NATS

The NATS input connects to a NATS server and supports two modes: regular subscriptions (regular) and JetStream pull consumers (jet_stream). As a channel-based input it follows the engine's cancellation-safety contract: dropping a pending read never loses an already-decoded message (see Input Delivery Semantics).

Configuration

Field	Type	Required	Default	Description
type	string	yes	—	Constant value "nats"
url	string	yes	—	NATS server URL, e.g. nats://host:4222; multiple servers separated by commas
mode	object	yes	—	Operating mode, see table below (tagged enum, distinguished by the type field)
auth	object	no	—	Authentication configuration, see table below

mode (regular)

Field	Type	Required	Description
type	string	yes	"regular"
subject	string	yes	NATS subject to subscribe to
queue_group	string	no	Queue group name

mode (jet_stream)

Field	Type	Required	Description
type	string	yes	"jet_stream"
stream	string	yes	Stream name
consumer_name	string	yes	Consumer name
durable_name	string	no	Durable consumer name

auth

Field	Type	Required	Description
username	string	no	Username
password	string	no	Password (used together with username)
token	string	no	Token; takes precedence over username/password when both are present

Examples

yaml

input:
  type: "nats"
  url: "nats://localhost:4222"
  mode:
    type: "regular"
    subject: "my.subject"
    queue_group: "my_group"

yaml

input:
  type: "nats"
  url: "nats://localhost:4222"
  mode:
    type: "jet_stream"
    stream: "my_stream"
    consumer_name: "my_consumer"
    durable_name: "my_durable"
  auth:
    token: "my_token"

TLS

Use a tls:// URL scheme to connect over TLS (for example tls://nats.example.com:4422); async-nats negotiates TLS natively for tls:// URLs and requires the server to support TLS.