Authenticating with a User and Password

For this example, start the server using:

nats-server --user myname --pass password

You can encrypt passwords to pass to nats-server using a simple tool:

nats server passwd

Output

? Enter password [? for help] **********************
? Reenter password [? for help] **********************
$2a$11$qbtrnb0mSG2eV55xoyPqHOZx/lLBlryHRhU3LK2oOPFRwGF/5rtGK

and use the hashed password in the server config. The client still uses the plain text version.

The code uses localhost:4222 so that you can start the server on your machine to try them out.

Connecting with a User/Password

When logging in with a password nats-server will take either a plain text password or an encrypted password.

{% tabs %} {% tab title=”Go” %}

// Set a user and plain text password
nc, err := nats.Connect("127.0.0.1", nats.UserInfo("myname", "password"))
if err != nil {
    log.Fatal(err)
}
defer nc.Close()
// Do something with the connection

{% endtab %}

{% tab title=”Java” %}

Options options = new Options.Builder().
                            server("nats://localhost:4222").
                            userInfo("myname","password"). // Set a user and plain text password
                            build();
Connection nc = Nats.connect(options);
// Do something with the connection
nc.close();

{% endtab %}

{% tab title=”JavaScript” %}

 const nc = await connect({
      port: ns.port,
      user: "byname",
      pass: "password",
});

{% endtab %}

{% tab title=”Python” %}

nc = NATS()
await nc.connect(servers=["nats://myname:password@demo.nats.io:4222"])
# Do something with the connection.

{% endtab %}

{% tab title=”Ruby” %}

require 'nats/client'
NATS.start(servers:["nats://myname:password@127.0.0.1:4222"], name: "my-connection") do |nc|
   nc.on_error do |e|
    puts "Error: #{e}"
  end
   nc.on_reconnect do
    puts "Got reconnected to #{nc.connected_server}"
  end
  nc.on_disconnect do |reason|
    puts "Got disconnected! #{reason}"
  end
  nc.close
end

{% endtab %}

{% tab title=”C” %}

natsConnection      *conn      = NULL;
natsOptions         *opts      = NULL;
natsStatus          s          = NATS_OK;
s = natsOptions_Create(&opts);
if (s == NATS_OK)
    s = natsOptions_SetUserInfo(opts, "myname", "password");
if (s == NATS_OK)
    s = natsConnection_Connect(&conn, opts);
(...)
// Destroy objects that were created
natsConnection_Destroy(conn);
natsOptions_Destroy(opts);

{% endtab %} {% endtabs %}

Connecting with a User/Password in the URL

Most clients make it easy to pass the user name and password by accepting them in the URL for the server. This standard format is:

nats://user:password@server:port

Using this format, you can connect to a server using authentication as easily as you connected with a URL:

{% tabs %} {% tab title=”Go” %}

// Set a user and plain text password
nc, err := nats.Connect("myname:password@127.0.0.1")
if err != nil {
    log.Fatal(err)
}
defer nc.Close()
// Do something with the connection

{% endtab %}

{% tab title=”Java” %}

Connection nc = Nats.connect("nats://myname:password@localhost:4222");
// Do something with the connection
nc.close();

{% endtab %}

{% tab title=”JavaScript” %}

// JavaScript clients don't support username/password in urls use `user` and `pass` options.

{% endtab %}

{% tab title=”Python” %}

nc = NATS()
await nc.connect(servers=["nats://myname:password@demo.nats.io:4222"])
# Do something with the connection.

{% endtab %}

{% tab title=”Ruby” %}

require 'nats/client'
NATS.start(servers:["nats://myname:password@127.0.0.1:4222"], name: "my-connection") do |nc|
   nc.on_error do |e|
    puts "Error: #{e}"
  end
   nc.on_reconnect do
    puts "Got reconnected to #{nc.connected_server}"
  end
  nc.on_disconnect do |reason|
    puts "Got disconnected! #{reason}"
  end
  nc.close
end

{% endtab %}

{% tab title=”C” %}

natsConnection      *conn      = NULL;
natsOptions         *opts      = NULL;
natsStatus          s          = NATS_OK;
s = natsOptions_Create(&opts);
if (s == NATS_OK)
    s = natsOptions_SetURL(opts, "nats://myname:password@127.0.0.1:4222");
if (s == NATS_OK)
    s = natsConnection_Connect(&conn, opts);
(...)
// Destroy objects that were created
natsConnection_Destroy(conn);
natsOptions_Destroy(opts);

{% endtab %} {% endtabs %}