--- name: favicon description: Generate a complete set of favicons from a source image and update HTML. Use when setting up favicons for a web project. argument-hint: [ path to source image ] title: favicon canonical_url: https://skilld.dev/gh/brianlovin/agent-config/favicon last_updated: 2026-09-26T13:20:29.000Z --- > Index of every page on this site: [llms.txt](https://skilld.dev/llms.txt) > **Skill from skilld.dev.** Follow the user's requested action. > If the user asked to fork this Skill, follow the fork workflow below. Do not execute the Skill instructions while copying it. > Otherwise, follow the instructions below for this session. You do not need to install anything. > > If the user asked to install this Skill, run `npx skilld install brianlovin/agent-config/favicon`. Install writes the Skill files into the project, so every session loads them. > > ## Fork workflow > > A fork creates an editable local Skill with its original author and licence. The request authorizes copying and local installation. > 1. Check `./skills/favicon`, the project lockfile, and selected Agent targets together. If the local directory or installed Skill exists, stop. Never overwrite an existing directory or Agent target. > 2. Read [source metadata](https://skilld.dev/api/v1/skills/brianlovin/agent-config/favicon) once. Use sourceUrl, sourceCommit, skillPath, sourceGone, and license. If the source is gone or its path is missing, stop. If license is null, read licence files at the source commit. > 3. Fetch only the source commit into a temporary Git repository. Do not clone full history. Derive repository_url from sourceUrl, including repository renames. If sourceCommit is absent, resolve the sourceUrl ref once. Set source_commit to that actual commit. Run these commands in one shell call: > > ```sh > git init --quiet "$temporary_dir" > git -C "$temporary_dir" fetch --quiet --depth=1 "$repository_url" "$source_commit" > git -C "$temporary_dir" checkout --quiet --detach FETCH_HEAD > ``` > > Read applicable licence declarations and notices at that commit. If copying is not permitted, report the restriction and stop. > 4. Inspect source entries together, then copy the directory containing skillPath into `./skills/favicon`. Use the user's path if selected. Keep the original SKILL.md, relative links, scripts, binary assets, and executable modes. Exclude .git metadata. Reject symlinks and paths outside the Skill directory. After checking entries, use cp -a where available. A regular source directory needs no custom copy script. Do not save this page wrapper as SKILL.md. > Preserve author credit, notices, and applicable licence files from repository or parent directories. Add PROVENANCE.md with the Skill page, source URL, actual commit, original path, and licence. Retain any existing PROVENANCE.md and record new provenance separately. Batch source inspection, copying, and provenance work where practical. > 5. In the project root, run `skilld install ./skills/favicon --mode copy --plain`. If skilld is unavailable, use `npx skilld install ./skills/favicon --mode copy --plain`. This known command needs no help lookup. Install does not support --json. Use detected Agent targets, or add --agent for the targets the user selected. Install the local path, never the upstream selector. If installation fails, preserve the local copy and report the exact failure. > 6. Confirm the local lockfile source and installed Agent copies once. Report the local path, actual commit, and Agent targets. After edits, reinstall the same local path. Upstream updates must not replace it. Do not publish or push unless the user asks. Generate a complete set of favicons from the source image at `$1` and update the project's HTML with the appropriate link tags. ## Prerequisites First, verify ImageMagick v7+ is installed by running: ```bash which magick ``` If not found, stop and instruct the user to install it: - **macOS**: `brew install imagemagick` - **Linux**: `sudo apt install imagemagick` ## Step 1: Validate Source Image 1. Verify the source image exists at the provided path: `$1` 2. Check the file extension is a supported format (PNG, JPG, JPEG, SVG, WEBP, GIF) 3. If the file doesn't exist or isn't a valid image format, report the error and stop Note whether the source is an SVG file - if so, it will also be copied as `favicon.svg`. ## Step 2: Detect Project Type and Static Assets Directory Detect the project type and determine where static assets should be placed. Check in this order: | Framework | Detection | Static Assets Directory | |-----------|-----------|------------------------| | **Rails** | `config/routes.rb` exists | `public/` | | **Next.js** | `next.config.*` exists | `public/` | | **Gatsby** | `gatsby-config.*` exists | `static/` | | **SvelteKit** | `svelte.config.*` exists | `static/` | | **Astro** | `astro.config.*` exists | `public/` | | **Hugo** | `hugo.toml` or `config.toml` with Hugo markers | `static/` | | **Jekyll** | `_config.yml` with Jekyll markers | Root directory (same as `index.html`) | | **Vite** | `vite.config.*` exists | `public/` | | **Create React App** | `package.json` has `react-scripts` dependency | `public/` | | **Vue CLI** | `vue.config.*` exists | `public/` | | **Angular** | `angular.json` exists | `src/assets/` | | **Eleventy** | `.eleventy.js` or `eleventy.config.