github.com/Jeffail/benthos/v3@v3.65.0/website/docs/components/inputs/mqtt.md

---
title: mqtt
type: input
status: stable
categories: ["Services"]
---

<!--
     THIS FILE IS AUTOGENERATED!

     To make changes please edit the contents of:
     lib/input/mqtt.go
-->

import Tabs from '@theme/Tabs';
import TabItem from '@theme/TabItem';


Subscribe to topics on MQTT brokers.


<Tabs defaultValue="common" values={[
  { label: 'Common', value: 'common', },
  { label: 'Advanced', value: 'advanced', },
]}>

<TabItem value="common">

```yaml
# Common config fields, showing default values
input:
  label: ""
  mqtt:
    urls:
      - tcp://localhost:1883
    topics:
      - benthos_topic
    client_id: benthos_input
    connect_timeout: 30s
```

</TabItem>
<TabItem value="advanced">

```yaml
# All config fields, showing default values
input:
  label: ""
  mqtt:
    urls:
      - tcp://localhost:1883
    topics:
      - benthos_topic
    client_id: benthos_input
    dynamic_client_id_suffix: ""
    qos: 1
    clean_session: true
    will:
      enabled: false
      qos: 0
      retained: false
      topic: ""
      payload: ""
    connect_timeout: 30s
    user: ""
    password: ""
    keepalive: 30
    tls:
      enabled: false
      skip_cert_verify: false
      enable_renegotiation: false
      root_cas: ""
      root_cas_file: ""
      client_certs: []
```

</TabItem>
</Tabs>

### Metadata

This input adds the following metadata fields to each message:

``` text
- mqtt_duplicate
- mqtt_qos
- mqtt_retained
- mqtt_topic
- mqtt_message_id
```

You can access these metadata fields using
[function interpolation](/docs/configuration/interpolation#metadata).

## Fields

### `urls`

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


Type: `array`  
Default: `["tcp://localhost:1883"]`  

### `topics`

A list of topics to consume from.


Type: `array`  
Default: `["benthos_topic"]`  

### `client_id`

An identifier for the client connection.


Type: `string`  
Default: `"benthos_input"`  

### `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 Benthos producers.


Type: `string`  
Default: `""`  

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


### `qos`

The level of delivery guarantee to enforce.


Type: `int`  
Default: `1`  
Options: `0`, `1`, `2`.

### `clean_session`

Set whether the connection is non-persistent.


Type: `bool`  
Default: `true`  

### `will`

Set last will message in case of Benthos failure


Type: `object`  

### `will.enabled`

Whether to enable last will messages.


Type: `bool`  
Default: `false`  

### `will.qos`

Set QoS for last will message.


Type: `int`  
Default: `0`  
Options: `0`, `1`, `2`.

### `will.retained`

Set retained for last will message.


Type: `bool`  
Default: `false`  

### `will.topic`

Set topic for last will message.


Type: `string`  
Default: `""`  

### `will.payload`

Set payload for last will message.


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"`  
Requires version 3.58.0 or newer  

```yaml
# Examples

connect_timeout: 1s

connect_timeout: 500ms
```

### `user`

A username to assume for the connection.


Type: `string`  
Default: `""`  

### `password`

A password to provide for the connection.


Type: `string`  
Default: `""`  

### `keepalive`

Max seconds of inactivity before a keepalive message is sent.


Type: `int`  
Default: `30`  

### `tls`

Custom TLS settings can be used to override system defaults.


Type: `object`  
Requires version 3.45.0 or newer  

### `tls.enabled`

Whether custom TLS settings are enabled.


Type: `bool`  
Default: `false`  

### `tls.skip_cert_verify`

Whether to skip server side certificate verification.


Type: `bool`  
Default: `false`  

### `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`  
Requires version 3.45.0 or newer  

### `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.


Type: `string`  
Default: `""`  

```yaml
# Examples

root_cas: |-
  -----BEGIN CERTIFICATE-----
  ...
  -----END CERTIFICATE-----
```

### `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.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: `array`  
Default: `[]`  

```yaml
# Examples

client_certs:
  - cert: foo
    key: bar

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

### `tls.client_certs[].cert`

A plain text certificate to use.


Type: `string`  
Default: `""`  

### `tls.client_certs[].key`

A plain text certificate key to use.


Type: `string`  
Default: `""`  

### `tls.client_certs[].cert_file`

The path to a certificate to use.


Type: `string`  
Default: `""`  

### `tls.client_certs[].key_file`

The path of a certificate key to use.


Type: `string`  
Default: `""`