gemini-cli/docs/cli/authentication.md

Authentication Setup

The Gemini CLI requires you to authenticate with Google's AI services. On initial startup you'll need to configure one of the following authentication methods:

1. Login with Google (Gemini Code Assist):

   • Use this option to log in with the standard, free account you use for services like Gmail, Google Photos, and Google Drive for personal use (e.g. your-name@gmail.com).
   • During initial startup, Gemini CLI will direct you to a webpage for authentication. Once authenticated, your credentials will be cached locally so the web login can be skipped on subsequent runs.
   • Note that the web login must be done in a browser that can communicate with the machine Gemini CLI is being run from. (Specifically, the browser will be redirected to a localhost url that Gemini CLI will be listening on).

2. Gemini API key:

   • Obtain your API key from Google AI Studio: https://aistudio.google.com/app/apikey
   • Set the GEMINI_API_KEY environment variable. In the following methods, replace YOUR_GEMINI_API_KEY with the API key you obtained from Google AI Studio:
     • You can temporarily set the environment variable in your current shell session using the following command:

       export GEMINI_API_KEY="YOUR_GEMINI_API_KEY"
       

     • For repeated use, you can add the environment variable to your .env file (located in the project directory or user home directory) or your shell's configuration file (like ~/.bashrc, ~/.zshrc, or ~/.profile). For example, the following command adds the environment variable to a ~/.bashrc file:

       echo 'export GEMINI_API_KEY="YOUR_GEMINI_API_KEY"' >> ~/.bashrc
       source ~/.bashrc
       

3. Login with Google Workspace

   • Use this option to log in with the Google Workspace Accounts. This is a paid service for businesses and organizations that provides a suite of productivity tools, including a custom email domain (e.g. your-name@your-company.com), enhanced security features, and administrative controls. These accounts are often managed by an employer or school.
     • Google Workspace Account must configure a Google Cloud Project Id to use. You can temporarily set the environment variable in your current shell session using the following command:

     export GOOGLE_CLOUD_PROJECT_ID="YOUR_PROJECT_ID"
     

     • For repeated use, you can add the environment variable to your .env file (located in the project directory or user home directory) or your shell's configuration file (like ~/.bashrc, ~/.zshrc, or ~/.profile). For example, the following command adds the environment variable to a ~/.bashrc file:

     echo 'export GOOGLE_CLOUD_PROJECT_ID="YOUR_PROJECT_ID"' >> ~/.bashrc
     source ~/.bashrc
     

   • During startup, Gemini CLI will direct you to a webpage for authentication. Once authenticated, your credentials will be cached locally so the web login can be skipped on subsequent runs.
   • Note that the web login must be done in a browser that can communicate with the machine Gemini CLI is being run from. (Specifically, the browser will be redirected to a localhost url that Gemini CLI will be listening on).

4. Vertex AI:

   • If not using express mode:
     • Ensure you have a Google Cloud project and have enabled the Vertex AI API.
     • Set up Application Default Credentials (ADC), using the following command:

       gcloud auth application-default login
       

       For more information, see Set up Application Default Credentials for Google Cloud.
     • Set the GOOGLE_CLOUD_PROJECT, GOOGLE_CLOUD_LOCATION, and GOOGLE_GENAI_USE_VERTEXAI environment variables. In the following methods, replace YOUR_PROJECT_ID and YOUR_PROJECT_LOCATION with the relevant values for your project:
       • You can temporarily set these environment variables in your current shell session using the following commands:

         export GOOGLE_CLOUD_PROJECT="YOUR_PROJECT_ID"
         export GOOGLE_CLOUD_LOCATION="YOUR_PROJECT_LOCATION" # e.g., us-central1
         export GOOGLE_GENAI_USE_VERTEXAI=true
         

       • For repeated use, you can add the environment variables to your .env file (located in the project directory or user home directory) or your shell's configuration file (like ~/.bashrc, ~/.zshrc, or ~/.profile). For example, the following commands adds the environment variables to a ~/.bashrc file:

         echo 'export GOOGLE_CLOUD_PROJECT="YOUR_PROJECT_ID"' >> ~/.bashrc
         echo 'export GOOGLE_CLOUD_LOCATION="YOUR_PROJECT_LOCATION"' >> ~/.bashrc
         echo 'export GOOGLE_GENAI_USE_VERTEXAI=true' >> ~/.bashrc
         source ~/.bashrc
         

   • If using express mode:
     • Set the GOOGLE_API_KEY environment variables. In the following methods, replace YOUR_GOOGLE_API_KEY with your Vertex AI API key provided by express mode:
       • You can temporarily set these environment variables in your current shell session using the following commands:

         export GOOGLE_API_KEY="YOUR_GOOGLE_API_KEY"
         export GOOGLE_GENAI_USE_VERTEXAI=true
         

       • For repeated use, you can add the environment variables to your .env file (located in the project directory or user home directory) or your shell's configuration file (like ~/.bashrc, ~/.zshrc, or ~/.profile). For example, the following commands adds the environment variables to a ~/.bashrc file:

         echo 'export GOOGLE_API_KEY="YOUR_GOOGLE_API_KEY"' >> ~/.bashrc
         echo 'export GOOGLE_GENAI_USE_VERTEXAI=true' >> ~/.bashrc
         source ~/.bashrc