Pub/Sub

Look up the publish and inspection commands on Redis and the subscribe methods on RedisPubSub.

Publishing and inspecting channels are ordinary commands on the Redis service. Subscribing holds a connection open, so it lives on RedisPubSub.

Example (Publishing and Subscribing)

import { ,  } from "effect";

import { ,  } from "@effect-kit/redis";

const  = .(
  .(function* () {
    const  = yield* ;
    const  = yield* ;

    const  = yield* .(["orders"]);

    const receivers = yield* .("orders", "order-1");            
const receivers: bigint

    const first = yield* ..(.(1), .);          
const first: PubSubMessage[]

    return { ,  };
  }),
);

subscribe needs a Scope and closes the subscription when the scope ends. For delivery gaps, limits and reconnects, see Pub/Sub.

Methods on `Redis`

Method	Command	Reply type	Purpose
`redis.publish`	`PUBLISH`	`bigint`	Publish a message to a channel and return the receiver count.
`redis.spublish`	`SPUBLISH`	`bigint`	Publish a message to a shard channel.
`redis.pubsubChannels`	`PUBSUB CHANNELS`	`readonly Uint8Array[]`	List active channels, optionally by pattern.
`redis.pubsubNumSub`	`PUBSUB NUMSUB`	`readonly (readonly [Uint8Array, bigint])[]`	Count subscribers per channel.
`redis.pubsubNumPat`	`PUBSUB NUMPAT`	`bigint`	Count pattern subscriptions.
`redis.pubsubShardChannels`	`PUBSUB SHARDCHANNELS`	`readonly Uint8Array[]`	List active shard channels.
`redis.pubsubShardNumSub`	`PUBSUB SHARDNUMSUB`	`readonly (readonly [Uint8Array, bigint])[]`	Count subscribers per shard channel.
`redis.pubsubHelp`	`PUBSUB HELP`	`readonly string[]`	Return the PUBSUB help text.

Methods on `RedisPubSub`

Method	Command	Reply type	Purpose
`pubsub.subscribe`	`SUBSCRIBE`	`{ events; messages; close }`	Subscribe to channels. `mode: "pattern"` or `"shard"` sends `PSUBSCRIBE` or `SSUBSCRIBE`.
`pubsub.psubscribe`	`PSUBSCRIBE`	`{ events; messages; close }`	Subscribe to patterns.
`pubsub.ssubscribe`	`SSUBSCRIBE`	`{ events; messages; close }`	Subscribe to shard channels.
`pubsub.unknownPushes`	none	`Stream<{ generation; value: RespValue }>`	Pushes the client did not recognize.
`pubsub.snapshot`	none	`Effect<{ generation; listeners; retiring; interests; retainedBytes }>`	Counters for the current connection.

subscribe, psubscribe and ssubscribe return an Effect that needs a Scope. events carries Ready and DeliveryGap events as well as messages. messages carries only messages and fails with a SubscriptionError on a gap.

`SubscribeOptions`

Prop

Type

PubSubMessage has _tag of "Message", "PatternMessage" or "ShardMessage", plus channel: Uint8Array, payload: Uint8Array, attributes and generation. PatternMessage also has pattern. SubscriptionEvent adds { _tag: "Ready" } and { _tag: "DeliveryGap" }.

Subscription limits are set under subscriptions. Upstash has no RedisPubSub. Use UpstashEvents.subscribe from @effect-kit/redis/upstash, which takes one channel and yields text.

Methods on RedisCopy Anchor Link

Methods on RedisPubSubCopy Anchor Link

SubscribeOptionsCopy Anchor Link

On this page

Methods on `Redis`

Methods on `RedisPubSub`

`SubscribeOptions`