Tag-Based Cache

@farbenmeer/tag-based-cache is a cache library that supports tag-based invalidation. Instead of invalidating individual keys, you can invalidate entire groups of cache entries by their tags.

The package provides three implementations of the same Cache interface:

• InMemoryCache — SQLite in-memory database, suitable for single-process use.
• FilesystemCache — SQLite file-based database, persists data to disk.
• RedisCache — Redis-backed distributed cache with pub/sub support for multi-host setups.

All implementations are interchangeable since they conform to the same Cache interface.

Installation

npm install @farbenmeer/tag-based-cache

Quick Start

import { InMemoryCache } from "@farbenmeer/tag-based-cache/in-memory-cache";

const cache = new InMemoryCache();

// Store an entry with tags
await cache.set({
  key: "user:1",
  data: { name: "Alice" },
  ttl: 3600,
  tags: ["users", "user:1"],
});

// Retrieve it
const entry = await cache.get("user:1");
// { data: { name: "Alice" }, attachment: null }

// Invalidate all entries tagged "users"
await cache.delete(["users"]);

await cache.get("user:1"); // null

Usage with TApi

Pass a cache instance to createRequestHandler to enable server-side caching:

import { createRequestHandler } from "@farbenmeer/tapi/server";
import { InMemoryCache } from "@farbenmeer/tag-based-cache/in-memory-cache";

const cache = new InMemoryCache();
const handleRequest = createRequestHandler(api, { cache });

See Caching Strategies for the full picture of how caching works across all layers in TApi.