codex-windows-gpt-5-6-dropdown-fix

name	codex-windows-gpt-5-6-dropdown-fix
description	Repair missing GPT-5.6 Sol, Terra, and Luna entries in the Windows Codex Desktop model picker when an API-key or third-party provider can already serve those models. Use for the verified Windows MSIX build in references/compatibility.json, before any task that modifies or reinstalls Codex Desktop.

Windows GPT-5.6 Dropdown Fix

Use this workflow only when the provider can already complete a small CLI request with the target model, but Codex Desktop does not show it in the picker.

Preconditions

• Confirm Windows, Codex Desktop, and the installed package version.
• Read references/compatibility.json. Stop if the installed version is absent.
• Confirm the provider supports every model that will be added to the catalog.
• Back up local Codex state before changing config.toml or replacing the package.
• Run package-changing work from external PowerShell, VS Code, or another agent environment. Do not reinstall the Codex Desktop process hosting this task.

Workflow

1. Run scripts/build-patched-msix.ps1 -Mode Check and require a patchable or already-patched result. Stop on every other result.
2. Use assets/model-catalog.26.707.example.json only when the backend list is missing GPT-5.6. Copy it to the user's Codex home, trim unsupported models, and set the top-level model_catalog_json path in user-level config.toml.
3. Explain that the catalog is a full replacement and this compatibility rule deliberately displays every catalog entry, including entries marked hidden.
4. Run scripts/build-patched-msix.ps1 -Mode Build -OutputRoot <large-local-path>. Inspect the generated local package and metadata before installation.
5. Obtain explicit confirmation before running -Mode Install. Require an elevated PowerShell session. Do not pass -AllowNonPreservingRemove unless a backup exists and the user understands the application-data risk.
6. Restart the exact OpenAI.Codex package, confirm the picker entries, and send a small request through each intended model. Keep provider URLs and logs local.

Rollback

Remove the model_catalog_json override, restore the official Store package, then remove the locally trusted signing certificate by the thumbprint recorded in local build-metadata.json. Do not commit that metadata or the certificate.

Resources

• scripts/patch-model-filter.ps1: exact-match, failure-closed asset patcher.
• scripts/build-patched-msix.ps1: staged preflight, build, and installation.
• references/compatibility.json: reviewed version-specific patch rules.
• assets/model-catalog.26.707.example.json: conditional catalog template.