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The Mojo🔥 command line interface.


mojo <command>
mojo [run-options] <path>
mojo [options]


The mojo CLI provides all the tools you need for Mojo development, such as commands to run, compile, and package Mojo code. A list of all commands are listed below, and you can learn more about each one by adding the --help option to the command (for example, mojo package --help).

However, you may omit the run and repl commands. That is, you can run a Mojo file by simply passing the filename to mojo:

mojo hello.mojo

And you can start a REPL session by running mojo with no commands.

To update Mojo to the latest version, use the modular tool:

modular update mojo

You can check your current version with mojo --version. For information about Mojo updates, see the Mojo changelog.


run — Builds and executes a Mojo file.

build — Builds an executable from a Mojo file.

repl — Launches the Mojo REPL.

debug — Launches the Mojo debugger using the command-line interface or an external editor.

package — Compiles a Mojo package.

format — Formats Mojo source files.

doc — Compiles docstrings from a Mojo file.

demangle — Demangles the given name.

test — Execute unit, integration, and documentation tests.


Diagnostic options​

--version, -v​

Prints the Mojo version and exits.

Common options​

--help, -h​

Displays help information.