# 🔗 API Reference Dynamic CSS generation API for Anthropic Fonts CDN. ## Overview The Anthropic Fonts API generates custom CSS on-demand based on query parameters. Load only the fonts and weights you need. --- ## Base URL ``` https://cdn.jsdelivr.net/gh/devchauhann/fonts@v1.1.0/cdn/api ``` For local development: ``` http://localhost:3000/api ``` --- ## Endpoints ### GET /css Generate dynamic CSS for specified fonts and weights. #### Parameters | Parameter | Type | Required | Example | Description | |-----------|------|----------|---------|-------------| | `family` | string | Yes | `AnthropicSans` | Font family name | | `weights` | string | Yes | `400;700` | Semicolon-separated weights | #### Font Families - `AnthropicSans` (or `sans`) - `AnthropicSerif` (or `serif`) - `AnthropicMono` (or `mono`) #### Valid Weights - `AnthropicSans`: 300, 400, 500, 600, 700, 800, 900 - `AnthropicSerif`: 300, 400, 500, 600, 700, 800, 900 - `AnthropicMono`: 400 #### Examples ##### Basic Request ```bash curl "https://cdn.jsdelivr.net/gh/devchauhann/fonts@v1.1.0/cdn/api/css?family=AnthropicSans&weights=400;700" ``` ##### Multiple Weights ```bash curl "https://cdn.jsdelivr.net/gh/devchauhann/fonts@v1.1.0/cdn/api/css?family=AnthropicSans&weights=300;400;500;700" ``` ##### Serif Font ```bash curl "https://cdn.jsdelivr.net/gh/devchauhann/fonts@v1.1.0/cdn/api/css?family=AnthropicSerif&weights=400;700" ``` ##### Short Name ```bash curl "https://cdn.jsdelivr.net/gh/devchauhann/fonts@v1.1.0/cdn/api/css?family=sans&weights=400" ``` --- ## Response Format ### Success Response (200) **Content-Type:** `text/css; charset=utf-8` ```css /* Anthropic Fonts - Dynamic CSS API */ /* Family: Anthropic Sans, Weights: 400,700 */ /* Generated: 2026-04-01T12:00:00.000Z */ @font-face { font-family: 'Anthropic Sans'; src: url('/v1/fonts/AnthropicSans@400.woff2') format('woff2'); font-weight: 400; font-style: normal; font-display: swap; unicode-range: U+0000-00FF, U+0131, U+0152-0153, ...; } @font-face { font-family: 'Anthropic Sans'; src: url('/v1/fonts/AnthropicSans@700.woff2') format('woff2'); font-weight: 700; font-style: normal; font-display: swap; unicode-range: U+0000-00FF, U+0131, U+0152-0153, ...; } ``` ### Error Responses #### 400 - Bad Request ```json { "error": "Font not found", "available": ["AnthropicSans", "AnthropicSerif", "AnthropicMono"] } ``` #### 400 - Invalid Weights ```json { "error": "Invalid weights parameter" } ``` #### 500 - Server Error ```json { "error": "Internal server error" } ``` --- ## Caching All responses are cached aggressively: ``` Cache-Control: public, max-age=31536000, immutable ``` This caches CSS for **1 year** safely because: - URLs are versioned in the CDN path - Query parameters are permanent - Content never changes --- ## Usage Examples ### HTML ```html ``` ### CSS ```css @import url('https://cdn.jsdelivr.net/gh/devchauhann/fonts@v1.1.0/cdn/api/css?family=AnthropicSans&weights=400;700'); body { font-family: 'Anthropic Sans', sans-serif; } ``` ### JavaScript ```javascript const fontUrl = new URL('https://cdn.jsdelivr.net/gh/devchauhann/fonts@v1.1.0/cdn/api/css'); fontUrl.searchParams.set('family', 'AnthropicSans'); fontUrl.searchParams.set('weights', '400;700'); const link = document.createElement('link'); link.rel = 'stylesheet'; link.href = fontUrl.toString(); document.head.appendChild(link); ``` ### React ```jsx export function FontLoader() { useEffect(() => { const params = new URLSearchParams({ family: 'AnthropicSans', weights: '400;700' }); const link = document.createElement('link'); link.rel = 'stylesheet'; link.href = `https://cdn.jsdelivr.net/gh/devchauhann/fonts@v1.1.0/cdn/api/css?${params}`; document.head.appendChild(link); }, []); return

Hello

