# nats_jetstream

> For the complete documentation index, see [llms.txt](https://docs.redpanda.com/llms.txt). Component-specific: [cloud-data-platform-full.txt](https://docs.redpanda.com/cloud-data-platform-full.txt)

---
title: nats_jetstream
latest-operator-version: v26.1.4
latest-console-tag: v3.7.3
latest-connect-version: 4.93.0
latest-redpanda-tag: v26.1.9
docname: connect/components/outputs/nats_jetstream
page-component-name: cloud-data-platform
page-version: master
page-component-version: master
page-component-title: Cloud
page-relative-src-path: connect/components/outputs/nats_jetstream.adoc
page-edit-url: https://github.com/redpanda-data/cloud-docs/edit/main/modules/develop/pages/connect/components/outputs/nats_jetstream.adoc
page-git-created-date: "2024-09-09"
page-git-modified-date: "2026-05-26"
---

<!-- Source: https://docs.redpanda.com/cloud-data-platform/develop/connect/components/outputs/nats_jetstream.md -->

**Type:** Output ▼

[Output](https://docs.redpanda.com/cloud-data-platform/develop/connect/components/outputs/nats_jetstream/)[Input](https://docs.redpanda.com/cloud-data-platform/develop/connect/components/inputs/nats_jetstream/)

**Available in:** Cloud, [Self-Managed](https://docs.redpanda.com/connect/components/outputs/nats_jetstream/%20%22View%20the%20Self-Managed%20version%20of%20this%20component%22)

Write messages to a NATS JetStream subject.

#### Common

```yml
outputs:
  label: ""
  nats_jetstream:
    urls: [] # No default (required)
    subject: "" # No default (required)
    headers: {}
    metadata:
      include_prefixes: []
      include_patterns: []
    max_in_flight: 1024
```

#### Advanced

```yml
outputs:
  label: ""
  nats_jetstream:
    urls: [] # No default (required)
    max_reconnects: "" # No default (optional)
    subject: "" # No default (required)
    headers: {}
    metadata:
      include_prefixes: []
      include_patterns: []
    max_in_flight: 1024
    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)
```

## [](#connection-name)Connection name

When monitoring and managing a production [NATS system](https://docs.nats.io/nats-concepts/overview), it is often useful to know which connection a message was sent or received from. To achieve this, set the connection name option when creating a NATS connection. Redpanda Connect can then automatically set the connection name to the NATS component label, so that monitoring tools between NATS and Redpanda Connect can stay in sync.

## [](#authentication)Authentication

A number of Redpanda Connect components use NATS services. Each of these components support optional, advanced authentication parameters for [NKeys](https://docs.nats.io/nats-server/configuration/securing_nats/auth_intro/nkey_auth) and [user credentials](https://docs.nats.io/using-nats/developer/connecting/creds).

For an in-depth guide, see the [NATS documentation](https://docs.nats.io/running-a-nats-service/nats_admin/security/jwt).

### [](#nkeys)NKeys

NATS server can use NKeys in several ways for authentication. The simplest approach is to configure the server with a list of user’s public keys. The server can then generate 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.

For more details, see the [NATS documentation](https://docs.nats.io/running-a-nats-service/configuration/securing_nats/auth_intro/nkey_auth).

### [](#user-credentials)User credentials

NATS server also supports decentralized authentication based on JSON Web Tokens (JWTs). When a server is configured to use this authentication scheme, clients need a [user JWT](https://docs.nats.io/nats-server/configuration/securing_nats/jwt#json-web-tokens) and a corresponding [NKey secret](https://docs.nats.io/running-a-nats-service/configuration/securing_nats/auth_intro/nkey_auth) to connect.

You can use either of the following methods to supply the user JWT and NKey secret:

-   In the `user_credentials_file` field, enter the path to a file containing both the private key and the JWT. You can generate the file using the [nsc tool](https://docs.nats.io/nats-tools/nsc).

