When using deepseek with openai-response in the Codex app, an error is encountered:

[lusile2024]

Client or integration

Codex App

Area

Proxy and routing

Summary

When using deepseek with openai-response in the Codex app, an error is encountered: The reasoning_text in the thinking mode must be passed back to the API.

Reproduction

1.ocx start
2.add deepseek with openai-response
3.ocx sync
4.codex desktop

Version

2.12.0

Operating system

windows 10

Provider and model

No response

Logs or error output

Screenshots and supporting files

No response

Redacted configuration

Checks

• I searched existing issues and documentation.
• I removed secrets, tokens, account details, request credentials, and personal data.

[coderabbitai]

⚠️ Possible Duplicate Issue(s)

• [Bug] DeepSeek V4 Flash Responses multi-tool continuation fails with reasoning_text 400 on 2.12.0 #1534

🔗 Related PRs

#906 - fix(deepseek): preserve Responses reasoning replay on continuations (#875) [open]
#1499 - fix(deepseek): keep parallel reasoning replay on continuation [open]

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[lidge-jun]

Closing as needs-info — diagnosing this requires a redacted wire capture showing the actual request/response exchange with the DeepSeek provider. If you can provide the capture (with secrets redacted), please reopen. 재현을 위한 wire capture가 필요하며, 현재 정보만으로는 진단이 어렵습니다.

[chenli1989]

@lusile2024 I encountered the same issue, and the following solution worked for me:
Adding the preserveResponsesReasoningContent property and enabling it within the configuration for the relevant provider resolves the issue. I hope this helps.