Reconnecting loop + "Stream disconnected before completion: Transport error: network error: error decoding response body" when using GPT-5.2-Codex (high thinking) in VS Code & CLI

What version of Codex is running?

codex-cli 0.76.0. Bug found when using the Codex VS Code extension 0.4.56 (but reproducible via the Codex CLI)

What subscription do you have?

Plus

Which model were you using?

gpt-5.2-Codex

What platform is your computer?

Host: Microsoft Windows NT 10.0.26200.0 x64; Running on WSL: Linux 6.6.87.2-microsoft-standard-WSL2 x86_64 x86_64

What issue are you seeing?

When using the Codex VS Code extension (reproducible via the Codex CLI) with the GPT-5.2-Codex model in high thinking mode, requests eventually fail repeatedly with:

Reconnecting 1/5 …
…
Reconnecting 5/5 …
Stream disconnected before completion: Transport error: network error: error decoding response body

This behavior renders long-running or extended reasoning sessions unstable / unusable after a short period of successful operation. Similar patterns appear across environments and multiple recent reports.([GitHub](https://github.com/openai/codex/issues/8302?utm_source=chatgpt.com "stream disconnected before completion: Transport error ..."))

Key observations from my environment:

• VPN / proxy is stable and does not drop mid-session.

• Proxy IP does not change and other traffic (e.g., ChatGPT web) remains functional.

• The issue is not created by every request — it tends to occur after some usage in a session.

• In same session, simply switching:

1. model → works (e.g., GPT-5.1-Codex-Max),

1. thinking level (high → middle) → works,

indicates the failure correlates with the _combination of GPT-5.2-Codex + high settings + sustained inference_.

What steps can reproduce the bug?

1. Open VS Code with the Codex extension configured.

1. Connect successfully to a GPT-5.2-Codex (high thinking) session.

1. Issue multi-turn or multi-step prompts (e.g., coding tasks or extended conversation).

1. Observe connection output repeating:

``
Reconnecting 1/5 …
…
Reconnecting 5/5 …
Stream disconnected before completion: Transport error …
``

1. Confirm that switching either model or thinking mode in the same session can temporarily restore functionality.

What is the expected behavior?

• A stable, completing streaming response for each valid prompt without repeated reconnection attempts or premature disconnects.

• Session should either:

• stream the full response, or

• fail in a solid, meaningful error once per request, but not loop reconnect multiple times until eventual hard disconnect.

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Actual Behavior

• After some initial success, the session goes into a reconnect loop and ultimately fails with a “stream disconnected” transport error.

• This behavior often requires exiting and restarting Codex sessions, and impacts both editor workflows and CLI reconstructions.

• Behavior is reproducible across:

• Codex VS Code extension,

• Codex CLI runs,

• across multiple machines / OSes.([Reddit](https://www.reddit.com/r/OpenAI/comments/1o1w1nk/codex_cli_is_down_for_me_constant_disconnections/?utm_source=chatgpt.com "Codex CLI is down for me - Constant disconnections..."))

Additional information

Attempts & Workarounds Tried

• Verified network connectivity is stable and not dropping mid-session.

• Switched models within the same session (GPT-5.1-Codex-Max) — solves reconnection for that session.

• Switched thinking strength (high → middle) — also temporarily works.

• Restarting sessions / re-auth does not prevent eventual recurrence. (temporarily works at begin)

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Feedback

A simple attempt for /feedback: 019b3f46-a0c0-74f2-979e-9f72dffc2a12

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Hope will help :)

related issues I found:

• [#5679]
• [#8302]

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Note: I am not a native English speaker. This bug report was drafted with the assistance of ChatGPT. If there are parts that seem inconsistent or awkward, it may be due to edits I made when adapting the draft—please excuse any mistakes.