hono-universal-cache

Universal cache middleware for Hono powered by unstorage.

Cache API responses across any runtime - Cloudflare Workers, Vercel Edge, Node.js, Bun, Deno, and more.

Note: Optimized for API responses (JSON, text, HTML). For static assets (images, videos, files), use CDN/edge caching instead.

Features

✨ Universal Runtime Support - Works everywhere Hono works
🗄️ Multiple Storage Drivers - Memory, Redis, Cloudflare KV, Vercel KV, filesystem, and more
⚡ TTL Support - Automatic expiration with configurable time-to-live
🎯 Selective Caching - Control what gets cached by status code
🔑 Custom Key Generation - Flexible cache key strategies
🪶 Lightweight - Minimal overhead, focused on storage operations
🎨 Simple & Predictable - No magic, just storage-based caching
📦 Efficient Storage - Optimized for text-based API responses

Installation

npm install hono-universal-cache
# or
pnpm add hono-universal-cache
# or
yarn add hono-universal-cache

Note: unstorage is included as a dependency - no need to install it separately!

Quick Start

Basic Usage (In-Memory)

import { Hono } from "hono";
import { universalCache } from "hono-universal-cache";

const app = new Hono();

app.use(
  "*",
  universalCache({
    cacheName: "my-app-cache",
    ttl: 3600, // 1 hour
  }),
);

app.get("/api/data", (c) => {
  return c.json({ timestamp: Date.now() });
});

export default app;

With Custom Storage Driver

import { createStorage } from "unstorage";
import redisDriver from "unstorage/drivers/redis";

const storage = createStorage({
  driver: redisDriver({
    host: "localhost",
    port: 6379,
  }),
});

app.use(
  "*",
  universalCache({
    cacheName: "api-cache",
    storage,
    ttl: 3600,
  }),
);

Runtime-Specific Examples

Cloudflare Workers

import { Hono } from "hono";
import { universalCache } from "hono-universal-cache";
import { createStorage } from "unstorage";
import cloudflareKVBindingDriver from "unstorage/drivers/cloudflare-kv-binding";

type Env = {
  MY_KV: KVNamespace;
};

const app = new Hono<{ Bindings: Env }>();

app.use("*", async (c, next) => {
  const storage = createStorage({
    driver: cloudflareKVBindingDriver({
      binding: c.env.MY_KV,
    }),
  });

  return universalCache({
    cacheName: "worker-cache",
    storage,
    ttl: 3600,
  })(c, next);
});

export default app;

Vercel Edge

import { createStorage } from "unstorage";
import vercelKVDriver from "unstorage/drivers/vercel-kv";

const storage = createStorage({
  driver: vercelKVDriver({
    // Auto-detects from environment:
    // KV_REST_API_URL and KV_REST_API_TOKEN
  }),
});

app.use(
  "*",
  universalCache({
    cacheName: "edge-cache",
    storage,
    ttl: 3600,
  }),
);

Node.js / Bun (Filesystem)

import { createStorage } from "unstorage";
import fsDriver from "unstorage/drivers/fs";

const storage = createStorage({
  driver: fsDriver({
    base: "./cache",
  }),
});

app.use(
  "*",
  universalCache({
    cacheName: "fs-cache",
    storage,
    ttl: 3600,
  }),
);

Redis

import { createStorage } from "unstorage";
import redisDriver from "unstorage/drivers/redis";

const storage = createStorage({
  driver: redisDriver({
    host: "localhost",
    port: 6379,
    // password: 'your-password'
  }),
});

app.use(
  "*",
  universalCache({
    cacheName: "redis-cache",
    storage,
    ttl: 3600,
  }),
);

API Reference

universalCache(options)

Creates a Hono middleware for response caching.

