Redis

Redis is an in-memory data structure server. It speaks a simple text-based protocol (RESP) on TCP and exposes high-level data types — strings, lists, hashes, sets, sorted sets, streams, hyperloglogs, bitmaps, geospatial indexes, vector sets — along with Pub/Sub, transactions, Lua scripting, replication, sharding, and a pluggable module API.

This wiki covers the source layout under src/, the bundled dependencies under deps/, the Tcl-based test harness in tests/, and the toolchain that builds redis-server, redis-sentinel, redis-cli, redis-benchmark, redis-check-rdb, and redis-check-aof.

What is in the repository

Directory	Purpose
src/	The C source for the Redis server, CLI, and the RDB/AOF check tools.
src/commands/	One JSON file per Redis command describing its arguments, flags, ACL category, and reply schema.
src/modules/	Sample modules (helloworld.c, hellotype.c, helloblock.c, …) demonstrating the Module API.
deps/	Bundled, in-tree third-party libraries: jemalloc, Lua 5.1, hiredis, hdr_histogram, linenoise, fpconv, xxhash.
tests/	Tcl-based integration test harness: unit/, integration/, cluster/, sentinel/, support/.
modules/	External-style modules built into the server when BUILD_WITH_MODULES=yes is passed (vector-sets/ is included; the rest are stubs that download from upstream).
utils/	Helper scripts: cluster bootstrappers, certificate generation, command-table code generation, init scripts, systemd units.
redis.conf, sentinel.conf	The example configuration files shipped with each release.

How to read this wiki

• Start with Architecture for the high-level picture: event loop, client lifecycle, persistence, replication, cluster, modules.
• Use Getting started to build, run, and exercise Redis from source.
• Drill into a deployable in Applications: one page per binary.
• Drill into a subsystem in Systems: event loop, networking, persistence, replication, cluster, scripting, modules, ACL, memory management, IO threads, Pub/Sub, tracking.
• Drill into a data structure in Primitives: SDS, dict, listpack/quicklist, rax, intset, kvstore, robj, ebuckets, stream radix.
• Drill into a feature in Features: the user-visible data types, key expiration, transactions, keyspace notifications.
• Look up a term in the Glossary.

Project facts

• Source language: C99 / GNU11 (auto-detected; falls back to C99 if the compiler does not have <stdatomic.h>).
• License: tri-license RSALv2 / SSPLv1 / AGPLv3 (see LICENSE.txt). Earlier history is BSD-3 (see REDISCONTRIBUTIONS.txt).
• First commit: March 2009. Original author: Salvatore Sanfilippo ("antirez").
• Build system: GNU Make. The top-level Makefile delegates to src/Makefile, which in turn builds everything in deps/ first.
• Test harness: Tcl (tcl8.6+); driven from tests/test_helper.tcl via the runtest, runtest-cluster, runtest-sentinel, and runtest-moduleapi shell wrappers.
• Cross-platform: Linux, macOS, FreeBSD, NetBSD, OpenBSD, DragonFly, Haiku. Windows is not supported by upstream.

Quick links

• Architecture diagrams
• Build and run
• Glossary
• By the numbers
• Lore
• Contributing workflow
• Module API
• RESP protocol