shadow-call-intercept.md

Shadow Call Intercept

What are shadow calls?

Codex Desktop App makes background API calls using gpt-5.4-mini for internal helper tasks:

• Thread title generation — auto-generates 3-8 word titles after your first prompt
• Commit message generation — generates git commit messages
• Skill orchestration — internal orchestration turns

These calls happen independently of your selected main model and use reasoningEffort: low.

The problem

• Non-OpenAI providers (Bedrock, Azure, etc.) may not support bare gpt-5.4-mini, causing 404 errors
• Users have no control over which model handles these helper tasks
• Shadow calls consume API quota without user awareness

Related GitHub issues: #26288, #28741, #28821, #24208

Configuration

Via Dashboard UI

1. Open the opencodex dashboard
2. Find the "Shadow Call Intercept" panel
3. Toggle the switch to enable
4. Enter a replacement model (e.g., gpt-5.5)

Via config.json

{
  "shadowCallIntercept": {
    "enabled": true,
    "model": "gpt-5.5"
  }
}

Behavior

• When enabled, ALL requests with model IDs starting with gpt-5.4-mini are rewritten to the configured model
• Reasoning effort is forced to low (matching the original behavior)
• The original model ID is logged as shadowCallRewrittenFrom in request logs
• When disabled (default), no interception occurs

Warning

Enabling this redirects ALL gpt-5.4-mini requests. If you intentionally use gpt-5.4-mini for other tasks, those will also be redirected.