invalid_request_error Failed to parse request body as json with error: Expected end of string, but instead reached end of data. LineNumber: 0 | BytePositionInLine:

What version of Codex CLI is running?

codex-cli 0.105.0

What subscription do you have?

Azure AI Foundry

Which model were you using?

gpt-5.3-codex

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64

What terminal emulator and version are you using (if applicable)?

Windows Terminal (PowerShell)

What issue are you seeing?

■ {
"error": {
"type": "invalid_request_error",
"message": "Failed to parse request body as json with error: Expected end of string, but instead reached end of data. LineNumber: 0 | BytePositionInLine: 89182."
}
}

<img width="1035" height="304" alt="Image" src="https://github.com/user-attachments/assets/ea1ddba1-83f1-47dc-98ba-66a6821962e6" />

What steps can reproduce the bug?

After a few seconds in planning mode with the new GPT-5.3-Codex model in Azure AI Foundry, I consistently get this error:

■ {
"error": {
"type": "invalid_request_error",
"message": "Failed to parse request body as json with error: Expected end of string, but instead reached end of data. LineNumber: 0 | BytePositionInLine: 89182."
}
}

<img width="1028" height="304" alt="Image" src="https://github.com/user-attachments/assets/ff98b751-365c-48fa-bca3-5c234ae977c1" />

At first it looks like it’s working, because it starts reading AGENTS.md and other files, but after a while it throws that error. The BytePositionInLine value changes on every attempt.

What is the expected behavior?

Planning mode executes successfully

Additional information

_No response_