OpenAI oauth 5.2 codex model is not injecting system prompt for agent persona

[CarlosCommits]

Description

When using OpenAI 5.2, the agent persona/system prompt (and maybe the entire config?) is not being passed through correctly.

Plugins

none

OpenCode version

1.1.42

Steps to reproduce

1. Try using opencode with 5.2 codex OpenAI oauth model
2. Ask any agent "what agent are you"
3. will always respond with "I'm opencode, your coding assistant"
4. Repeat same steps with any other LLM model and you will get the correct identity answer.
5. When using 5.2 codex model, all agents function as default opencode default build agent it seems.

Screenshot and/or share link

I created a 'test' agent to demonstrate.

Here, 5.2 oauth model is used and does not inject agent persona:

Here, 5.2 Zen API is used and it does pick up/inject agent persona:

Here, GLM 4.7 Zen API is used and correctly injects agent config as well:

Operating System

Ubuntu - WSL

Terminal

Wezterm

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• GPT 5.2 Codex - Compaction happens way too early and context limit is wrong #11086: GPT 5.2 Codex - Compaction happens way too early and context limit is wrong

Both issues involve OpenAI's GPT 5.2 Codex model having configuration/behavior problems (agent persona injection in #11163 vs context limit miscalculation in #11086).

Feel free to ignore if this doesn't address your specific case.