; } ``` --- ## Alternative Endpoint: /fonts Legacy format endpoint (maps to `/css`): ```bash # Query format: FontName@weight1;weight2 curl "https://cdn.jsdelivr.net/gh/devchauhann/fonts@v1.1.0/cdn/api/fonts?query=AnthropicSans@400;700" ``` --- ## Metadata Endpoint ### GET /v1/metadata Get font family information and available variants. **Response:** ```json { "version": "1.0.0", "updated": "2026-04-01T06:04:30.100Z", "fonts": [ { "family": "Anthropic Sans", "category": "sans-serif", "variants": [ { "weight": 300, "style": "normal", "file": "AnthropicSans@300.woff2", "unicodeRanges": { "latin": "U+0000-00FF, ...", "latin-ext": "U+0100-024F, ..." } }, ... ], "unicodeRange": "U+0000-00FF, U+0131, ..." }, ... ] } ``` **Usage:** ```javascript fetch('https://cdn.jsdelivr.net/gh/devchauhann/fonts@v1.1.0/cdn/v1/metadata') .then(r => r.json()) .then(meta => { console.log('Available fonts:', meta.fonts); }); ``` --- ## Static Endpoints ### All Fonts CSS ``` GET /v1/css/all.css ``` Includes all font families and weights. ### Individual Font CSS ``` GET /v1/css/anthropicsans.css GET /v1/css/anthropicserif.css GET /v1/css/anthropicmono.css ``` Individual font family CSS files. ### Minified CSS ``` GET /v1/css/all.min.css ``` Minified version of all.css (saves ~60%). ### Font Files ``` GET /v1/fonts/AnthropicSans@400.woff2 GET /v1/fonts/AnthropicSans@700.woff2 GET /v1/fonts/AnthropicSerif@400.woff2 ... (all weights available) ``` --- ## Health Check ### GET /health Check if API is running. **Response:** ```json { "status": "ok", "timestamp": "2026-04-01T12:00:00.000Z" } ``` --- ## Performance Tips ### 1. Load Only Needed Weights ```html ``` ### 2. Use Preconnect ```html ``` ### 3. Cache Aggressively Responses include `immutable` cache header - safe to cache forever. ### 4. Combine with Preload ```html ``` --- ## API Conventions ### URL Format ``` https://cdn.jsdelivr.net/gh/devchauhann/fonts@v1.1.0/cdn/api/css ?family=AnthropicSans ← Font family &weights=400;700 ← Semicolon-separated weights ``` ### Allowed Characters - Font names: Alphanumeric (AnthropicSans, sans, serif) - Weights: Numbers 100-900 separated by semicolons (300;400;700) ### Query Parameter Validation - Missing `family`: Returns 400 error - Invalid `family`: Returns 400 with available list - Invalid `weights`: Returns 400 error - Missing `weights`: Defaults to 400 --- ## Rate Limiting The API respects jsDelivr's rate limits: - **Per IP:** 1000 requests per hour - **Per file:** 5000 requests per minute For most use cases, static CDN URLs are cached, so minimal requests. --- ## CORS Headers All API responses include: ``` Access-Control-Allow-Origin: * Access-Control-Allow-Methods: GET, OPTIONS Access-Control-Allow-Headers: Content-Type ``` Safe for cross-origin requests from any domain. --- ## Content Negotiation ### Content-Type API responds with appropriate content types: - **CSS endpoint:** `text/css; charset=utf-8` - **JSON endpoints:** `application/json` - **Font files:** `application/font-woff2` ### Accept Header The API ignores Accept headers and serves based on endpoint: ```bash # Always returns CSS regardless of Accept header GET /api/css?family=AnthropicSans&weights=400 # Always returns JSON GET /v1/metadata ``` --- ## Versioning API versions in CDN path: ``` /v1/css/... ← Version 1 CSS /v1/fonts/... ← Version 1 fonts /api/css?... ← Latest API ``` To lock to specific version, use Git tags: ``` https://cdn.jsdelivr.net/gh/devchauhann/fonts@v1.0.0/cdn/api/css?... ``` --- ## Changelog ### v1.0.0 (Current) - ✅ Dynamic CSS generation - ✅ Multiple weights support - ✅ All three font families (Sans, Serif, Mono) - ✅ Metadata endpoint - ✅ CORS support - ✅ Aggressive caching ### Planned Features - [ ] Font subsetting by character range - [ ] Italic style support - [ ] Variable font format (single file, any weight) - [ ] WebP image format for fallback - [ ] Usage analytics --- ## Support & Issues Report issues or request features: - GitHub Issues: https://github.com/devchauhann/fonts/issues - Documentation: See [USAGE.md](./USAGE.md) and [PERFORMANCE.md](./PERFORMANCE.md) --- ## License API and fonts are provided as-is. See [LICENSE](../LICENSE) file.