Flower CLI reference

Basic Commands

flwr CLI

flwr

flwr is the Flower command line interface.

flwr [OPTIONS] COMMAND [ARGS]...

Options

--install-completion

Install completion for the current shell.

--show-completion

Show completion for the current shell, to copy it or customize the installation.

build

Build a Flower App into a Flower App Bundle (FAB).

You can run flwr build without any arguments to bundle the app located in the current directory. Alternatively, you can you can specify a path using the --app option to bundle an app located at the provided path. For example:

flwr build --app ./apps/flower-hello-world.

flwr build [OPTIONS]

Options

--app <app>

Path of the Flower App to bundle into a FAB

install

Install a Flower App Bundle.

It can be ran with a single FAB file argument:

flwr install ./target_project.fab

The target install directory can be specified with --flwr-dir:

flwr install ./target_project.fab --flwr-dir ./docs/flwr

This will install target_project to ./docs/flwr/. By default, flwr-dir is equal to:

  • $FLWR_HOME/ if $FLWR_HOME is defined

  • $XDG_DATA_HOME/.flwr/ if $XDG_DATA_HOME is defined

  • $HOME/.flwr/ in all other cases

flwr install [OPTIONS] source

Options

--flwr-dir <flwr_dir>

The desired install path.

Arguments

source

Optional argument

The source FAB file to install.

log

Get logs from a Flower project run.

flwr log [OPTIONS] RUN_ID [APP] [FEDERATION]

Options

--stream, --show

Flag to stream or print logs from the Flower run

Default:

True

Arguments

RUN_ID

Required argument

The Flower run ID to query

APP

Optional argument

Path of the Flower project to run

FEDERATION

Optional argument

Name of the federation to run the app on

login

Login to Flower SuperLink.

flwr login [OPTIONS] [APP] [FEDERATION]

Arguments

APP

Optional argument

Path of the Flower App to run.

FEDERATION

Optional argument

Name of the federation to login into.

ls

List the details of one provided run ID or all runs in a Flower federation.

The following details are displayed:

  • Run ID: Unique identifier for the run.

  • FAB: Name of the FAB associated with the run ({FAB_ID} (v{FAB_VERSION})).

  • Status: Current status of the run (pending, starting, running, finished).

  • Elapsed: Time elapsed since the run started (HH:MM:SS).

  • Created At: Timestamp when the run was created.

  • Running At: Timestamp when the run started running.

  • Finished At: Timestamp when the run finished.

All timestamps follow ISO 8601, UTC and are formatted as YYYY-MM-DD HH:MM:SSZ.

flwr ls [OPTIONS] [APP] [FEDERATION]

Options

--runs

List all runs

Default:

False

--run-id <run_id>

Specific run ID to display

--format <output_format>

Format output using ‘default’ view or ‘json’

Default:

'default'

Arguments

APP

Optional argument

Path of the Flower project

FEDERATION

Optional argument

Name of the federation

new

Create new Flower App.

flwr new [OPTIONS] [APP_NAME]

Options

--framework <framework>

The ML framework to use

Options:

PyTorch | TensorFlow | sklearn | HuggingFace | JAX | MLX | NumPy | FlowerTune | Flower Baseline

--username <username>

The Flower username of the author

Arguments

APP_NAME

Optional argument

The name of the Flower App

run

Run Flower App.

flwr run [OPTIONS] [APP] [FEDERATION]

Options

-c, --run-config <config_overrides>

Override configuration key-value pairs, should be of the format:

–run-config ‘key1=”value1” key2=”value2”’ –run-config ‘key3=”value3”’

Note that key1, key2, and key3 in this example need to exist inside the pyproject.toml in order to be properly overriden.

--stream

Use –stream with flwr run to display logs; logs are not streamed by default.

Default:

False

--format <output_format>

Format output using ‘default’ view or ‘json’

Default:

'default'

Arguments

APP

Optional argument

Path of the Flower App to run.

