[BUG] Claude Code VS Code extension 2.1.296, Remote (vscode-server) on Linux, model claude-opus-5-5

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

The agent hangs mid-task: a stream starts, then receives no more data, with no error,
no timeout and no retry. It waited 4+ minutes until I interrupted. Earlier turns in the
same session each finished in 1-5 s. This has happened in several sessions.

08:19:52.460 [API REQUEST] /v1/messages x-client-request-id=fdf4fbbb-88ac-4f0b-bd34-1b2e68ca1788
08:19:53.097 Stream started - received first chunk
08:19:53.098 [API:timing] first byte after 639ms
(no further log lines for this request)

Expected: a stalled stream is detected and retried, or an error is shown.

What Should Happen?

IT should just continue like normal, like it was all the time

Error Messages/Logs

08:19:52.460  [API REQUEST] /v1/messages x-client-request-id=fdf4fbbb-88ac-4f0b-bd34-1b2e68ca1788
08:19:53.097  Stream started - received first chunk
08:19:53.098  [API:timing] first byte after 639ms
(no further log lines for this request)

Steps to Reproduce

Steps to reproduce (intermittent, not deterministic):

1. VS Code with Remote (vscode-server) on Linux, Claude Code extension 2.1.296,

model claude-opus-5-5, permission mode auto, effort high (also happened on very high/max).

1. Start a long agentic task in a medium-sized repo (many Bash/Read tool calls in a row,

e.g. reading docs and source files before writing a plan).

1. After roughly 5-30 tool calls, one API request starts streaming (first chunk received)

and then receives no further data.

Frequency: 3+ times today across separate sessions, always mid-task, never at the start.
Context at the time: ~88k-138k tokens (well below the limit).

Actual: the UI shows the agent as working indefinitely; the log shows no stream end, no error,
no retry. Only Esc/interrupt recovers it.
Expected: a stalled stream is detected (idle timeout) and retried, or an error is shown.

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.296

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

Environment:

• Client OS: Windows (VS Code UI)
• Claude Code runs on: Linux (kernel 7.0.0-34-generic, Ubuntu) via VS Code Remote-SSH
• Extension: anthropic.claude-code 2.1.296 (native binary on the remote host)
• Network: home LAN behind a FRITZ!Box router