Plain Text Passwords

You can authenticate one or more clients using username and passwords; this enables you to have greater control over the management and issuance of credential secrets.

Single User

authorization: {
user: a,
password: b
You can also specify a single username/password by:
> nats-server --user a --pass b

Multiple users

authorization: {
users: [
{user: a, password: b},
{user: b, password: a}

Bcrypted Passwords

Username/password also supports bcrypted passwords using the nats tool. Simply replace the clear text password with the bcrypted entries:
> nats server passwd
? Enter password [? for help] **********************
? Reenter password [? for help] **********************
And on the configuration file:
authorization: {
users: [
{user: a, password: "$2a$11$V1qrpBt8/SLfEBr4NJq4T.2mg8chx8.MTblUiTBOLV3MKDeAy.f7u"},

Reloading a Configuration

As you add/remove passwords from the server configuration file, you'll want your changes to take effect. To reload without restarting the server and disconnecting clients, do:
> nats-server --signal reload