Model picker selection not applied to the live session until /reload when the same model id exists in the Command Code and OpenAI ChatGPT/Codex lanes #1098

Summary

Picking a model in the /model picker that lives in two lanes at once (Command Code gateway and the OpenAI ChatGPT/Codex BYOK lane) does not apply the selection to the running session. The picker closes and shows the confirmation status, but the session keeps routing through the previous lane until the user runs /reload. This is especially visible with the OpenAI models (gpt-5.6-luna, gpt-5.6-sol, gpt-6-luna, …), which exist in both the Command Code catalog and the ChatGPT/Codex provider lane.

Expected Behavior

Selecting a model with enter in /model should immediately apply it to the active session (rebuilding the harness session when the routing lane changes), without requiring a manual /reload.

Actual Behavior

After selecting a model that exists in both lanes, the UI shows the "Model set to …" status but the session keeps using the previous lane's route (verifiable via the · openai (byok) suffix missing from the transcript header, and by the routing behavior). Running /reload rebuilds the session from the persisted config and the new model + provider then apply correctly. Restarting the CLI also applies it, which confirms the persisted state is correct and only the live session is stale.

Steps to reproduce the issue

1. Connect an OpenAI ChatGPT/Codex account (/connect → OpenAI ChatGPT/Codex) with a ChatGPT Plus plan.
2. Start a session with a Command Code catalog model as the active model.
3. Open /model, select e.g. gpt-5.6-luna from the OpenAI lane, press enter.
4. The picker closes with "Model set to …" but the session keeps routing through the old lane (no · openai (byok) suffix in the header; requests don't hit the ChatGPT backend).
5. Run /reload → after the reload the model + provider apply and requests route through the ChatGPT subscription.

Command Code Version

1.88.2

Operating System

Windows

Terminal/IDE

Windows Terminal

Shell

cmd.exe / PowerShell 5.1

Session file (optional)

No response

Fix prompt (optional)

In the model-select handler, the harness session is only rebuilt when the selected model's lane provider differs from the currently configured provider (rebuildHarnessSession is gated on provider !== configuredProvider). When the same model id exists in both the Command Code catalog and a BYOK lane, resolving the pick to the bare catalog id makes the change look like a no-op, so neither the session rebuild nor the lane handoff happens and the live session keeps its old route. The pick should carry the lane/routeProvider through to the harness (like the route-aware path used elsewhere) so a cross-lane pick of an identical id still triggers the rebuild, or the rebuild condition should compare the resolved route (model + routeProvider), not just the provider field. Verify by selecting an OpenAI model from the Codex lane while a Command Code catalog model is active, then checking the header shows · openai (byok) without any reload.

Additional context

• Persisted state is written correctly on selection (config model / modelProvider update); only the running session is stale, which is why /reload or a restart "fixes" it.
• Related but distinct from chatgpt plan shows up in /model but the session doesn\'t run as the selected model #860 (that one is about the session not running as the selected model at all right after connecting; this one is about an already-connected session ignoring a lane-crossing model pick until reload).
• Environment notes: the BYOK OpenAI provider package was installed into the provider cache and the ChatGPT/Codex credential was present and valid while reproducing this; the bug reproduced consistently across several model switches between the two lanes.