The DFINITY command-line execution environment (dfx) is the primary tool for creating, deploying, and managing the applications you develop for the Internet Computer blockchain.

Use the dfx parent command with flags and subcommands to specify the operations you want to perform with or without optional arguments.

Basic usage

dfx [option] [subcommand] [flag]


You can use the following optional flags with the dfx parent command or with any of the dfx subcommands.

Flag Description

-h, --help

Displays usage information.

-q`, --quiet

Suppresses informational messages.

-v, --verbose

Displays detailed information about operations.

-V, --version

Displays version information.


You can use the following options with the dfx command.

Option Description

--identity <identity>

Specifies the user identity to use when running a command.

--logfile <logfile>

Writes log file messages to the specified log file name if you use the --log file logging option.

--log <logmode>

Specifies the logging mode to use. + You can set the log mode to one of the following:

- stderr to log messages to the standard error facility.

- tee to write messages to both standard output and to a specified file name.

- file to write messages to a specified file name.

The default logging mode is stderr.


Use the following subcommands to specify the operation you want to perform or to view usage information for a specific command.

For reference information and examples, select an appropriate subcommand.

Command Description


Starts the bootstrap server you want to use to serve front-end assets for your project.


Builds canister output from the source code in your project.


Manages the dfx cache on the local computer.


Manages canisters deployed on a network replica.


Sets or changes configuration options for your current project.


Deploys all or a specific canister from the code in your project. By default, all canisters are deployed.


Displays usage information for a specified subcommand.


Enables you to create and manage the identities used to communicate with the Internet Computer network.


Enables you to interact with accounts in the ledger canister running on the Internet Computer.


Creates a new project.


Sends a response request to a specified Internet Computer network to determine network connectivity. If the connection is successful, the Internet Computer replies with its status.


Starts a local network replica process.


Starts the local network replica and a web server for the current project.


Stops the local network replica.


Upgrades the version of dfx installed on the local computer to the latest version available.

dfx wallet

Enables you to manage cycles, controllers, custodians, and addresses for the default cycles wallet associated with the currently-selected identity.


You can use the dfx parent command to display usage information or version information. For example, to display information about the version of dfx you currently have installed, you can run the following command:

dfx --version

To view usage information for a specific subcommand, specify the subcommand and the --help flag. For example, to see usage information for dfx build, you can run the following command:

dfx build --help

Using logging options

You can use the --verbose and --quiet flags to increment or decrement the logging level. If you don’t specify any logging level, CRITICAL, ERROR, WARNING, and INFO messages are logged by default. Specifying one verbose flag (-v) increases the log level to include DEBUG messages. Specifying two verbose flags (-vv)increases the logging level to include both DEBUG and TRACE messages.

Adding a --quiet flag decreases the logging level. For example, to remove all messages, you can run a command similar the following:

dfx -qqqq build

Keep in mind that using TRACE level logging (--vv) generates a lot of log messages that can affect performance and should only be used when required for troubleshooting or analysis.

To output log messages to a file named newlog.txt and display the messages on your terminal when creating a new project, you can run a command similar to the following:

dfx --log tee --logfile newlog.txt new hello_world

Specifying a user identity

If you create user identities with the dfx identity new command, you can then use the --identity comment-line option to change the user context when running other dfx commands.

In the most common use case, you use the --identity option to call specific canister functions to test access controls for specific operations.

For example, you might want to test whether the devops user identity can call the modify_profile function for the accounts canister by running the following command:

dfx --identity devops canister call accounts modify_profile '("Kris Smith")'