UI Package

What it does

When your agent uses it

• Creating a UI package
• Working inside one
• In an app that consumes one: adding
• Reviewing a widget

Example prompts

• “write its tests”
• “only pull in what I use”
• “create a ui package”
• “/ui-package”

Requirements

• Pre-approved tools (allowed-tools): Read, Glob, Grep, Edit, Write, mcp__very-good-cli__create

What it can do on your machine

Read from SKILL.md and the folder at commit 496a3c6. 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
  • Glob
  • Grep
  • Edit
  • Write
  • mcp__very-good-cli__create

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Shell commands in SKILL.md call:

  • flutter

  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

UI Package loads about 2.2k tokens when it runs. Until then it costs about 220 tokens; SKILL.md has 742 words of instructions outside code blocks.

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

~220

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

~2.2k

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

• WarningTells the agent its actions are pre-authorized / not to stop for confirmationSKILL.md:34

  onse. Do not stop at the objection, and do not ask permission to do it the documented way

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 VeryGoodOpenSource/vgv-ai-flutter-plugin at commit 496a3c6, republished under its MIT licence (© VeryGoodOpenSource). 742 words, ~2,242 tokens.

name

ui-package

description

Best practices for building a Flutter UI package on Material: custom components, ThemeExtension theming, consistent APIs, widget tests, app_ui_package scaffolding. Use when creating a UI package, working inside one, or in an app that consumes one: adding or reviewing a widget, wiring design tokens, exporting through the barrel file, or writing tests for a widget under lib/src/widgets, which pump through the package's pumpApp helper, so prefer this over general test guidance even when the ask is only "write its tests". Also use it when asked to approve what this skill forbids: importing package:<name>/src/... per file, skipping the barrel to "only pull in what I use", or a parallel theme system. Triggers on any request naming a package of shared widgets and design tokens, such as "create a ui package", "add a design token", or "is it fine to import from src".

allowed-tools

Read, Glob, Grep, Edit, Write, mcp__very-good-cli__create

my_ui/
├── lib/
│   ├── my_ui.dart              # Barrel file — re-exports material.dart + all public API
│   └── src/
│       ├── theme/
│       │   ├── app_theme.dart        # AppTheme class with light/dark ThemeData builders
│       │   ├── app_colors.dart       # AppColors ThemeExtension for custom color tokens
│       │   ├── app_spacing.dart      # AppSpacing ThemeExtension for spacing tokens
│       │   └── app_text_styles.dart  # Optional: extra text styles beyond Material's TextTheme
│       ├── widgets/
│       │   ├── app_button.dart
│       │   ├── app_text_field.dart
│       │   ├── app_card.dart
│       │   └── ...
│       └── extensions/
│           └── build_context_extensions.dart  # context.appColors, context.appSpacing shortcuts
├── test/
│   ├── src/
│   │   ├── theme/
│   │   │   └── app_theme_test.dart
│   │   └── widgets/
│   │       ├── app_button_test.dart
│   │       └── ...
│   └── helpers/
│       └── pump_app.dart         # Test helper wrapping widgets in MaterialApp + theme
├── widgetbook/                   # Widgetbook catalog submodule (sandbox + showcase)
│   └── ...
└── pubspec.yaml

© VeryGoodOpenSource, 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 2 other files in skills/ui-package of VeryGoodOpenSource/vgv-ai-flutter-plugin.

• SKILL.md
• agents/openai.yaml
• reference.md

Open the folder on GitHubat commit 496a3c6