NATS

Pub/Sub Commands

Publish and subscribe to NATS subjects for real-time messaging. Learn core pub/sub patterns, wildcards, request/reply, and queue groups for load balancing.

7 commands

Pro Tips

Use 'nats sub "events.>"' to subscribe to all events using the '>' wildcard for multi-level matching.

Use 'nats request service.ping "hello"' for request/reply patterns — waits for a single response.

Use '--queue mygroup' on subscribers for load balancing — only one subscriber per group gets each message.

Common Mistakes

Core NATS is fire-and-forget with no persistence. Use JetStream if you need guaranteed delivery.

Wildcards '*' matches one token, '>' matches one or more. 'events.*' won't match 'events.user.created'.

Commands

Publish message

$ nats pub subject 'Hello World'

Publish a message to a subject.

Publish multiple

$ nats pub demo "message {{.Count}}" --count=10

Publish multiple messages with templating.

Subscribe to subject

$ nats sub 'events.>'

Subscribe using wildcard pattern.

Queue group subscribe

$ nats sub orders --queue=workers

Join queue group for load-balanced delivery.

Request-reply

$ nats request greet.joe 'Hello'

Send request and wait for response.

Reply service

$ nats reply greet.> 'Hello!'

Listen for requests and send responses.

Benchmark pub/sub

$ nats bench test --pub 10 --sub 10 --msgs 10000 --size 512

Benchmark with 10 publishers and subscribers.