Connect

Self-Managed Only

nats_stream

Publishes to a NATS Stream subject.

Deprecation notice

The NATS Streaming Server is being deprecated. Critical bug fixes and security fixes will be applied until June of 2023. NATS-enabled applications requiring persistence should use JetStream.

Authentication

There are several components within Redpanda Connect which uses NATS services. You will find that each of these components support optional advanced authentication parameters for NKeys and User Credentials.

See an in-depth tutorial.

NKey file

The NATS server can use these NKeys in several ways for authentication. The simplest is for the server to be configured with a list of known public keys. The server then generates a challenge for each connection request from a client, and the client must respond to the challenge by signing it with its private NKey configured in the nkey_file or nkey field.

More details.

User credentials

NATS server supports decentralized authentication based on JSON Web Tokens (JWT). Clients need an user JWT and a corresponding NKey secret when connecting to a server which is configured to use this authentication scheme.

The user_credentials_file field should point to a file containing both the private key and the JWT and can be generated with the nsc tool.

Alternatively, the user_jwt field can contain a plain text JWT and the user_nkey_seed field can contain the plain text NKey Seed.

More details.

Token

The token field can contain a plain text token string for token-based authentication.

User and password

The user and password fields can be used for username/password authentication.

Performance

This output benefits from sending multiple messages in flight in parallel for improved performance. You can tune the max number of in flight messages (or message batches) with the field max_in_flight.

Common
Advanced

output:
  label: ""
  nats_stream:
    urls: [] # No default (required)
    cluster_id: "" # No default (required)
    subject: "" # No default (required)
    client_id: ""
    max_in_flight: 64

output:
  label: ""
  nats_stream:
    urls: [] # No default (required)
    max_reconnects: 0 # No default (optional)
    cluster_id: "" # No default (required)
    subject: "" # No default (required)
    client_id: ""
    max_in_flight: 64
    tls:
      enabled: false
      skip_cert_verify: false
      enable_renegotiation: false
      root_cas: ""
      root_cas_file: ""
      client_certs: []
    tls_handshake_first: false
    auth:
      nkey_file: "" # No default (optional)
      nkey: "" # No default (optional)
      user_credentials_file: "" # No default (optional)
      user_jwt: "" # No default (optional)
      user_nkey_seed: "" # No default (optional)
      user: "" # No default (optional)
      password: "" # No default (optional)
      token: "" # No default (optional)
    inject_tracing_map: "" # No default (optional)

Fields

`auth`

Optional configuration of NATS authentication parameters.

Type: object

`auth.nkey`

Your NKey seed (private key) for NATS authentication. NKeys provide cryptographic authentication without passwords.

This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see Secrets.

Requires version 4.38.0 or later.

Type: string

# Examples:
nkey: UDXU4RCSJNZOIQHZNWXHXORDPRTGNJAHAHFRGZNEEJCPQTT2M7NLCNF4

`auth.nkey_file`

An optional file containing a NKey seed.

Type: string

# Examples:
nkey_file: ./seed.nk

`auth.password`

An optional plain text password (given along with the corresponding user name).

This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see Secrets.

Requires version 4.84.0 or later.

Type: string

`auth.token`

An optional plain text token.

This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see Secrets.

Requires version 4.84.0 or later.

Type: string

`auth.user`

An optional plain text user name (given along with the corresponding user password).

Requires version 4.84.0 or later.

Type: string

`auth.user_credentials_file`

An optional file containing user credentials which consist of a user JWT and corresponding NKey seed.

Type: string

# Examples:
user_credentials_file: ./user.creds

`auth.user_jwt`

An optional plaintext user JWT to use along with the corresponding user NKey seed.

This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see Secrets.

Requires version 4.16.0 or later.

Type: string

`auth.user_nkey_seed`

An optional plaintext user NKey seed to use along with the corresponding user JWT.

This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see Secrets.

Requires version 4.16.0 or later.

Type: string

`client_id`

The client ID to connect with.

Type: string

Default: ""

`cluster_id`

The cluster ID to publish to.

Type: string

`inject_tracing_map`

EXPERIMENTAL: A Bloblang mapping used to inject an object containing tracing propagation information into outbound messages. The specification of the injected fields will match the format used by the service wide tracer.

Requires version 4.23.0 or later.

Type: string

# Examples:
inject_tracing_map: meta = @.merge(this)

# ---

inject_tracing_map: root.meta.span = this

`max_in_flight`

The maximum number of messages to have in flight at a given time. Increase this to improve throughput.

Type: int

Default: 64

`max_reconnects`

The maximum number of times to attempt to reconnect to the server. If negative, it will never stop trying to reconnect.

Requires version 4.56.0 or later.

Type: int

`subject`

The subject to publish to.

Type: string

`tls`

Configure Transport Layer Security (TLS) settings to secure network connections. This includes options for standard TLS as well as mutual TLS (mTLS) authentication where both client and server authenticate each other using certificates. Key configuration options include enabled to enable TLS, client_certs for mTLS authentication, root_cas/root_cas_file for custom certificate authorities, and skip_cert_verify for development environments.

Type: object

`tls.client_certs[]`

A list of client certificates for mutual TLS (mTLS) authentication. Configure this field to enable mTLS, authenticating the client to the server with these certificates.

You must set tls.enabled: true for the client certificates to take effect.

