Redis Client

Factory that wraps ioredis with lifecycle management. All Redis extensions accept this client.

// src/lib/server/redis.js
import { createRedisClient } from 'svelte-adapter-uws-extensions/redis';

export const redis = createRedisClient({
  url: 'redis://localhost:6379',
  keyPrefix: 'myapp:'   // optional, prefixes all keys
});

Options

API

Pub/Sub Bus

Distributes platform.publish() calls across multiple server instances via Redis pub/sub. Each instance publishes locally AND to Redis. Incoming Redis messages are forwarded to the local platform with echo suppression - messages from the same instance are ignored.

When to use over the built-in plugin: The core adapter’s platform.publish() only reaches clients connected to the current process. If you run two or more instances behind a load balancer, clients on instance A will not see messages published on instance B. The pub/sub bus fixes that.

Setup

// src/lib/server/bus.js
import { redis } from './redis.js';
import { createPubSubBus } from 'svelte-adapter-uws-extensions/redis/pubsub';

export const bus = createPubSubBus(redis);

Usage

// src/hooks.ws.js
import { bus } from '$lib/server/bus';

let distributed;

export function open(ws, { platform }) {
  // Start subscriber (idempotent, only subscribes once)
  bus.activate(platform);
  // Get a wrapped platform that publishes to Redis + local
  distributed = bus.wrap(platform);
}

export function message(ws, { data, platform }) {
  const msg = JSON.parse(Buffer.from(data).toString());
  // This publish reaches local clients AND all other instances
  distributed.publish('chat', 'message', msg);
}

Options

API