codex - 💡(How to fix) Fix Improve subagent provider visibility [2 comments, 3 participants]

What feature would you like to see?

The Codex app currently makes provider selection and subagent provider behavior hard to control and hard to understand in the UI.

I would like three related improvements:

1. Add an easy provider picker in the Codex app UI for chat threads.

   • This should make it possible to switch a thread from one provider to another without editing TOML.
   • If switching providers invalidates or reduces the usefulness of cached thread content, that is acceptable, but the UI should warn the user clearly before the switch.

2. Add a global way to choose a different provider for spawned agents.

   • This should be supported in config.toml.
   • Even better, it should also be exposed in the Codex app settings UI.
   • This is useful because it often makes sense to keep the main thread on one provider while sending subagents to a cheaper provider or a local model.

3. Fix the Codex app UI so subagents show the correct effective provider/model.

   • Right now the subagent UI can show the provider/model of the calling agent even when the subagent is actually running on a different provider.
   • This makes provider debugging much harder and creates false confidence about what is being used.

Why this matters

Provider/model routing is now a real workflow concern:

• main agent on one provider
• subagents on a cheaper provider
• local models for some tasks
• remote frontier models only where needed

The app should support this explicitly instead of requiring low-level config work and log inspection.

Concrete example

I configured subagents to use Azure with gpt-5.4-mini while keeping the main agent on OpenAI.

The authoritative child session metadata recorded:

• model_provider = "azure"
• model = "gpt-5.4-mini"

But the spawned subagents self-reported and appeared in the UI as OpenAI / GPT-5.

That indicates the effective runtime configuration and the displayed provider/model are diverging.

Suggested behavior

• Thread-level provider picker in the app UI.
• Global default provider/model for subagents in config, plus an app settings surface for the same.
• Subagent UI should display the effective resolved provider/model of the spawned session, not inherit the parent thread display.
• If provider switching affects cache reuse or thread continuity, show an explicit warning before applying the change.

Additional information

This is partly a feature request and partly a correctness/UI bug:

• feature request: easier provider selection in app/settings
• correctness bug: subagent provider/model display does not match actual spawned-session metadata