Flower is highly customizable. You can pass configuration options through the command line, configuration file, or environment variables. For a full list of options, see the Option Reference section.

Command line

Flower operates as a sub-command of Celery, allowing you to pass both Celery and Flower configuration options from the command line. The template for this is as follows

celery [celery options] flower [flower options]

Celery options should be specified after the celery command, while Flower options should be specified after the flower sub-command.

For example

$ celery --broker=redis:// flower --unix-socket=/tmp/flower.sock

See Celery Configuration reference for a comprehensive listing of all available settings and their default values.

Configuration file

Flower tries to load configuration from the file by default. You can override the name of the configuration file with the conf option. The configuration file is a simple Python file that contains key-value pairs:

# Set RabbitMQ management api
broker_api = 'http://guest:guest@localhost:15672/api/'

# Enable debug logging
logging = 'DEBUG'

Environment variables

Flower configuration options can also be passed through environment variables. All Flower options must be prefixed with FLOWER_. For example, to set the basic_auth option to foo:bar, you would set the FLOWER_BASIC_AUTH environment variable to foo:bar

export FLOWER_BASIC_AUTH=foo:bar
celery flower

Option Reference


Default: ‘’ (empty string)

Sets the address on which the Flower HTTP server should listen. The address may be either an IP address or a hostname. If a hostname is provided, the server will listen on all IP addresses associated with that name. To listen on all available interfaces, set the address to an empty string.


Listen on all available interfaces:

$ celery flower --address=''

Listen only on the loopback interface:

$ celery flower --address='localhost'

Listen on all IP addresses associated with ‘’:

$ celery flower --address=''


Default: ‘’ (empty string)

Enables authentication. auth is a regular expression of emails to grant access.

The auth option allows you to enable authentication in Flower. By default, the auth option is set to an empty string, indicating that authentication is disabled.

To enable authentication and restrict access to specific email addresses, set the auth option to a regular expression pattern that matches the desired email addresses. The auth option supports a basic regex syntax, including:

  • Single email: Use a single email address, such as
  • Wildcard: Use a wildcard pattern with .* to match multiple email addresses with the same domain, such as .*
  • List of emails: Use a list of emails separated by pipes (|), such as|

Please note that for security reasons, the auth option only supports a basic regex syntax and does not provide advanced regex features.

For more information and detailed usage examples, refer to the Authentication section of the Flower documentation.


Default: True

Enables automatic refresh for the Workers view. By default, the Workers view automatically refreshes at regular intervals to provide up-to-date information about the workers. Set this option to False to disable automatic refreshing.


Default: None

Enables HTTP Basic authentication. It accepts a comma-separated list of username:password pairs. Each pair represents a valid username and password combination for authentication.


Enable HTTP Basic authentication with multiple users:

$ celery flower --basic-auth="user1:password1,user2:password2"

See HTTP Basic Authentication for more information.


Default: None

The URL of the broker API used by Flower to retrieve information about queues.

Flower uses the RabbitMQ Management Plugin to gather information about queues. The broker_api option should be set to the URL of the RabbitMQ HTTP API, including user credentials if required.


$ celery flower broker-api="http://username:password@rabbitmq-server-name:15672/api/"


By default, the RabbitMQ Management Plugin is not enabled. To enable it, run the following command:

$ rabbitmq-plugins enable rabbitmq_management


The port number for RabbitMQ versions prior to 3.0 is 55672.

For more information refer to the RabbitMQ Management Plugin documentation.


Default: None

Sets the path to the ca_certs file containing a set of concatenated “certification authority” certificates.

The ca_certs file is used to validate certificates received from the other end of the connection. It contains a collection of trusted root certificates. Set the ca_certs option to the path of the ca_certs file. If not specified, certificate validation will not be performed.

For more information about certificate validation in Python, refer to the Python SSL documentation.


Default: None

Sets the path to the SSL certificate file.

The certfile option specifies the path to the SSL certificate file used for SSL/TLS encryption. The certificate file contains the public key certificate for the Flower server. If not specified, SSL/TLS encryption will not be used.



Sets the configuration file to be used by Flower.


$ celery flower --conf="./examples/"


Default: flower

Sets the database file to use if persistent mode is enabled.

If the persistent mode is enabled, the db option specifies the database file to be used by Flower for storing task results, events, or other persistent data.


$ celery flower --persistent=True --db="flower_db"


Default: False

Enables the debug mode


When debug mode is enabled, Flower may print sensitive information


Default: True

When enabled, Flower periodically sends Celery enable_events commands to all workers. Enabling Celery events allows Flower to receive real-time updates about task events from the Celery workers.

You can also enable events directly when running Celery workers by using the -E flag. For more information, refer to the Celery documentation:


Default: None

Modifies the default task formatting.

The format_task function allows to modify the default formatting of tasks. By defining the format_task function in the configuration file, you can customize the task object before it is displayed. The format_task function accepts a task object as a parameter and should return the modified version of the task.