Certificate pairing rules: For each certificate item, provide either:

Inline PEM data using both cert and key or
File paths using both cert_file and key_file.

Mixing inline and file-based values within the same item is not supported.

Type: array<object>

Default: []

# Examples:
client_certs:
  - cert: foo
    key: bar


# ---

client_certs:
  - cert_file: ./example.pem
    key_file: ./example.key

`tls.client_certs[].cert`

The plaintext certificate to use for TLS authentication. Must be paired with the corresponding private key in the key field when using inline PEM data for mTLS client certificates.

Type: string

Default: ""

`tls.client_certs[].cert_file`

The path to a file containing the certificate to use for TLS authentication. Must be paired with the corresponding private key file in the key_file field when using file-based configuration for mTLS client certificates.

Type: string

Default: ""

`tls.client_certs[].key`

Private key for mTLS client certificate as inline PEM data. Must correspond to the client certificate specified in the cert field. Use this field together with cert when providing certificate data inline rather than through files.

This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see Secrets.

Type: string

Default: ""

`tls.client_certs[].key_file`

Path to private key file for mTLS client certificate in PEM format. Must correspond to the client certificate specified in the cert_file field. Use this field together with cert_file when loading certificate data from files.

Type: string

Default: ""

`tls.client_certs[].password`

The password to use for the private key (specified in the key or key_file fields), if it is password-protected. The PKCS#1 and PKCS#8 formats are supported. Supports environment variable interpolation for secure password management.

The pbeWithMD5AndDES-CBC algorithm is obsolete and not supported for the PKCS#8 format. This algorithm does not authenticate the ciphertext, making it vulnerable to padding oracle attacks that can let an attacker recover the plaintext.

This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see Secrets.

Requires version 4.3.0 or later.

Type: string

Default: ""

# Examples:
password: foo

# ---

password: ${KEY_PASSWORD}

`tls.enable_renegotiation`

Whether to allow the remote server to repeatedly request renegotiation. Enable this option if you’re seeing the error message local error: tls: no renegotiation.

Requires version 3.45.0 or later.

Type: bool

Default: false

`tls.enabled`

Whether to enable TLS for secure connections. Set to true to enable TLS encryption. Required to be true for other TLS options (like client_certs, root_cas, etc.) to take effect.

Type: bool

Default: false

`tls.root_cas`

Specify a root certificate authority to use (optional). This is a string that represents a certificate chain from the parent-trusted root certificate, through possible intermediate signing certificates, to the host certificate. Use either this field for inline certificate data or root_cas_file for file-based certificate loading.

This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see Secrets.

Type: string

Default: ""

# Examples:
root_cas: |-
  -----BEGIN CERTIFICATE-----
  ...
  -----END CERTIFICATE-----

`tls.root_cas_file`

Specify the path to a root certificate authority file (optional). This is a file, often with a .pem extension, which contains a certificate chain from the parent-trusted root certificate, through possible intermediate signing certificates, to the host certificate. Use either this field for file-based certificate loading or root_cas for inline certificate data.

Type: string

Default: ""

# Examples:
root_cas_file: ./root_cas.pem

`tls.skip_cert_verify`

Whether to skip server-side certificate verification. Set to true only for testing environments as this reduces security by disabling certificate validation. When using self-signed certificates or in development, this may be necessary, but should never be used in production. Consider using root_cas or root_cas_file to specify trusted certificates instead of disabling verification entirely.

Type: bool

Default: false

`tls_handshake_first`

Whether to perform the initial TLS handshake before sending the NATS INFO protocol message. This is required when connecting to some NATS servers that expect TLS to be established immediately after connection, before any protocol negotiation.

Requires version 4.60.0 or later.

Type: bool

Default: false

`urls[]`

A list of URLs to connect to. If a list item contains commas, it will be expanded into multiple URLs.

Type: array<string>

# Examples:
urls:
  - "nats://127.0.0.1:4222"

# ---

urls:
  - "nats://username:password@127.0.0.1:4222"

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nats_stream

Authentication

NKey file

User credentials

Token

User and password

Performance

Fields

auth

auth.nkey

auth.nkey_file

auth.password

auth.token

auth.user

auth.user_credentials_file

auth.user_jwt

auth.user_nkey_seed

client_id

cluster_id

inject_tracing_map

max_in_flight

max_reconnects

subject

tls

tls.client_certs[]

tls.client_certs[].cert

tls.client_certs[].cert_file

tls.client_certs[].key

tls.client_certs[].key_file

tls.client_certs[].password

tls.enable_renegotiation

tls.enabled

tls.root_cas

tls.root_cas_file

tls.skip_cert_verify

tls_handshake_first

urls[]

`auth`

`auth.nkey`

`auth.nkey_file`

`auth.password`

`auth.token`

`auth.user`

`auth.user_credentials_file`

`auth.user_jwt`

`auth.user_nkey_seed`

`client_id`

`cluster_id`

`inject_tracing_map`

`max_in_flight`

`max_reconnects`

`subject`

`tls`

`tls.client_certs[]`

`tls.client_certs[].cert`

`tls.client_certs[].cert_file`

`tls.client_certs[].key`

`tls.client_certs[].key_file`

`tls.client_certs[].password`

`tls.enable_renegotiation`

`tls.enabled`

`tls.root_cas`

`tls.root_cas_file`

`tls.skip_cert_verify`

`tls_handshake_first`

`urls[]`