# Hanzo PubSub — Hanzo AI

> Managed NATS with JetStream for durable messaging. At-least-once delivery, key-value stores, object stores, and request-reply patterns.

NATS JetStream

# Hanzo PubSub

The bus everything else rides

PubSub moves messages between services on port 4222. Publish to a subject and everyone listening on it — or on a pattern that matches it — has the message. Add a stream and those same messages are written down too, so a consumer that was offline can start from the beginning, from a sequence number, or from a timestamp. Streams, key-value buckets, an object store and request-reply are one server, not four.

4222

Client port

Replay

From any point

Durable

Written to disk

Replicas

Set per stream

[Get Started](https://docs.hanzo.ai/docs/pubsub)[GitHub](https://github.com/hanzoai/pubsub)

## More than pub/sub

Durable streams, key-value, an object store and request-reply — one server, one connection, one set of credentials.

### Streams write it down

A stream captures the subjects you name and keeps them by age, by count or by bytes. A consumer starts at the beginning, at the newest message, at a sequence number or at a wall-clock time, and reads at the original pace or as fast as it can take them.

### Acked, so nothing goes quiet

A message is redelivered until a consumer acknowledges it. Publishers that stamp a message id get duplicates collapsed inside a window — two minutes unless you say otherwise. Ack every message, ack a sequence to cover everything below it, or ask for no acks at all when fire-and-forget is what you meant.

### Key-value buckets

A bucket is a stream that keeps the last value per key, so you get watches, per-key history and expiry from the same server and the same connection. It is where Hanzo Stream keeps its consumer offsets.

### Request-Reply

Send to a subject and wait for one answer. Put several instances of a service in a queue group on that subject and each request goes to exactly one of them — load balancing with nothing in front of them doing it.

### Object Store

Payloads too big to be a message are chunked into a stream and put back together on the way out, with a watch for when one changes. Same connection, same credentials, no second system to stand up.

### Accounts, not passwords

An account walls one tenant's subjects off from another's. Credentials are nkeys or signed JWTs rather than a shared secret, permissions are granted per subject, and TLS covers the wire.

## Publish and Subscribe

events.go

```
nc, _ := nats.Connect("nats://pubsub.hanzo.ai:4222") js, _ := nc.JetStream() // Create a durable stream js.AddStream(&nats.StreamConfig{ Name: "EVENTS", Subjects: []string{"events.>"}, Storage: nats.FileStorage, Replicas: 3, }) // Publish js.Publish("events.user.signup", []byte(`{"id":"usr_123"}`)) // Durable consumer with ack sub, _ := js.PullSubscribe("events.>", "my-service") msgs, _ := sub.Fetch(10) for _, msg := range msgs { process(msg.Data) msg.Ack() }
```

Open Source Revenue Sharing

### Up to 5% of compute goes back to open source

Every deployment is SBOM-verified. Contributors to NATS JetStream earn a share of compute revenue — transparent, on-chain, and customizable by the community.

[Connect & Earn](https://hanzo.ai/open-source/dividends)[Learn More](https://hanzo.ai/open-source)

Open Source Compute Dividends

### Up to 5% of compute goes back to OSS authors

Every Hanzo deployment tracks software dependencies via SBOM. When your code powers compute on Hanzo, the authors get paid — automatically.

USDHanzo NetworkETHSOLUSDCmore

[Connect GitHub](https://console.hanzo.ai?ref=oss-dividends)[How payouts work](https://hanzo.ai/open-source/dividends)

## Put it between your services

Free tier includes 1M messages/month.

[Get Started](https://docs.hanzo.ai/docs/pubsub)[View on GitHub](https://github.com/hanzoai/pubsub)

## Open source

License: Apache-2.0[hanzoai/pubsub](https://github.com/hanzoai/pubsub)

## Get Pubsub

Pub/sub messaging

[Deploy to Cloud](https://console.hanzo.ai/deploy)[Self-host](https://docs.hanzo.ai/docs/pubsub)