FEDERATION

Optional argument

Name of the federation to run the app on.

stop

Stop a run.

flwr stop [OPTIONS] RUN_ID [APP] [FEDERATION]

Options

--format <output_format>

Format output using ‘default’ view or ‘json’

Default:

'default'

Arguments

RUN_ID

Required argument

The Flower run ID to stop

APP

Optional argument

Path of the Flower project

FEDERATION

Optional argument

Name of the federation

flower-supernode

Start a Flower SuperNode

usage: flower-supernode [-h] [--insecure]
                        [--grpc-rere | --grpc-adapter | --rest]
                        [--root-certificates ROOT_CERT] [--server SERVER]
                        [--superlink SUPERLINK] [--max-retries MAX_RETRIES]
                        [--max-wait-time MAX_WAIT_TIME]
                        [--auth-supernode-private-key AUTH_SUPERNODE_PRIVATE_KEY]
                        [--auth-supernode-public-key AUTH_SUPERNODE_PUBLIC_KEY]
                        [--node-config NODE_CONFIG] [--flwr-dir FLWR_DIR]
                        [--isolation {subprocess,process}]
                        [--clientappio-api-address CLIENTAPPIO_API_ADDRESS]
                        [app]

Positional Arguments

app

(REMOVED) This argument is removed. The SuperNode now automatically uses the ClientApp delivered from the SuperLink, so there is no need to provide the app directory manually. This argument will be removed in a future version.

Named Arguments

--insecure

Run the client without HTTPS. By default, the client runs with HTTPS enabled. Use this flag only if you understand the risks.

Default: False

--grpc-rere

Use grpc-rere as a transport layer for the client.

Default: “grpc-rere”

--grpc-adapter

Use grpc-adapter as a transport layer for the client.

--rest

Use REST as a transport layer for the client.

--root-certificates

Specifies the path to the PEM-encoded root certificate file for establishing secure HTTPS connections.

--server

Server address

Default: “0.0.0.0:9092”

--superlink

SuperLink Fleet API (gRPC-rere) address (IPv4, IPv6, or a domain name)

Default: “0.0.0.0:9092”

--max-retries

The maximum number of times the client will try to reconnect to theSuperLink before giving up in case of a connection error. By default,it is set to None, meaning there is no limit to the number of tries.

--max-wait-time

The maximum duration before the client stops trying toconnect to the SuperLink in case of connection error. By default, itis set to None, meaning there is no limit to the total time.

--auth-supernode-private-key

The SuperNode’s private key (as a path str) to enable authentication.

--auth-supernode-public-key

The SuperNode’s public key (as a path str) to enable authentication.

--node-config

A space separated list of key/value pairs (separated by =) to configure the SuperNode. E.g. –node-config ‘key1=”value1” partition-id=0 num-partitions=100’

--flwr-dir
The path containing installed Flower Apps.

The default directory is:

  • $FLWR_HOME/ if $FLWR_HOME is defined

  • $XDG_DATA_HOME/.flwr/ if $XDG_DATA_HOME is defined

  • $HOME/.flwr/ in all other cases

--isolation

Possible choices: subprocess, process

Isolation mode when running a ClientApp (subprocess by default, possible values: subprocess, process). Use subprocess to configure SuperNode to run a ClientApp in a subprocess. Use process to indicate that a separate independent process gets created outside of SuperNode.

Default: “subprocess”

--clientappio-api-address

ClientAppIo API (gRPC) server address (IPv4, IPv6, or a domain name). By default, it is set to 0.0.0.0:9094.

Default: “0.0.0.0:9094”

Advanced Commands

flwr-serverapp

Run a Flower ServerApp

usage: flwr-serverapp [-h] [--serverappio-api-address SERVERAPPIO_API_ADDRESS]
                      [--run-once] [--flwr-dir FLWR_DIR] [--insecure]

Named Arguments

--serverappio-api-address

Address of SuperLink’s ServerAppIo API (IPv4, IPv6, or a domain name).By default, it is set to 127.0.0.1:9091.

