows, columns, or a focused layout.
version: 1.0.0
author: fuseintelligence
kind: marketplace
---

# Canvas layout helper

Tile terminals on the left and browsers on the right.
Call layout_widget with arrange=row when the user says “clean up the canvas.”

Step 1 — Frontmatter

The block between the two --- lines is YAML-style key: value pairs. VibeFuse reads four keys; other agents ignore what they do not know.

---
name: release-notes-writer
description: Use when the user asks for release notes, a changelog entry, or a "what's new" summary from recent commits or a diff.
version: 1.0.0
category: workflow
---

Step 2 — Writing the body

The body is plain markdown. A structure that works for almost every skill:

1. 01
   Title + one-line purpose

   An # H1 and a sentence restating what the skill produces. This is what a human sees in the rail details overlay.

2. 02
   ## When to use

   Bullet the trigger situations and phrases. Include a “do not use for …” line if the skill is easily confused with another.

3. 03
   ## Inputs

   What the agent needs and how to get it inside VibeFuse: which tool to call (read_terminal, get_browser_html, read_skill_file, an MCP tool), and what to ask the user if something is missing.

4. 04
   ## Steps

   A numbered procedure. Imperative voice, one action per step, decisions written as “if X then Y”. This is the part that makes results consistent.

5. 05
   ## Output format

   Show the exact shape you want back — a fenced example beats a paragraph of description.

6. 06
   ## Guardrails

   What the agent must never do (invent data, run destructive commands, exceed a length). Short, absolute sentences.

• Aim for 80–300 lines. If it is longer, move detail into references/ and point to it.
• Name VibeFuse tools when relevant (layout_widget, create_terminal, web_search, hyperframes_render) — the agent has them and will use them.
• Prefer examples over adjectives. One good/bad pair teaches more than “be concise”.
• Avoid provider-specific syntax. The same file runs under Claude, Codex, Gemini, and Cursor.

Complete example — release-notes-writer

Copy this into C:\vibefuse\skills\release-notes-writer\SKILL.md. It follows the structure above and references one supporting file.

---
name: release-notes-writer
description: Use when the user asks for release notes, a changelog entry, or a "what's new" summary from recent commits or a diff. Produces grouped, user-facing notes.
version: 1.0.0
category: workflow
---

# Release notes writer

Turn raw commits, PR titles, or a diff into release notes a customer can read.

## When to use
- The user says "write release notes", "changelog", "what changed", or "what's new".
- A version bump is happening and the notes are missing.

## Inputs
1. Ask which range to cover if it is not obvious (tag, date, or "since last release").
2. Read the commits or diff from the workspace. In VibeFuse, use `read_terminal` after running
   `git log --oneline <from>..<to>` in an open terminal, or read `CHANGELOG.md` with `read_skill_file`
   if the project keeps one.

## Steps
1. Drop noise: merge commits, formatting-only changes, dependency bumps (mention those once, at the end).
2. Group what remains under **Added**, **Changed**, **Fixed**, **Removed**.
3. Rewrite each item for a user, not a developer: what they can now do, not which file moved.
4. Lead with the single most valuable change. Keep bullets to one line.
5. Add a **Breaking changes** section only if something requires user action, with the exact steps.

## Output format
```markdown
## v1.4.0 — 2026-09-11

### Added
- Quote Board widget remembers favorites between sessions.

### Fixed
- Focus Timer no longer drifts after the laptop sleeps.

### Dependencies
- Piper 1.3.
```

## Guardrails
- Never invent a change that is not in the source material.
- If the range is empty, say so and stop.
- Keep the whole document under 300 words unless the user asks for more.

See `references/style.md` for tone examples.

Two marketplace skills to read as reference: Canvas layout helper (tool-centric, tiny) and /Loop (behavioral, runs until a goal is met).

Step 3 — Supporting files

Anything under references/, scripts/, or assets/ ships with the skill. The agent reads them with read_skill_file when your instructions say so.

# Tone guide

Good:  "Search now matches partial widget names."
Bad:   "Refactored SearchIndex.ts to use fuzzy matcher."

Good:  "Fixed a crash when closing a session with an unsaved note."
Bad:   "Handle null ref in SessionManager.dispose()."

