[BUG] Claude Code silently continues when there is no internet connection instead of immediately notifying the user

• [x] I searched existing issues and didn't find a duplicate
• [x] This is a single bug report (not multiple issues combined)
• [x] I'm using the latest version of Claude Code

What's Wrong?

When Claude Code starts with no internet connection, it does not detect or report the connectivity issue. Instead, it appears to keep working — the spinner keeps going, tool calls seem to proceed, and there is no indication anything is wrong. The user wastes time waiting for output that will never arrive.

This is especially problematic on laptops where you open the lid, launch Claude Code, and Wi-Fi has not reconnected yet. The tool should fail fast and loud, not silently pretend everything is fine.

What Should Happen?

When Claude Code cannot reach the API (whether at startup or mid-session), it should:

1. Immediately surface a clear error: e.g., "No internet connection — unable to reach the API. Check your connection and try again."
2. Not continue spinning or showing progress indicators. No shimmy, no activity — just the error.
3. Optionally retry with backoff, but always with a visible message: "Retrying in 5s... (attempt 2/3)"
4. If retries fail, drop back to the prompt so the user can act (reconnect Wi-Fi, etc.).

Steps to Reproduce

1. Disconnect from the internet (turn off Wi-Fi, airplane mode, etc.)
2. Launch Claude Code (CLI or VS Code extension)
3. Send a prompt
4. Observe: Claude shows activity (spinner, partial progress) with no error message indicating there is no connectivity
5. The user has no way to know whether Claude is thinking or whether the network is down

Claude Model

Opus

Is this a regression?

Don't know

Environment

• Claude Code Version: 2.1.89 (CLI), 2.1.92 (VS Code extension)
• Platform: Max subscription
• Operating System: macOS 26.3.1 (Apple M2 Pro, 16 GB)
• Terminal/Shell: VS Code integrated terminal

Additional Information

The core ask: fail fast, fail loud. A 1-second connectivity check that surfaces "you are offline" is worth more than 60 seconds of silent spinning. Users should never have to wonder whether Claude is thinking or whether the network is down. This is table-stakes UX for any networked tool.