Creating a .netrc File for Earthdata Login

A .netrc file is a plain text configuration file used to securely store login credentials for automated authentication. When accessing NASA Earthdata resources, a .netrc file allows seamless authentication without being prompted for your Earthdata Login (EDL) username and password everytime.

This guide walks you through how to create and secure your .netrc file to store your EDL credentials.

Key Things to Know

The general .netrc format is:

machine urs.earthdata.nasa.gov
    login your_username
    password your_password

Example:

machine urs.earthdata.nasa.gov
    login NSIDCDAACUser
    password IloveNSIDCDAAC

Important: Never share your .netrc file. Keep this file private and never share it.

Set appropriate file permissions to prevent unauthorized access.
The .netrc file must be in your Home directory. Use these commands to find your HOME directory location:
- For UNIX systems:
```
echo $HOME
```
- For Windows systems:
```
echo %HOMEDRIVE%%HOMEPATH%
```
Create your .netrc file (or _netrc on Windows) in the directory indicated by the command output.

Instructions by Operating System

Unix/Linux/macOS

1. Open a command line terminal and use the following echo command to store your EDL credentials. Replace the placeholders with your actual login and password.

echo 'machine urs.earthdata.nasa.gov login your_username password your_password' >> ~/.netrc

2. Set file permissions to restrict access:

chmod 0600 ~/.netrc

This step is crucial. It makes the file readable and writable only by you. If the permissions are too permissive, many tools will refuse to use the file.

3. You can check the contents of your .netrc file

cat ~/.netrc

Windows

1. Open Notepad or any plain-text editor.

2. Enter the .netrc format shown above, replace the placeholders with your actual login and password.

3. Save the file as _netrc (with an underscore instead of a period) in your home directory.

4. Set file permissions:

Right-click _netrc file and choose Properties
Go to the Security tab → Click Edit
Remove access for all other users except your own account
Click Apply to save the changes.