Default: “127.0.0.1:9091”

--run-once

When set, this process will start a single ServerApp for a pending Run. If there is no pending Run, the process will exit.

Default: False

--flwr-dir
The path containing installed Flower Apps.

By default, this value is equal to:

  • $FLWR_HOME/ if $FLWR_HOME is defined

  • $XDG_DATA_HOME/.flwr/ if $XDG_DATA_HOME is defined

  • $HOME/.flwr/ in all other cases

--insecure

Run the server without HTTPS, regardless of whether certificate paths are provided. By default, the server runs with HTTPS enabled. Use this flag only if you understand the risks.

Default: False

flwr-clientapp

Run a Flower ClientApp

usage: flwr-clientapp [-h] [--clientappio-api-address CLIENTAPPIO_API_ADDRESS]
                      [--token TOKEN] [--flwr-dir FLWR_DIR] [--insecure]

Named Arguments

--clientappio-api-address

Address of SuperNode’s ClientAppIo API (IPv4, IPv6, or a domain name).By default, it is set to 127.0.0.1:9094.

Default: “127.0.0.1:9094”

--token

Unique token generated by SuperNode for each ClientApp execution

--flwr-dir
The path containing installed Flower Apps.

By default, this value is equal to:

  • $FLWR_HOME/ if $FLWR_HOME is defined

  • $XDG_DATA_HOME/.flwr/ if $XDG_DATA_HOME is defined

  • $HOME/.flwr/ in all other cases

--insecure

Run the server without HTTPS, regardless of whether certificate paths are provided. By default, the server runs with HTTPS enabled. Use this flag only if you understand the risks.

Default: False

Technical Commands

flower-simulation

Start a Flower simulation

usage: flower-simulation [-h] --app APP --num-supernodes NUM_SUPERNODES
                         [--run-config RUN_CONFIG] [--backend BACKEND]
                         [--backend-config BACKEND_CONFIG]
                         [--enable-tf-gpu-growth] [--verbose]
                         [--flwr-dir FLWR_DIR] [--run-id RUN_ID]

Named Arguments

--app

Path to a directory containing a FAB-like structure with a pyproject.toml.

--num-supernodes

Number of simulated SuperNodes.

--run-config

Override configuration key-value pairs.

--backend

Simulation backend that executes the ClientApp.

Default: “ray”

--backend-config

A JSON formatted stream, e.g ‘{“<keyA>”:<value>, “<keyB>”:<value>}’ to configure a backend. Values supported in <value> are those included by flwr.common.typing.ConfigsRecordValues.

Default: “{}”

--enable-tf-gpu-growth

Enables GPU growth on the main thread. This is desirable if you make use of a TensorFlow model on your ServerApp while having your ClientApp running on the same GPU. Without enabling this, you might encounter an out-of-memory error because TensorFlow by default allocates all GPU memory.Read more about how tf.config.experimental.set_memory_growth() works in the TensorFlow documentation: https://www.tensorflow.org/api/stable.

Default: False

--verbose

When unset, only INFO, WARNING and ERROR log messages will be shown. If set, DEBUG-level logs will be displayed.

Default: False

--flwr-dir
The path containing installed Flower Apps.

By default, this value is equal to:

  • $FLWR_HOME/ if $FLWR_HOME is defined

  • $XDG_DATA_HOME/.flwr/ if $XDG_DATA_HOME is defined

  • $HOME/.flwr/ in all other cases

--run-id

Sets the ID of the run started by the Simulation Engine.

Deprecated Commands

flower-server-app

Warning

Note that from version 1.13.0, flower-server-app is deprecated. Instead, you only need to execute flwr run to start the run.

flower-superexec

Warning

Note that from version 1.13.0, flower-superexec is deprecated. Instead, you only need to execute flower-superlink.