-   In the `user_jwt` field, enter a plain text JWT, and in the `user_nkey_seed` field, enter the plain text NKey seed or private key.


For more details about authentication using JWTs, see the [NATS documentation](https://docs.nats.io/using-nats/developer/connecting/creds).

## [](#fields)Fields

### [](#auth)`auth`

Optional configuration of NATS authentication parameters.

**Type**: `object`

### [](#auth-nkey)`auth.nkey`

Your NKey seed or private key for NATS authentication. NKeys provide secure, cryptographic authentication without passwords.

> ⚠️ **CAUTION**
>
> This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see [Manage Secrets](https://docs.redpanda.com/cloud-data-platform/develop/connect/configuration/secret-management/) before adding it to your configuration.

**Type**: `string`

```yaml
# Examples:
nkey: UDXU4RCSJNZOIQHZNWXHXORDPRTGNJAHAHFRGZNEEJCPQTT2M7NLCNF4
```

### [](#auth-nkey_file)`auth.nkey_file`

An optional file containing a NKey seed.

**Type**: `string`

```yaml
# Examples:
nkey_file: ./seed.nk
```

### [](#auth-password)`auth.password`

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

> ⚠️ **CAUTION**
>
> This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see [Manage Secrets](https://docs.redpanda.com/cloud-data-platform/develop/connect/configuration/secret-management/) before adding it to your configuration.

**Type**: `string`

### [](#auth-token)`auth.token`

An optional plain text token.

> ⚠️ **CAUTION**
>
> This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see [Manage Secrets](https://docs.redpanda.com/cloud-data-platform/develop/connect/configuration/secret-management/) before adding it to your configuration.

**Type**: `string`

### [](#auth-user)`auth.user`

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

**Type**: `string`

### [](#auth-user_credentials_file)`auth.user_credentials_file`

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

**Type**: `string`

```yaml
# Examples:
user_credentials_file: ./user.creds
```

### [](#auth-user_jwt)`auth.user_jwt`

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

> ⚠️ **CAUTION**
>
> This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see [Manage Secrets](https://docs.redpanda.com/cloud-data-platform/develop/connect/configuration/secret-management/) before adding it to your configuration.

**Type**: `string`

### [](#auth-user_nkey_seed)`auth.user_nkey_seed`

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

> ⚠️ **CAUTION**
>
> This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see [Manage Secrets](https://docs.redpanda.com/cloud-data-platform/develop/connect/configuration/secret-management/) before adding it to your configuration.

**Type**: `string`

### [](#headers)`headers`

Explicit message headers to add to messages. This field supports [interpolation functions](https://docs.redpanda.com/cloud-data-platform/develop/connect/configuration/interpolation/#bloblang-queries).

**Type**: `string`

**Default**: `{}`

```yaml
# Examples:
headers:
  Content-Type: application/json
  Timestamp: ${!meta("Timestamp")}
```

### [](#inject_tracing_map)`inject_tracing_map`

EXPERIMENTAL: A [Bloblang mapping](https://docs.redpanda.com/cloud-data-platform/develop/connect/guides/bloblang/about/) 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.

**Type**: `string`

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

# ---

inject_tracing_map: root.meta.span = this
```

### [](#max_in_flight)`max_in_flight`

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

**Type**: `int`

**Default**: `1024`

### [](#max_reconnects)`max_reconnects`

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

**Type**: `int`

### [](#metadata)`metadata`

Determine which (if any) metadata values should be added to messages as headers.

**Type**: `object`

### [](#metadata-include_patterns)`metadata.include_patterns[]`

Provide a list of explicit metadata key regular expression (re2) patterns to match against.

**Type**: `array`

**Default**: `[]`

```yaml
# Examples:
include_patterns:
  - .*

# ---

include_patterns:
  - _timestamp_unix$
```

### [](#metadata-include_prefixes)`metadata.include_prefixes[]`

Provide a list of explicit metadata key prefixes to match against.

**Type**: `array`

**Default**: `[]`

