OAuth login URL breaks when terminal is narrow (especially over SSH)

Bug

When running claude login in a narrow terminal (common when SSH'd into a remote server), the OAuth URL wraps with hard line breaks. When the user copies the URL — either manually or via the c to copy prompt — the line breaks are included, splitting parameter names like redirect_uri and code_challenge across lines. The OAuth server then rejects the request with errors like:

• Missing redirect_uri parameter
• Missing code_challenge parameter

Repro

1. SSH into a remote server with a typical ~80-column terminal
2. Run claude login
3. The generated URL is ~500+ characters and wraps across 3-4 lines
4. Copy the URL (manually or via c prompt) and paste into browser
5. OAuth fails because parameter names are broken by newlines

Why c to copy doesn't help over SSH

Over SSH there's no access to the local machine's clipboard, so the c shortcut either doesn't work or copies with the line breaks intact.

Suggested fixes

• Write the URL to a temp file and tell the user to cat or open it (this is what we did as a workaround and it worked immediately)
• Detect narrow terminals and automatically write the URL to a file
• Use a short-lived redirect/URL shortener for the auth URL
• At minimum, warn the user if the terminal width is too narrow for the URL

Environment

• Claude Code v2.1.76
• SSH session to Ubuntu server
• Terminal width ~80-120 columns
• macOS client -> Ubuntu remote

🤖 Generated with Claude Code