A RESP protocol implementation and multiplexed Redis client library.

hask-redis-mux provides a full RESP protocol parser, Redis client with TLS support, CRC16 hash slot computation, and a multiplexed Redis Cluster client with connection pooling and automatic topology discovery.

hask-redis-mux

A multiplexed Redis client library for Haskell with full RESP protocol support, Redis Cluster topology discovery, connection pooling, and TLS.

Features

• Standalone & Cluster — works with single-node Redis and Redis Cluster
• Multiplexed pipelining — concurrent commands share a single TCP connection
• Typed returns via FromResp — parse responses as ByteString, Integer, Text, Bool, or custom types
• TLS support — connect over TLS with crypton
• Bracket-style resource management — withStandaloneClient / withClusterClient for exception-safe cleanup
• Connection pooling — automatic pool management for cluster nodes

Installation

Add to your .cabal file:

build-depends: hask-redis-mux >= 0.1 && < 0.2

Quick Start

{-# LANGUAGE OverloadedStrings #-}
import Database.Redis

main :: IO ()
main = do
  -- Connect to localhost:6379, run commands, auto-close
  result <- runRedis defaultStandaloneConfig $ do
    set "greeting" "hello"
    (val :: ByteString) <- get "greeting"
    return val
  print result  -- "hello"

Typed Returns with FromResp

Commands return polymorphic types via the FromResp typeclass. Just add a type annotation and the response is parsed automatically:

runRedis defaultStandaloneConfig $ do
  set "counter" "42"

  (n :: Integer)      <- get "counter"   -- 42
  (bs :: ByteString)  <- get "counter"   -- "42"
  (mt :: Maybe Text)  <- get "missing"   -- Nothing
  (ok :: Bool)        <- set "k" "v"     -- True (from +OK)

Bracket Pattern (Recommended)

Use bracket-style functions for exception-safe resource management:

-- Standalone
withStandaloneClient config $ \client ->
  runStandaloneClient client $ do
    set "key" "value"
    get "key"

-- Cluster
withClusterClient clusterConfig connector $ \client ->
  runClusterCommandClient client $ do
    set "key" "value"
    get "key"

Custom Configuration

import Database.Redis

main :: IO ()
main = do
  let config = StandaloneConfig
        { standaloneNodeAddress     = NodeAddress "redis.example.com" 6379
        , standaloneConnector       = clusterPlaintextConnector
        , standaloneMultiplexerCount = 4  -- 4 multiplexed connections
        }
  withStandaloneClient config $ \client ->
    runStandaloneClient client $ do
      set "key" "value"

Documentation

• Haddock API docs
• GitHub repository

License

MIT — see LICENSE for details.