Expanded Codex support in the agent host does not work

Type: Bug

After enabling both chat.agentHost.codexAgent.enabled and chat.editor.codex.preferAgentHost, then signing into ChatGPT account through VSCode, the Codex Agents/Models are not available in the VSCode's native Chat panel nor in the Agents window.

The Chat pane still shows only free tier models and the Agents window still shows Upgrade blocker on both Codex and Claude models.

The only workaround is to manually initiate the Codex chat by keybinding a command:
```
{
"key": "ctrl+alt+shift+f12",
"command": "workbench.action.chat.openNewChatSessionInPlace.agent-host-codex",
"args": "sidebar"
}
```

After this, Codex models become available in both Chat sidebar as well as Agents window, but it will only stay that way for the current VSCode session. After a restart, the Codex models become inaccessible from the UI again.

VS Code version: Code 1.138.0 (7debcd0e2acdea1c52de81bf9ee1620444407dda, 2026-09-15T07:24:32Z)
OS version: Windows_NT x64 10.0.26200
Modes:

System Info

|Item|Value|
|---|---|
|CPUs|AMD Ryzen 9 3900X 12-Core Processor (24 x 3800)|
|GPU Status|2d_canvas: enabled
GPU0: VENDOR= 0x10de, DEVICE=0x2705 [NVIDIA GeForce RTX 4070 Ti SUPER], DRIVER_VENDOR=NVIDIA, DRIVER_VERSION=32.0.15.9649 *ACTIVE*
GPU1: VENDOR= 0x1414, DEVICE=0x008c [Microsoft Basic Render Driver], DRIVER_VERSION=10.0.26100.9278
Machine model name:
Machine model version:
direct_rendering_display_compositor: disabled_off_ok
gpu_compositing: enabled
multiple_raster_threads: enabled_on
opengl: enabled_on
rasterization: enabled
raw_draw: disabled_off_ok
skia_graphite: disabled_off
trees_in_viz: disabled_off
video_decode: enabled
video_encode: enabled
webgl: enabled
webgpu: enabled
webnn: disabled_off|
|Load (avg)|undefined|
|Memory (System)|63.91GB (45.40GB free)|
|Process Argv|--crash-reporter-id 7a6c2507-c44b-4e8f-8d06-918d5883f16a|
|Screen Reader|no|
|VM|0%|
Extensions (1)

Name|Identifier|Author|Version
---|---|---|---
Codex – OpenAI’s coding agent|openai.chatgpt|openai|26.908.40401