Documentation#

Welcome to the Layercache documentation.

Layercache stacks memory, Redis, and disk behind a single API with stampede prevention, tag invalidation, stale-while-revalidate, and full observability.

#How It Works

Every read follows the same path:

1. Check L1 Memory first (fastest, in-process).
2. If miss, check L2 Redis (shared across instances).
3. If miss, check L3 Disk (persistent fallback).
4. If all miss, run the origin fetcher once (single-flight).
5. Backfill upper layers so next reads return faster.

Layercache keeps responses stable under pressure with stale serving, circuit breakers, and timeout guards.

#Version 3.0 Highlights

Layercache 3.0 tightens production defaults and updates the docs/runtime surface for distributed deployments:

• RedisTagIndex now uses 16 known-key shards by default, with a migrate-tag-index CLI command for older single-set indexes.
• Production CLI commands reject plaintext redis:// URLs unless --allow-plaintext is passed.
• Express and Hono implicit URL cache keys strip sensitive query parameters, and non-2xx JSON responses are skipped by default.
• RedisInvalidationBus supports signed invalidation messages, and RedisGenerationStore persists generation rotations across instances.
• The documentation site now runs on Rspress and deploys through GitHub Pages.

Read the migration guide before upgrading an existing Redis-backed deployment.

#Quick Links

• Getting Started — Install and configure your first cache stack
• Tutorial — 10-step walkthrough of production features
• API Reference — Complete method and option documentation
• Integrations — Express, Fastify, NestJS, Hono, tRPC, GraphQL