# scripts/collect-commits.ps1 — the skill can tell the agent to run this in a Terminal widget
param([string]$From = (git describe --tags --abbrev=0), [string]$To = "HEAD")
git log --no-merges --pretty=format:"%s" "$From..$To"

• Reference files are markdown/text. Keep each under a few hundred lines; the agent pays for every token it reads.
• Scripts are run by the user's agent in the user's terminal. Never include anything destructive or network-writing without saying so in the skill.
• Web publishing currently uploads SKILL.md; supporting files travel with the local folder and with desktop publishing. If a reference is essential, inline its key points in SKILL.md.

Shortcut — let Vibe Agent write it

Open a Vibe Agent widget and describe the skill. It calls create_skill (name, description, body, files) and the Skills rail refreshes the moment it returns. Use update_skill to iterate.

Create a skill named release-notes-writer.
Description: Use when the user asks for release notes or a changelog from commits or a diff.
Body: group changes under Added / Changed / Fixed / Removed, rewrite for end users,
lead with the most valuable change, add Breaking changes only when action is required.
Also add references/style.md with three good/bad tone examples.

Before you write a docs skill — check Skill Seekers

If your skill is “everything about React / Godot / Blender / Unity / Claude Code”, someone has probably already scraped those docs. Connect Settings → Local Servers → Skill Seekers and ask Vibe Agent “is there already a skill for …”. It runs skill-seekers-lookup and lists presets you can install instead of duplicating. If nothing matches, Skill Seekers can scrape a docs site and package it as a SKILL.md folder you then refine and publish.

Details: Skill Seekers in the VibeFuse docs.

Step 4 — Test in VibeFuse

1. 01
   Drop the folder in place

   C:\vibefuse\skills\release-notes-writer\SKILL.md. Open Settings → Skills (or wait a moment) — it appears with a Local badge and shows up in the left-rail Skills section.

2. 02
   Read it back

   Click the skill in the rail to open the details overlay. If name/description look wrong, the frontmatter has a typo (missing colon, stray quotes, Windows BOM).

3. 03
   Fire it three ways

   Type /release-notes-writer in a Vibe Agent widget · click it in the rail · ask naturally (“write release notes for the last tag”). The third one tests your description.

4. 04
   Try it in a CLI agent too

   Open a Claude or Codex widget in the same session and ask the same thing. Skills in C:\vibefuse\skills are standard Agent Skills, so they load there as well.

5. 05
   Tighten

   Where the output drifted, add a step or an example. Where the agent asked an unnecessary question, add the answer to Inputs. Repeat until three runs in a row are right.

Step 5 — Publish

Two paths lead to the same listing. Both stamp your profile name as the author and give the skill an id like com.yourname.release-notes-writer.

On publish the server re-wraps your markdown with canonical frontmatter (name = slug, your description) and generates manifest.json. Buyers who save the skill get both files in C:\vibefuse\skills\<slug> on their next launch.

Step 6 — Polish the listing

Your page lives at /marketplace/skill/<slug> with owner, version, saves, the markdown preview, and Save to VibeFuse. It also rotates through the marketplace pulse under Trending skills as saves come in.

Step 7 — Free or paid

See also: Sell AI skills · How to publish a VibeFuse skill.

Step 8 — Ship an update

• Edit SKILL.md, bump version, then Update listing in Settings → Marketplace — or edit and Publish again in Account → Marketplace Settings.
• The slug and id stay fixed; saves, views, and price carry over.
• Users receive the new file on their next library sync (app launch or closing the in-app marketplace).
• Unpublish hides the listing without deleting it; installed copies keep working.

Pre-publish checklist

• Frontmatter has name (kebab-case = folder name) and a one-line description starting with “Use when …”
• Body has When to use · Inputs · Steps · Output format · Guardrails
• An example of the expected output is included
• Fired successfully three times in a row via /slug, rail click, and natural language
• Also tested in at least one CLI agent widget (Claude / Codex / Cursor)
• No secrets, no destructive commands without explicit warning, nothing provider-specific
• Under 200 KB; long material moved to references/
• Category chosen; buyer-facing short description written; price decided

Troubleshooting

FAQ

Next guides

Related: Agent Skills in VibeFuse · Skill Seekers · Skill catalog