```yaml
# Examples:
include_prefixes:
  - foo_
  - bar_

# ---

include_prefixes:
  - kafka_

# ---

include_prefixes:
  - content-
```

### [](#subject)`subject`

A subject to write to. This field supports [interpolation functions](https://docs.redpanda.com/cloud-data-platform/develop/connect/configuration/interpolation/#bloblang-queries).

**Type**: `string`

```yaml
# Examples:
subject: foo.bar.baz

# ---

subject: ${! meta("kafka_topic") }

# ---

subject: foo.${! json("meta.type") }
```

### [](#tls)`tls`

Custom TLS settings can be used to override system defaults.

**Type**: `object`

### [](#tls-client_certs)`tls.client_certs[]`

A list of client certificates to use. For each certificate either the fields `cert` and `key`, or `cert_file` and `key_file` should be specified, but not both.

**Type**: `object`

**Default**: `[]`

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

# ---

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

### [](#tls-client_certs-cert)`tls.client_certs[].cert`

A plain text certificate to use.

**Type**: `string`

**Default**: `""`

### [](#tls-client_certs-cert_file)`tls.client_certs[].cert_file`

The path of a certificate to use.

**Type**: `string`

**Default**: `""`

### [](#tls-client_certs-key)`tls.client_certs[].key`

A plain text certificate key to use.

> ⚠️ **CAUTION**
>
> This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see [Manage Secrets](https://docs.redpanda.com/cloud-data-platform/develop/connect/configuration/secret-management/) before adding it to your configuration.

**Type**: `string`

**Default**: `""`

### [](#tls-client_certs-key_file)`tls.client_certs[].key_file`

The path of a certificate key to use.

**Type**: `string`

**Default**: `""`

### [](#tls-client_certs-password)`tls.client_certs[].password`

A plain text password for when the private key is password encrypted in PKCS#1 or PKCS#8 format. The obsolete `pbeWithMD5AndDES-CBC` algorithm is not supported for the PKCS#8 format.

Because the obsolete pbeWithMD5AndDES-CBC algorithm does not authenticate the ciphertext, it is vulnerable to padding oracle attacks that can let an attacker recover the plaintext.

> ⚠️ **CAUTION**
>
> This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see [Manage Secrets](https://docs.redpanda.com/cloud-data-platform/develop/connect/configuration/secret-management/) before adding it to your configuration.

**Type**: `string`

**Default**: `""`

```yaml
# Examples:
password: foo

# ---

password: ${KEY_PASSWORD}
```

### [](#tls-enable_renegotiation)`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`.

**Type**: `bool`

**Default**: `false`

### [](#tls-enabled)`tls.enabled`

Whether custom TLS settings are enabled.

**Type**: `bool`

**Default**: `false`

### [](#tls-root_cas)`tls.root_cas`

An optional root certificate authority to use. This is a string, representing a certificate chain from the parent trusted root certificate, to possible intermediate signing certificates, to the host certificate.

> ⚠️ **CAUTION**
>
> This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see [Manage Secrets](https://docs.redpanda.com/cloud-data-platform/develop/connect/configuration/secret-management/) before adding it to your configuration.

**Type**: `string`

**Default**: `""`

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

### [](#tls-root_cas_file)`tls.root_cas_file`

An optional path of a root certificate authority file to use. This is a file, often with a .pem extension, containing a certificate chain from the parent trusted root certificate, to possible intermediate signing certificates, to the host certificate.

**Type**: `string`

**Default**: `""`

```yaml
# Examples:
root_cas_file: ./root_cas.pem
```

### [](#tls-skip_cert_verify)`tls.skip_cert_verify`

Whether to skip server side certificate verification.

**Type**: `bool`

**Default**: `false`

### [](#tls_handshake_first)`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.

**Type**: `bool`

**Default**: `false`

### [](#urls)`urls[]`

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

**Type**: `array`

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

# ---

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