The Flywheel Command-Line Interface (CLI) is a tool for uploading existing data into Flywheel and downloading data from Flywheel to work with offline. The Flywheel CLI is also required to start jobs and build gears. This article explains how to download and install the Flywheel CLI.

Step 1: Download

To download the Flywheel CLI:

Log in to Flywheel.
In the upper-right corner, select your account menu, and select Profile.
Go to the Download Flywheel CLI section,and select your computer's operating system.

A zip file with the following name is downloaded to your computer:

Linux: fw-linux_amd64.zip
OS X: fw-darwin_amd64.zip
Windows: fw-windows_amd64.zip

Step 2: Install

Linux and OS X

Open the Terminal app.
Unzip the file.
In Terminal, navigate to the Flywheel CLI. For example:

OS X
```
cd ~/Downloads/fw-darwin_amd64
```
Linux
```
cd ~/Downloads/fw-linux_amd64
```
(Optional) Enter this command to add the CLI to your PATH:
```
sudo mv ./fw /usr/local/bin
```
This makes it easier to access the Flywheel CLI later on. It is not required to add the Flywheel CLI to your PATH. If you do not to add it to your PATH, you must either enter the file path where fw resides in the commands below or run the commands from the same location as the Flywheel CLI.
Enter your password when prompted.

Windows

Open the Command Prompt app.
Unzip fw-windows_amd64.
(Optional) Enter the following command to add the Flywheel CLI to you PATH:
```
set PATH=%PATH%;c:\<pathToYourFlyweehlCLI>
```
For example:
```
set PATH=%PATH%;c:\Programs\fw.exe
```

This makes it easier to access the Flywheel CLI later on. It is not required to add the Flywheel CLI to your PATH. If you do not to add it to your PATH, you must either enter the file path where fw.exe resides in the commands below or run the commands from the same location as the Flywheel CLI.

Step 3: Generate an API key

To start using the CLI to interact with Flywheel, generate an API key.

On your Flywheel User Profile, go to the API Key section.
Click Generate API Key.

The API Key appears. This is specific to your Flywheel site. You may only have one active API key for a site at a time.

Step 4: Log in

Use your API key to log in to the CLI:

Copy your API Key.
In Terminal or Command Prompt, enter the following command:
```
fw login <yourapikey>
```
For example:
```
fw login university.flywheel.io:123456789abcde
```
The following message appears:
```
You are now logged in as <username>!
```

The Flywheel CLI is now installed. Learn more about how to start using the CLI.