This function is particularly useful for filtering out sensitive information or limiting display lengths of task arguments, kwargs, or results.

The example below shows how to filter arguments and limit display lengths:

from flower.utils.template import humanize

def format_task(task):
    task.args = humanize(task.args, length=10)
    task.result = humanize(task.result, length=20)
    return task


Default: 1000

Sets the timeout for the worker inspect commands in milliseconds.

Worker inspection involves retrieving information about the workers, such as their current status, tasks, and resource usage.


Default: None

Sets the path to the SSL key file.

The key file contains the private key corresponding to the SSL certificate. If not specified, or set to None, SSL/TLS encryption will not be used.


Default: 5000

Sets the maximum number of workers to keep in memory


Default: 100000

Sets the maximum number of tasks to keep in memory


Default: False

Enables showing time relative to the page refresh time in a more human-readable format.

When enabled, timestamps will be shown as relative time such as “2 minutes ago” or “1 hour ago” instead of the exact timestamp.


Default: False

Enables persistent mode in Flower.

When persistent mode is enabled, Flower saves its current state and reloads it upon restart. This ensures that Flower retains its state and configuration across restarts. Flower stores its state in a database file specified by the db option.


Default: 5555

Sets the port number for running the Flower HTTP server.


Default: 0

Sets the interval for saving the Flower state.

Flower state includes information about workers, tasks. The state is saved periodically to ensure data persistence and recovery upon restart.

By default, periodic saving is disabled. Flower will not automatically save its state at regular intervals. If you want to enable periodic state saving, set the state_save_interval option to a positive integer value representing the interval in milliseconds.


Default: False

Enables support for X-Real-Ip and X-Scheme headers.

The xheaders option allows Flower to enable support for X-Real-Ip and X-Scheme headers. These headers are commonly used in proxy or load balancer configurations to preserve the original client IP address and scheme.


Default: name,uuid,state,args,kwargs,result,received,started,runtime,worker

Specifies the list of comma-delimited columns to display on the /tasks page.

The tasks_columns option allows you to customize the columns displayed on the /tasks page in Flower. By default, the specified columns are: name, uuid, state, args, kwargs, result, received, started, runtime, and worker.

Available columns are:

  • name
  • uuid
  • state
  • args
  • kwargs
  • result
  • received
  • started
  • runtime
  • worker
  • retries
  • revoked
  • exception
  • expires
  • eta


$ celery flower --tasks-columns='name,uuid,state,args,kwargs,result,received,started,runtime,worker,retries,revoked,exception,expires,eta'

In the above example, all available columns are displayed.


Default: ‘’ (empty string)

Enables deploying Flower on a non-root URL.

The url_prefix option allows you to deploy Flower on a non-root URL. By default, Flower is deployed on the root URL. However, if you need to run Flower on a specific path, such as, you can specify the desired URL prefix using the url_prefix option.


Default: ‘’ (empty string)

Runs Flower using a UNIX socket file.

The unix_socket option allows you to run Flower using a UNIX socket file instead of a network port. By default, the unix_socket option is set to an empty string, indicating that Flower should not use a UNIX socket.

To run Flower using a UNIX socket file, set the unix_socket option to the desired path of the UNIX socket file. Flower will then bind to the specified socket file instead of a network port.


$ celery flower --unix-socket='/var/run/flower.sock'


Default: None

Sets the authentication provider for Flower.

The auth_provider option allows you to set the authentication provider for Flower. By default, the auth_provider option is set to None, indicating that no authentication provider is configured.

To enable authentication and specify an authentication provider, set the auth_provider option to one of the following values:

  • Google flower.views.auth.GoogleAuth2LoginHandler
  • GitHub flower.views.auth.GithubLoginHandler
  • GitLab flower.views.auth.GitLabLoginHandler
  • Okta flower.views.auth.OktaLoginHandler

See also Authentication for usage examples


Default: None

Time (in seconds) after which offline workers are automatically removed from the Workers view. By default, offline workers will remain on the dashboard indefinitely.


Default: ‘Histogram.DEFAULT_BUCKETS’ (default prometheus buckets)

Sets the task runtime latency buckets.

You can provide the buckets value as a comma-separated list of values.


$ celery flower --task-runtime-metric-buckets=1,5,10,inf

The buckets represent the upper bounds of the latency intervals. You can specify them as integer or float values. The inf value represents positive infinity, indicating that the last bucket captures all values greater than or equal to the previous bucket.


Default: None

Sets the OAuth 2.0 key (client ID) issued by the OAuth 2.0 provider

oauth2_key option should be used with auth, auth_provider, oauth2_redirect_uri and oauth2_secret options.


Default: None

Sets the OAuth 2.0 secret issued by the OAuth 2.0 provider

oauth2_secret option should be used with auth, auth_provider, oauth2_redirect_uri and oauth2_key options.


Default: None

Sets the URI to which an OAuth 2.0 server redirects the user after successful authentication and authorization.

oauth2_redirect_uri option should be used with auth, auth_provider, oauth2_key and oauth2_secret options.