> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/router-for-me/CLIProxyAPI/llms.txt
> Use this file to discover all available pages before exploring further.

# Antigravity OAuth

> Authenticate with Antigravity using OAuth 2.0

## Overview

Antigravity authentication enables access to Antigravity's AI services through OAuth 2.0. The CLI Proxy API handles the complete OAuth flow with automatic project discovery and token management.

## Prerequisites

Before authenticating with Antigravity, ensure you have:

* An Antigravity account with API access
* CLIProxyAPI server installed and configured
* A web browser for OAuth authentication (or use `-no-browser` flag)
* Network access to Antigravity's authentication servers

## Authentication

<Steps>
  <Step title="Start the login process">
    Run the following command to initiate Antigravity OAuth:

    ```bash theme={null}
    ./CLIProxyAPI -antigravity-login
    ```

    This will:

    * Start a local OAuth callback server
    * Open your default web browser automatically
    * Navigate to Antigravity's OAuth authorization page
  </Step>

  <Step title="Complete OAuth authorization">
    In the browser window:

    1. Sign in to your Antigravity account
    2. Review the requested permissions
    3. Click "Authorize" or "Allow" to grant access
    4. Wait for the automatic redirect to the callback server
  </Step>

  <Step title="Automatic project discovery">
    After OAuth completes, the CLI automatically:

    * Exchanges the authorization code for access tokens
    * Discovers your Antigravity project ID
    * Saves tokens and project metadata
    * Displays your authenticated account label
  </Step>

  <Step title="Confirmation">
    After successful authentication:

    ```
    Authentication saved to /path/to/auth/antigravity-<identifier>.json
    Authenticated as <your-account-label>
    Antigravity authentication successful!
    ```
  </Step>
</Steps>

<Note>
  Antigravity authentication includes automatic project ID discovery, similar to Google Gemini's auto-discovery mode. No manual project selection is required.
</Note>

## Advanced Options

### Manual Browser Authentication

If you're on a headless server or the browser doesn't open automatically:

```bash theme={null}
./CLIProxyAPI -antigravity-login -no-browser
```

The CLI will display:

```
Please visit this URL to authenticate:
https://antigravity.example.com/oauth/authorize?client_id=...
```

Open the URL manually in a browser on any device and complete the OAuth flow.

### Custom OAuth Callback Port

To use a specific port for the OAuth callback server:

```bash theme={null}
./CLIProxyAPI -antigravity-login -oauth-callback-port 9000
```

<Tip>
  Use a custom callback port if:

  * The default port is already in use
  * Your firewall blocks the default port
  * You're running multiple CLI instances
  * You need to match specific network policies
</Tip>

### Combined Options

You can combine flags for specific scenarios:

```bash theme={null}
# Headless server with custom port
./CLIProxyAPI -antigravity-login -no-browser -oauth-callback-port 8888
```

## Configuration

### Token Storage Location

Authentication tokens are stored in the configured auth directory:

* Default location: Set via `-auth-dir` flag or in config file
* Filename format: `antigravity-<identifier>-<timestamp>.json`
* Example: `antigravity-user-1234567890.json`

### Token Contents

The stored token file contains:

* OAuth 2.0 access token
* Refresh token (if provided by Antigravity)
* Token type and expiration timestamp
* Account identifier/label
* Auto-discovered project ID
* Authentication metadata

### Project ID Discovery

Antigravity authentication automatically discovers your project ID:

* No manual project selection required
* Similar to Gemini's Google One mode
* Project ID is fetched from your account metadata
* Stored in the token file for future use

This streamlines the authentication process compared to providers requiring manual project configuration.

### Multiple Accounts

You can authenticate with multiple Antigravity accounts:

```bash theme={null}
# First account
./CLIProxyAPI -antigravity-login

# Second account (after first completes)
./CLIProxyAPI -antigravity-login
```

Each account:

* Creates a separate token file
* Has its own project ID
* Is automatically loaded by the server
* Participates in credential rotation

Benefits of multiple accounts:

* Higher effective rate limits
* Load balancing across credentials
* Redundancy if one account has issues
* Separate billing/usage tracking

## Verification

To verify your authentication is working:

<Steps>
  <Step title="Check token file exists">
    ```bash theme={null}
    ls -la /path/to/auth-dir/antigravity-*.json
    ```

    You should see your Antigravity token file(s) listed.
  </Step>

  <Step title="Verify account label">
    During authentication, note the account label displayed:

    ```
    Authenticated as <your-account-label>
    ```

    This confirms which Antigravity account was authenticated.
  </Step>

  <Step title="Start the server">
    ```bash theme={null}
    ./CLIProxyAPI
    ```

    The server will:

    * Automatically discover Antigravity token files
    * Load credentials into the credential pool
    * Log successful credential registration
  </Step>

  <Step title="Make a test API request">
    Send a request to test Antigravity access:

    ```bash theme={null}
    curl http://localhost:8080/v1/chat/completions \
      -H "Content-Type: application/json" \
      -d '{
        "model": "antigravity-model",
        "messages": [{"role": "user", "content": "Hello!"}]
      }'
    ```
  </Step>
</Steps>

## Troubleshooting

### Browser doesn't open automatically

**Solution:** Use the `-no-browser` flag:

```bash theme={null}
./CLIProxyAPI -antigravity-login -no-browser
```

Then manually open the displayed URL in your browser.

