# Redis
URL: https://wwadd.dev/tools/redis · Official site: https://redis.io
Kind: In-memory key-value store · License: Open source · Last verified: 2026-09-28

An in-memory data structure store used as a cache, session store, rate limiter, queue, and pub/sub broker. Responses are typically sub-millisecond because data lives in RAM.

Reach for it when:
- Caching and sessions
- Rate limiting
- Pub/sub and lightweight queues

Worth knowing: Licensing changed in 2024 and AGPLv3 was added in 2025; Valkey is the BSD-licensed community fork.

Repository: https://github.com/redis/redis
Recorded SPDX baseline: NOASSERTION