Connect

mqtt

Pushes messages to an MQTT broker.

Introduced in version 4.37.0.

Common
Advanced

output:
  label: ""
  mqtt:
    urls: [] # No default (required)
    client_id: ""
    connect_timeout: 30s
    topic: "" # No default (required)
    qos: 1
    write_timeout: 3s
    retained: false
    max_in_flight: 64

output:
  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: []
    topic: "" # No default (required)
    qos: 1
    write_timeout: 3s
    retained: false
    retained_interpolated: "" # No default (optional)
    max_in_flight: 64

The topic field can be dynamically set using function interpolations described here. When sending batched messages these interpolations are performed per message part.

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.

Fields

`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.

Requires version 3.58.0 or later.

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

Option	Summary
`nanoid`	append a nanoid of length 21 characters

nanoid

append a nanoid of length 21 characters

`keepalive`

Max seconds of inactivity before a keepalive message is sent.

Type: int

Default: 30

`max_in_flight`

The maximum number of messages to have in flight at a given time. For outputs that send messages in batches, this limit applies to message batches. Increase this value to improve throughput.

Type: int

Default: 64

`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 Secrets.

Type: string

Default: ""

`qos`

The QoS value to set for each message. Has options 0, 1, 2.

Type: int

Default: 1

`retained`

Set message as retained on the topic.

Type: bool

Default: false

`retained_interpolated`

Override the value of retained with an interpolable value, this allows it to be dynamically set based on message contents. The value must resolve to either true or false.

This field supports interpolation functions.

Requires version 3.59.0 or later.

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

`topic`

The topic to publish messages to.

This field supports interpolation functions.

Type: 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: ""

`write_timeout`

The maximum amount of time to wait to write data before the attempt is abandoned.

Requires version 3.58.0 or later.

Type: string

Default: 3s

# Examples:
write_timeout: 1s

# ---

write_timeout: 500ms

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mqtt

Performance

Fields

client_id

connect_timeout

dynamic_client_id_suffix

keepalive

max_in_flight

password

qos

retained

retained_interpolated

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

topic

urls[]

user

will

will.enabled

will.payload

will.qos

will.retained

will.topic

write_timeout

`client_id`

`connect_timeout`

`dynamic_client_id_suffix`

`keepalive`

`max_in_flight`

`password`

`qos`

`retained`

`retained_interpolated`

`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`

`topic`

`urls[]`

`user`

`will`

`will.enabled`

`will.payload`

`will.qos`

`will.retained`

`will.topic`

`write_timeout`