*` exists | Check `_site` output or root | | **Static HTML** | `index.html` in root | Same directory as `index.html` | **Important**: If existing favicon files are found (e.g., `favicon.ico`, `apple-touch-icon.png`), use their location as the target directory regardless of framework detection. Report the detected project type and the static assets directory that will be used. **When in doubt, ask**: If you are not 100% confident about where static assets should be placed (e.g., ambiguous project structure, multiple potential locations, unfamiliar framework), use `AskUserQuestionTool` to confirm the target directory before proceeding. It's better to ask than to put files in the wrong place. ## Step 3: Determine App Name Find the app name from these sources (in priority order): 1. **Existing `site.webmanifest`** - Check the detected static assets directory for an existing manifest and extract the `name` field 2. **`package.json`** - Extract the `name` field if it exists 3. **Rails `config/application.rb`** - Extract the module name (e.g., `module MyApp` → "MyApp") 4. **Directory name** - Use the current working directory name as fallback Convert the name to title case if needed (e.g., "my-app" → "My App"). ## Step 4: Ensure Static Assets Directory Exists Check if the detected static assets directory exists. If not, create it. ## Step 5: Generate Favicon Files Run these ImageMagick commands to generate all favicon files. Replace `[STATIC_DIR]` with the detected static assets directory from Step 2. ### favicon.ico (multi-resolution: 16x16, 32x32, 48x48) ```bash magick "$1" \ \( -clone 0 -resize 16x16 \) \ \( -clone 0 -resize 32x32 \) \ \( -clone 0 -resize 48x48 \) \ -delete 0 -alpha on -background none \ [STATIC_DIR]/favicon.ico ``` ### favicon-96x96.png ```bash magick "$1" -resize 96x96 -background none -alpha on [STATIC_DIR]/favicon-96x96.png ``` ### apple-touch-icon.png (180x180) ```bash magick "$1" -resize 180x180 -background none -alpha on [STATIC_DIR]/apple-touch-icon.png ``` ### web-app-manifest-192x192.png ```bash magick "$1" -resize 192x192 -background none -alpha on [STATIC_DIR]/web-app-manifest-192x192.png ``` ### web-app-manifest-512x512.png ```bash magick "$1" -resize 512x512 -background none -alpha on [STATIC_DIR]/web-app-manifest-512x512.png ``` ### favicon.svg (only if source is SVG) If the source file has a `.svg` extension, copy it: ```bash cp "$1" [STATIC_DIR]/favicon.svg ``` ## Step 6: Create/Update site.webmanifest Create or update `[STATIC_DIR]/site.webmanifest` with this content (substitute the detected app name): ```json { "name": "[APP_NAME]", "short_name": "[APP_NAME]", "icons": [ { "src": "/web-app-manifest-192x192.png", "sizes": "192x192", "type": "image/png", "purpose": "maskable" }, { "src": "/web-app-manifest-512x512.png", "sizes": "512x512", "type": "image/png", "purpose": "maskable" } ], "theme_color": "#ffffff", "background_color": "#ffffff", "display": "standalone" } ``` If `site.webmanifest` already exists in the static directory, preserve the existing `theme_color`, `background_color`, and `display` values while updating the `name`, `short_name`, and `icons` array. ## Step 7: Update HTML/Layout Files Based on the detected project type, update the appropriate file. Adjust the `href` paths based on where the static assets directory is relative to the web root: - If static files are in `public/` or `static/` and served from root → use `/favicon.ico` - If static files are in `src/assets/` → use `/assets/favicon.ico` - If static files are in the same directory as HTML → use `./favicon.ico` or just `favicon.ico` ### For Rails Projects Edit `app/views/layouts/application.html.erb`. Find the `` section and add/replace favicon-related tags with: ```html ``` **Important**: - If the source was NOT an SVG, omit the `` line - Remove any existing `` section, after `` and `` if present ### For Next.js Projects Edit the detected layout file (`app/layout.tsx` or `src/app/layout.tsx`). Update or add the `metadata` export to include icons configuration: ```typescript export const metadata: Metadata = { // ... keep existing metadata fields icons: { icon: [ { url: '/favicon.ico' }, { url: '/favicon-96x96.png', sizes: '96x96', type: 'image/png' }, { url: '/favicon.svg', type: 'image/svg+xml' }, ], shortcut: '/favicon.ico', apple: '/apple-touch-icon.png', }, manifest: '/site.webmanifest', appleWebApp: { title: '[APP_NAME]', }, }; ``` **Important**: - If the source was NOT an SVG, omit the `{ url: '/favicon.svg', type: 'image/svg+xml' }` entry from the icon array - If metadata export doesn't exist, create it with just the icons-related fields - If metadata export exists, merge the icons configuration with existing fields ### For Static HTML Projects Edit the detected `index.html` file. Add the same HTML as Rails within the `` section. ### If No Project Detected Skip HTML updates and inform the user they need to manually add the following to their HTML ``: ```html ``` ## Step 8: Summary Report completion with: - Detected project type and framework - Static assets directory used - List of files generated - App name used in manifest and HTML - Layout file updated (or note if manual update is needed) - Note if any existing files were overwritten ## Error Handling - If ImageMagick is not installed, provide installation instructions and stop - If the source image doesn't exist, report the exact path that was tried and stop - If ImageMagick commands fail, report the specific error message - If the layout file cannot be found for HTML updates, generate files anyway and instruct on manual HTML addition