### OAuth callback timeout

**Cause:** Authorization wasn't completed within the timeout period.

**Solution:**

* Complete the OAuth flow more quickly
* Check if your firewall blocks the callback port
* Ensure localhost/127.0.0.1 is accessible
* Try a different callback port with `-oauth-callback-port`

### "Authentication failed" error

**Possible causes:**

* Invalid authorization code
* Network connectivity issues
* Antigravity service outage
* Account permissions insufficient

**Solution:**

1. Check your network connection
2. Verify Antigravity services are operational
3. Ensure your account has API access enabled
4. Try authenticating again
5. Check server logs for detailed error messages

### Project ID discovery failed

**Cause:** Unable to fetch project ID from Antigravity.

**Solution:**

* Verify your account is properly set up
* Check if your account has projects configured
* Contact Antigravity support if the issue persists
* Review server logs for specific error details

### Port already in use

**Cause:** The OAuth callback port is occupied by another service.

**Solution:** Use a custom callback port:

```bash theme={null}
./CLIProxyAPI -antigravity-login -oauth-callback-port 9001
```

### Token not saving

**Cause:** Permission issues with the auth directory.

**Solution:**

```bash theme={null}
# Create directory if missing
mkdir -p /path/to/auth-dir

# Fix permissions
chmod 755 /path/to/auth-dir

# Verify writable
touch /path/to/auth-dir/test && rm /path/to/auth-dir/test
```

### Wrong account authenticated

**Cause:** Signed into different Antigravity account in browser.

**Solution:**

1. Sign out of the current account in your browser
2. Clear browser cookies for Antigravity
3. Run `-antigravity-login` again
4. Sign in with the correct account
5. Complete authorization

### Account label not displayed

**Cause:** Account metadata not available in OAuth response.

**Solution:**

* This is informational only - authentication still works
* Check the token file for account identifier
* Contact Antigravity support if you need label customization

## Token Refresh

Antigravity tokens are automatically refreshed by the server:

* The server monitors token expiration timestamps
* Refresh tokens (if provided) are used to obtain new access tokens
* Refreshed tokens are saved back to the auth directory
* No manual intervention required

If refresh fails:

* Check server logs for specific errors
* Ensure network connectivity to Antigravity
* Re-authenticate if tokens are invalid or expired

## Re-authentication

To re-authenticate an Antigravity account:

1. Delete the existing token file:
   ```bash theme={null}
   rm /path/to/auth-dir/antigravity-*.json
   ```

2. Run the login command again:
   ```bash theme={null}
   ./CLIProxyAPI -antigravity-login
   ```

3. Complete the OAuth flow again

4. New tokens and project ID will be saved

<Tip>
  Re-authentication is useful when:

  * Tokens expire and can't be refreshed
  * You need to update permissions
  * Your Antigravity account changes
  * You want to switch to a different account
</Tip>

## Security Best Practices

* **Never share token files** - They contain full account access credentials
* **Use restrictive permissions** - Keep auth directory at `755` and token files at `600`
* **Rotate credentials regularly** - Re-authenticate periodically for security
* **Monitor usage** - Check server logs for unusual authentication activity
* **Secure your auth directory** - Back up tokens securely, encrypt if storing remotely
* **Validate OAuth redirects** - Don't manually modify OAuth URLs or parameters

<Warning>
  Your Antigravity token files provide full access to your account and API services. Protect them as you would passwords or API keys.
</Warning>

## Project Management

Unlike other providers, Antigravity handles project management automatically:

* **No manual selection** - Project ID is auto-discovered
* **Single project per account** - Each authenticated account has one project
* **Automatic association** - Project ID is linked to your account
* **Transparent to users** - No project configuration needed

If you need to use a different project:

1. Create/switch to a different Antigravity account
2. Authenticate that account separately
3. Each account brings its own project

## Related Resources

* [Antigravity API Documentation](https://docs.antigravity.example.com/)
* [OAuth 2.0 Specification](https://oauth.net/2/)
* [Configuration Guide](/configuration/server)