Cloud

mqtt

Subscribe to topics on MQTT brokers.

  • Common

  • Advanced

input:
  label: ""
  mqtt:
    urls: [] # No default (required)
    client_id: ""
    connect_timeout: 30s
    topics: [] # No default (required)
    auto_replay_nacks: true
input:
  label: ""
  mqtt:
    urls: [] # No default (required)
    client_id: ""
    dynamic_client_id_suffix: "" # No default (optional)
    connect_timeout: 30s
    will:
      enabled: false
      qos: 0
      retained: false
      topic: ""
      payload: ""
    user: ""
    password: ""
    keepalive: 30
    tls:
      enabled: false
      skip_cert_verify: false
      enable_renegotiation: false
      root_cas: ""
      root_cas_file: ""
      client_certs: []
    topics: [] # No default (required)
    qos: 1
    clean_session: true
    auto_replay_nacks: true

Metadata

This input adds the following metadata fields to each message:

  • mqtt_duplicate

  • mqtt_qos

  • mqtt_retained

  • mqtt_topic

  • mqtt_message_id

You can access these metadata fields using function interpolation.

Fields

auto_replay_nacks

Whether to automatically replay rejected messages (negative acknowledgements, or nacks) at the output level. If the cause of rejections persists, leaving this option enabled can result in back pressure.

Set auto_replay_nacks to false to delete rejected messages. Disabling auto replays can greatly improve memory efficiency of high throughput streams, as the original shape of the data is discarded immediately upon consumption and mutation.

Type: bool

Default: true

clean_session

Set whether the connection is non-persistent.

Type: bool

Default: true

client_id

The client identifier sent to the MQTT broker when connecting, which the broker uses to identify the client session. Use dynamic_client_id_suffix to give each run of the pipeline a unique identifier.

Type: string

Default: ""

connect_timeout

The maximum amount of time to wait in order to establish a connection before the attempt is abandoned.

Type: string

Default: 30s

# Examples:
connect_timeout: 1s

# ---

connect_timeout: 500ms

dynamic_client_id_suffix

Append a dynamically generated suffix to the specified client_id on each run of the pipeline. This can be useful when clustering Redpanda Connect producers.

Type: string

Option Summary

nanoid

append a nanoid of length 21 characters

keepalive

Max seconds of inactivity before a keepalive message is sent.

Type: int

Default: 30

password

A password to connect with.

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

Type: string

Default: ""

qos

The level of delivery guarantee to enforce. Has options 0, 1, 2.

Type: int

Default: 1

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 Manage Secrets before adding it to your configuration.

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 Manage Secrets before adding it to your configuration.

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.

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 Manage Secrets before adding it to your configuration.

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

topics[]

A list of topics to consume from.

Type: array<string>

urls[]

A list of URLs to connect to. Use the format scheme://host:port, where:

  • scheme is one of the following: tcp, ssl, ws

  • host is the IP address or hostname

  • port is the port on which the MQTT broker accepts connections

If an item in the list contains commas, it is expanded into multiple URLs.

Type: array<string>

# Examples:
urls:
  - "tcp://localhost:1883"

user

A username to connect with.

Type: string

Default: ""

will

Set last will message in case of Redpanda Connect failure

Type: object

will.enabled

Whether to enable last will messages.

Type: bool

Default: false

will.payload

Set payload for last will message.

Type: string

Default: ""

will.qos

Set QoS for last will message. Valid values are: 0, 1, 2.

Type: int

Default: 0

will.retained

Set retained for last will message.

Type: bool

Default: false

will.topic

Set topic for last will message.

Type: string

Default: ""