Options

type CacheOptions = {
  // Required: Cache namespace
  cacheName: string | ((c: Context) => Promise<string> | string);

  // Optional: Unstorage instance (defaults to in-memory)
  storage?: Storage;

  // Optional: Time-to-live in seconds
  ttl?: number;

  // Optional: Status codes to cache (default: [200])
  cacheableStatusCodes?: number[];

  // Optional: Custom cache key generator
  keyGenerator?: (c: Context) => Promise<string> | string;
};

Common Use Cases

Dynamic Cache Names

Cache different tenants or users separately:

app.use(
  "*",
  universalCache({
    cacheName: (c) => {
      const tenant = c.req.header("X-Tenant-ID") || "default";
      return `cache:${tenant}`;
    },
    storage,
    ttl: 3600,
  }),
);

Custom Key Generation

Cache based on custom logic (e.g., ignore specific query params):

app.use(
  "*",
  universalCache({
    cacheName: "api-cache",
    keyGenerator: (c) => {
      const url = new URL(c.req.url);
      // Ignore tracking parameters
      url.searchParams.delete("utm_source");
      url.searchParams.delete("utm_campaign");
      return url.toString();
    },
    storage,
  }),
);

Selective Caching by Status Code

Cache successful and redirect responses:

app.use(
  "*",
  universalCache({
    cacheName: "selective-cache",
    cacheableStatusCodes: [200, 201, 301, 302],
    storage,
  }),
);

Storage Drivers

Use any unstorage driver:

Popular Drivers

• Memory - unstorage/drivers/memory (default, ephemeral)
• Filesystem - unstorage/drivers/fs (Node.js/Bun)
• Redis - unstorage/drivers/redis (persistent, distributed)
• Cloudflare KV - unstorage/drivers/cloudflare-kv-binding
• Vercel KV - unstorage/drivers/vercel-kv
• MongoDB - unstorage/drivers/mongodb
• Upstash Redis - unstorage/drivers/upstash
• LRU Cache - unstorage/drivers/lru-cache (in-memory with eviction)

Cloud Storage

• AWS S3 - unstorage/drivers/s3
• Azure Blob - unstorage/drivers/azure-storage-blob
• Cloudflare R2 - unstorage/drivers/cloudflare-r2-binding
• Vercel Blob - unstorage/drivers/vercel-blob

See all drivers in the unstorage documentation.

How It Works

1. Request arrives → Middleware generates cache key
2. Check cache → Retrieve from storage if exists and not expired
3. Cache hit → Return cached response immediately
4. Cache miss → Execute route handler
5. Check cacheability → Verify status code is cacheable
6. Store response → Save text body to storage with TTL metadata (non-blocking)
7. Return response → Send to client

Important Notes

Optimized for API Responses

This middleware is designed for text-based API responses:

• ✅ JSON APIs - Perfect use case
• ✅ Text responses - Works great
• ✅ HTML pages - Fully supported
• ✅ XML/RSS feeds - No problem
• ❌ Binary assets (images, PDFs, videos) - Use CDN/edge caching instead

Why not binary? The middleware uses response.text() for optimal storage efficiency. For static assets, use:

• CDN caching (Cloudflare, CloudFront)
• Object storage (S3, R2, Blob Storage)
• Hono's built-in static file serving with CDN

Storage-Only Caching

This middleware handles server-side storage caching only:

• ✅ Stores responses in Redis, KV, filesystem, etc.
• ✅ Caches based on status codes and TTL configuration
• 💡 Independent of HTTP caching headers - works purely at the storage layer

Non-blocking Cache Writes

Cache writes happen asynchronously and don't block responses:

• Cloudflare Workers/Vercel Edge: Uses waitUntil() for background writes
• Other runtimes: Uses promises with error handling

Advanced Usage

CacheManager API

Access the low-level cache manager for manual operations:

import { CacheManager } from "hono-universal-cache";
import { createStorage } from "unstorage";

const storage = createStorage();
const cache = new CacheManager(storage, 3600); // 1 hour TTL

// Manual cache operations
await cache.set("key", response);
const cached = await cache.get("key");
const exists = await cache.has("key");
await cache.delete("key");
await cache.clear();
const keys = await cache.keys();

Per-Route Caching

Apply caching to specific routes only:

const app = new Hono();

// Global middleware without cache
app.use("*", logger());

// Cache only API routes
app.use(
  "/api/*",
  universalCache({
    cacheName: "api-cache",
    storage,
    ttl: 300, // 5 minutes
  }),
);

// Cache product pages longer
app.use(
  "/products/*",
  universalCache({
    cacheName: "products-cache",
    storage,
    ttl: 3600, // 1 hour
  }),
);

License

MIT

Contributing

Contributions welcome! Please open an issue or PR.

Credits

• Hono - Ultrafast web framework
• unstorage - Universal storage layer