Login with ChatGPT

The login-with-chatgpt command allows you to authenticate with the Cosine CLI using your existing ChatGPT subscription. This feature enables direct routing to OpenAI’s Codex models, billing usage through your existing OpenAI account.

Supported Subscriptions

This authentication method works with:

Personal subscriptions: ChatGPT Plus and ChatGPT Pro
Organization subscriptions: ChatGPT Business and ChatGPT Enterprise

Usage

Interactive Browser Flow (Recommended)

Run the command and let it automatically open your browser:

cos login-with-chatgpt

Your browser will open to the OpenAI OAuth authorization page
Sign in with your OpenAI account (or select your organization)
Authorize Cosine CLI to access your account
You’ll be redirected back to confirm successful authentication

Manual Flow (No Browser)

If you prefer not to open a browser automatically or are in a headless environment:

cos login-with-chatgpt --no-browser

The CLI will display a URL for you to open manually
Complete the OAuth flow in your browser
Copy the final redirect URL from your browser’s address bar
Paste it back into the CLI prompt

How It Works

When you authenticate with login-with-chatgpt:

OAuth PKCE Flow: The CLI uses the OAuth 2.0 Authorization Code flow with PKCE for secure authentication
Token Storage: Your access token, refresh token, and account ID are securely stored in ~/.cosine/auth.openai.json with 0600 permissions
Automatic Refresh: When your access token nears expiration, the CLI automatically refreshes it using your refresh token
Direct Inference: Future cos commands use your OpenAI OAuth token for direct inference to OpenAI’s Codex models

Configuration

After login, your configuration is automatically updated:

[auth.openai]
auth_method = "oauth"

[config]
logged_in_with_openai = true

Switching Authentication Methods

The CLI supports multiple authentication methods. To switch between them:

Cosine Account: Use cos login to authenticate with your Cosine account
ChatGPT Subscription: Use cos login-with-chatgpt to use your OpenAI subscription

Troubleshooting

”No OpenAI OAuth tokens found”

If you see this error when running commands:

no OpenAI OAuth tokens found; run 'cos login-with-chatgpt'

Run the login command again to refresh your authentication.

Automatic Fallback

If your OpenAI OAuth tokens expire or become invalid, the CLI will automatically:

Display a warning message in the logs
Disable OpenAI OAuth authentication
Fall back to the default Cosine inference endpoint
Continue working without crashing

You can re-enable OpenAI OAuth by running:

cos login-with-chatgpt

State Mismatch Errors

If you encounter a “state mismatch” error during the manual flow:

Ensure you complete the OAuth flow promptly (state expires after 10 minutes)
Copy the complete redirect URL including all query parameters
Try the browser flow instead if issues persist

Token Refresh Failures

If token refresh fails:

Re-run cos login-with-chatgpt to obtain fresh tokens
Check your network connection
Verify your OpenAI subscription is active

Security

Tokens are stored with file permissions 0600 (readable only by your user)
PKCE (Proof Key for Code Exchange) protects against authorization code interception attacks
State parameters prevent CSRF attacks
No credentials are ever logged or transmitted to Cosine servers when using this auth method