[Bug] Anthropic API Error: Connection closed mid-response with Claude Opus

[imanamini]

Bug Description
Bug: API Error: Connection closed mid-response — persistent, not resolved by update, retry, or continue

I'm hitting "API Error: Connection closed mid-response. The response above may be incomplete." repeatedly and consistently when using Opus in Claude Code (terminal). It does not happen with Sonnet on the same setup.

Steps already taken, none resolved it:

• Updated to the latest Claude Code version via claude update
• Raised API_TIMEOUT_MS to 1200000
• Replying with "continue" after the error — the same error recurs shortly after, instead of completing the response

Frequency: happens on most Opus requests, especially longer/more involved ones.
Model affected: Opus (Sonnet works fine)
Environment: [fill in — macOS/Linux/WSL/Windows]
Claude Code version: 2.1.220
Network: [fill in — direct connection, VPN, or corporate proxy?]

This makes Opus effectively unusable for me in Claude Code right now.

Environment Info

• Platform: linux
• Terminal: gnome-terminal
• Version: 2.1.220
• Feedback ID: 6fff1ecc-f254-4c7d-af1a-d3e1d4166524

Errors

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