builderx-api-redis

name	builderx_api-redis
description	Patterns for using Redis caching, PubSub, and Poolboy in BuilderX API
metadata	{"author":"Vũ Lưu","version":"2026.03.25","source":"Source code builderx_api"}

BuilderX API Redis Skill

The builderx_api project uses the redix library combined with Erlang's :poolboy for connection pooling. Standard usages revolve entirely around the Redis.PubSub module (lib/redis/redis_pubsub.ex).

1. General Redis Commands

The Redis.PubSub module exposes wrapper functions for common Redis operations. Under the hood, they use Redix.command/2 within a :poolboy.transaction/2 call targeting the :redis_poolex pool.

Keys and Strings

# GET a key
{:ok, value} = Redis.PubSub.get("my_key")

# SET a key
{:ok, "OK"} = Redis.PubSub.set("my_key", "value")

# SET a key with expiration (in seconds)
{:ok, "OK"} = Redis.PubSub.set("my_key", "value", 3600)

# Delete keys
{:ok, deleted_count} = Redis.PubSub.del("my_key")
{:ok, deleted_count} = Redis.PubSub.del(["key1", "key2"])

# Expire an existing key
{:ok, 1} = Redis.PubSub.expire("my_key", 60)

Counters

# Increment by 1
{:ok, new_val} = Redis.PubSub.incr("visits")

# Increment by N
{:ok, new_val} = Redis.PubSub.incr("visits", 5)

Hash Maps

# Increment a field inside a hash
{:ok, new_val} = Redis.PubSub.hincrby("user:123", "login_count", 1)

# Get a field from a hash
{:ok, value} = Redis.PubSub.hget("user:123", "name")

# Get entire hash
{:ok, list_of_pairs} = Redis.PubSub.hgetall("user:123")

Sets

# Add to Set
{:ok, added_count} = Redis.PubSub.sadd("my_set", "item1")
{:ok, added_count} = Redis.PubSub.sadd("my_set", ["item2", "item3"])

# Remove from Set
{:ok, removed_count} = Redis.PubSub.srem("my_set", "item1")
{:ok, removed_count} = Redis.PubSub.srem("my_set", ["item2", "item3"])

# Get all members
{:ok, members} = Redis.PubSub.smembers("my_set")

2. Transactions

You can execute Redis commands transactionally via MULTI and EXEC using the wrappers:

Redis.PubSub.transaction() # Sends MULTI
Redis.PubSub.set("key1", "val1")
Redis.PubSub.set("key2", "val2")
Redis.PubSub.commit() # Sends EXEC

Note: Since these execute under standard HTTP pools without locking the connection strictly contextually in the Redix API wrappers mapped here, be cautious when using Redis transactions via standard global pool dispatch; ensure your pipeline design handles concurrency correctly.

3. PubSub Features

Through :redis_pubsub pool, builderx_api can support pub-sub channels.

# To subscribe the current process to a channel
Redis.PubSub.subscribe("chat_room_1", self())

# To unsubscribe
Redis.PubSub.unsubscribe("chat_room_1", self())

# To publish to a channel
{:ok, subscribers_received} = Redis.PubSub.publish("chat_room_1", "Hello World!")