elysiajs-cdn-cache

A TypeScript-first CDN caching plugin for Elysia that simplifies cache control header management. No more manually setting cache headers - this plugin provides a clean, type-safe API for managing Cache-Control directives with support for multiple header types.

✨ Features

• 🎯 Type-safe Cache-Control management - Full TypeScript support for all cache directives
• 🔧 Fluent API - Chainable methods for easy cache configuration
• 📝 Auto-parsing - Parse existing Cache-Control headers from requests
• 🌐 Multi-header support - Support for Cache-Control, CDN-Cache-Control, and Vercel-CDN-Cache-Control
• ⚡ Zero dependencies - Lightweight with only Elysia as a peer dependency
• 🛡️ Production ready - Supports all standard cache directives

📦 Installation

# Using npm
npm install elysiajs-cdn-cache

# Using bun
bun add elysiajs-cdn-cache

# Using yarn
yarn add elysiajs-cdn-cache

# Using pnpm
pnpm add elysiajs-cdn-cache

🚀 Quick Start

import { Elysia } from "elysia";
import { cacheControl, CacheControl } from "elysiajs-cdn-cache";

const app = new Elysia()
  .use(cacheControl("Cache-Control"))
  .get("/", ({ cacheControl }) => {
    // Set cache headers
    cacheControl.set(
      "Cache-Control",
      new CacheControl()
        .set("public", true)
        .set("max-age", 3600)
        .set("s-maxage", 7200)
    );

    return { message: "Cached response!", timestamp: Date.now() };
  })
  .listen(3000);

📖 API Reference

Plugin Setup

import { cacheControl } from "elysiajs-cdn-cache";

// Default header (Cache-Control)
app.use(cacheControl());

// Single header
app.use(cacheControl("CDN-Cache-Control"));

// Multiple headers for different CDN layers
app.use(
  cacheControl(
    "Cache-Control", // Browser cache
    "CDN-Cache-Control", // General CDN cache
    "Vercel-CDN-Cache-Control" // Vercel-specific cache
  )
);

CacheControl Class

The CacheControl class provides a fluent API for building cache directives:

Constructor

// Create empty instance
const cache = new CacheControl();

// Parse from existing header string
const cache = new CacheControl("public, max-age=3600, s-maxage=7200");

Cache Directive Methods

const cache = new CacheControl()
  // Time-based directives
  .set("max-age", 3600) // max-age=3600
  .set("s-maxage", 7200) // s-maxage=7200
  .set("stale-while-revalidate", 60) // stale-while-revalidate=60
  .set("stale-if-error", 300) // stale-if-error=300

  // Boolean directives
  .set("public", true) // public
  .set("private", true) // private
  .set("no-cache", true) // no-cache
  .set("no-store", true) // no-store
  .set("must-revalidate", true) // must-revalidate
  .set("proxy-revalidate", true) // proxy-revalidate
  .set("immutable", true) // immutable
  .set("no-transform", true) // no-transform
  .set("must-understand", true); // must-understand

Serialization

const cache = new CacheControl().set("public", true).set("max-age", 3600);

console.log(cache.toString()); // "public, max-age=3600"

Route Handler Usage

app.get("/api/data", ({ cacheControl }) => {
  // Read incoming cache headers
  const incomingCache = cacheControl.get("Cache-Control");
  console.log("Incoming cache:", incomingCache.toString());

  // Set response cache headers
  cacheControl.set(
    "Cache-Control",
    new CacheControl().set("public", true).set("max-age", 300) // Browser cache: 5 minutes
  );

  // Set CDN-specific caching
  cacheControl.set(
    "CDN-Cache-Control",
    new CacheControl().set("public", true).set("s-maxage", 3600) // CDN cache: 1 hour
  );

  return { timestamp: Date.now() };
});

🔧 Common Patterns

Static Assets

app.get("/assets/*", ({ cacheControl }) => {
  cacheControl.set(
    "Cache-Control",
    new CacheControl()
      .set("public", true)
      .set("max-age", 31536000) // 1 year
      .set("immutable", true)
  );

  // Serve static file...
});

API Responses with CDN

app.get("/api/posts", ({ cacheControl }) => {
  cacheControl.set(
    "Cache-Control",
    new CacheControl()
      .set("public", true)
      .set("max-age", 60) // Browser: 1 minute
      .set("stale-while-revalidate", 300) // Allow stale for 5 minutes
  );

  cacheControl.set(
    "Vercel-CDN-Cache-Control",
    new CacheControl().set("public", true).set("s-maxage", 3600) // Vercel CDN: 1 hour
  );

  return await getPosts();
});

Private/Authenticated Content

app.get("/user/profile", ({ cacheControl }) => {
  cacheControl.set(
    "Cache-Control",
    new CacheControl()
      .set("private", true)
      .set("max-age", 300)
      .set("must-revalidate", true)
  );

  return await getUserProfile();
});

No Caching

app.get("/api/realtime", ({ cacheControl }) => {
  cacheControl.set(
    "Cache-Control",
    new CacheControl().set("no-store", true).set("no-cache", true)
  );

  return await getRealtimeData();
});

🌐 Multi-CDN Support

This plugin supports multiple cache control headers for complex CDN setups:

app.use(
  cacheControl(
    "Cache-Control", // Controls browser caching
    "CDN-Cache-Control", // Controls intermediate CDNs
    "Vercel-CDN-Cache-Control" // Controls Vercel's Edge Network
  )
);

app.get("/api/content", ({ cacheControl }) => {
  // Browser cache: 5 minutes
  cacheControl.set(
    "Cache-Control",
    new CacheControl().set("public", true).set("max-age", 300)
  );

  // General CDN: 1 hour
  cacheControl.set(
    "CDN-Cache-Control",
    new CacheControl().set("public", true).set("s-maxage", 3600)
  );

  // Vercel CDN: 24 hours
  cacheControl.set(
    "Vercel-CDN-Cache-Control",
    new CacheControl().set("public", true).set("s-maxage", 86400)
  );
});

💡 Supported Cache Directives

Directive	Type	Description
max-age	number	Maximum age in seconds for browser cache
s-maxage	number	Maximum age in seconds for shared caches (CDNs)
public	boolean	Response can be cached by any cache
private	boolean	Response should only be cached by browser
no-cache	boolean	Must revalidate with server before using cached version
no-store	boolean	Must not store any part of request/response
must-revalidate	boolean	Must revalidate stale responses with server
proxy-revalidate	boolean	Like must-revalidate but only for shared caches
immutable	boolean	Response will not change during its lifetime
stale-while-revalidate	number	Seconds to serve stale content while revalidating
stale-if-error	number	Seconds to serve stale content if revalidation fails
no-transform	boolean	Prohibits transformations like compression
must-understand	boolean	Only cache if cache understands requirements

🔗 Example Project

Check out the deployed example to see the plugin in action with a Next.js app and Vercel deployment.

🤝 Contributing

Contributions are welcome! Please feel free to submit a Pull Request.