Codex app-server is the interface Codex uses to power rich clients (for example, the Codex VS Code extension). Use it when you want a deep integration inside your own product.
It mentions 'Inside your own product', but not sure if that means also your own commercial application.
By default, assume no. The lack of any official integration guide should be a clear sign. Even saying that you reverse-engineer Codex for apps to pretend to be Codex makes it clear that this is not an officially endorsed thing to do
Codex is Open Source though, so I wonder at what stage me adding features to Codex is different from me starting a new project and using the subscription.
But I believe OpenAI does let you use their subscription in third parties, so not an issue anyway.
Yes. You can build third party applications on top of codex app server. All open source. https://developers.openai.com/codex/app-server/
I think it's permissible. Zed uses it to power their Codex integration. OpenAI has been quite vocal about it.
By default, assume no. The lack of any official integration guide should be a clear sign. Even saying that you reverse-engineer Codex for apps to pretend to be Codex makes it clear that this is not an officially endorsed thing to do
Codex is Open Source though, so I wonder at what stage me adding features to Codex is different from me starting a new project and using the subscription.
But I believe OpenAI does let you use their subscription in third parties, so not an issue anyway.
Interested to know this too