NatsEx

An idiomatic Elixir client for Nats.io messaging system

Currently PubSub functionality is implemented.

Getting started

You can start a connection with Natsd like this. See NatsEx.Connection for configuration options.

{:ok, conn} = NatsEx.Connection.connection

Subscription

For subscription to a certain topic, you can use sub/2 or sub/3 in NatsEx.Connection module. You can also give a queue group for the subscription.

:ok = NatsEx.Connection.sub(conn, "foo.bar") # No queue group
:ok = NatsEx.Connection.sub(conn, "foo.bar", 22) # Queue group 22

When a new message comes to a certain topic, a new message is received by all the subscribers. The message format is {:nats_ex, :msg, subject, reply_to_subject, payload}

When the connection is down(closed by the server), all the subscribers receive a message {:nats_ex, :conn_down}

Publishing

For publishing to a certain topic, you can use pub/3 or pub/4 in NatsEx.Connection module. reply_to topic is optional.

:ok = NatsEx.Connection.pub(conn, "foo.bar", "This is a payload", "REPLY_SUBJECT")

Unsubscription

You can unsubscribe to a certain topic by using unsub/2 or unsub/3 in NatsEx.Connection module. You can also specify the number of messages, after which the subscriber will be automatically subscribed.

:ok = NatsEx.Connection.unsub(conn, "foo.bar", 10) # 10 is number of messages until unsubscription. This is optional

Installation

nats_ex is available on Hex. For installing, you can do this:

1. Add nats_ex to your list of dependencies in mix.exs:

```elixir
def deps do
  [{:nats_ex, "~> 0.1"}]
end
```

2. Ensure nats_ex is started before your application:

```elixir
def application do
  [applications: [:nats_ex]]
end
```

TODO

• Authorization
• TLS
• Publish, Subscribe
• Request, Reply
• Nats Streaming

License

MIT License. Please see LICENSE.md for more details.