SUBSCRIBE

SUBSCRIBE makes the connection receive every message later published with PUBLISH to any of the given channels. Messages are not stored: a subscriber only gets messages published while it is subscribed. In a cluster, a message published on any node reaches subscribers on every node.

The server sends one confirmation per channel. After that a RESP2 connection is in subscribed mode: it receives messages as they arrive and accepts only SUBSCRIBE, PSUBSCRIBE, SSUBSCRIBE, their UNSUBSCRIBE counterparts, PUBLISH, SPUBLISH, PUBSUB, PING, QUIT and RESET. Other commands reply with ERR Can't execute '<command>': only (P|S)SUBSCRIBE / (P|S)UNSUBSCRIBE / PING / QUIT / RESET are allowed in this context. A RESP3 connection (after HELLO 3) can run any command while it is subscribed. The connection leaves subscribed mode when it has no channel, pattern or shard channel subscriptions left.

Return value

For each channel, a confirmation:

Element	Value
1	Bulk string subscribe
2	Bulk string: the channel
3	Integer: the number of channels and patterns this connection is now subscribed to

Each message then arrives as message, the channel, and the payload. On RESP2 these are arrays; on RESP3 they are push messages with the same elements.

Examples

127.0.0.1:6379> SUBSCRIBE news alerts
1) "subscribe"
2) "news"
3) (integer) 1
1) "subscribe"
2) "alerts"
3) (integer) 2
1) "message"
2) "news"
3) "release 2.0 is out"

Compatibility

Same replies and message format as Redis 7 and Valkey 8. One difference in subscribed mode: a RESP2 connection may also run PUBLISH, SPUBLISH and PUBSUB, which Redis refuses there.

See also

UNSUBSCRIBE, PUBLISH, PSUBSCRIBE, SSUBSCRIBE, PUBSUB