Apus uses one provider id, openai, for both direct API-key auth and ChatGPT/Codex subscription auth. openai/* is the canonical model route. For embedded agent turns with runtime policy unset or auto, OpenAI's route facts decide whether Apus may select the bundled Codex app-server runtime implicitly. The openai/* prefix alone does not select a runtime.

OpenAI explicitly supports subscription OAuth usage in external tools and workflows like Apus.

This page is an index. OpenAI is documented on nine pages, one per reader job. Open the page that matches your task.

Page Read it when
OpenAI setup You are connecting an account: the API-key and Codex subscription paths, route summaries, OAuth recovery, and the long-context opt-in.
OpenAI authentication Choose Codex login, an API key, or SIWC based on model access, plugins, usage tracking, and permissions.
OpenAI models You are choosing a model ref: the quick-choice table, GPT-6 Astra, Sol, Luna, and the GPT-5.6 tiers.
OpenAI runtimes and Codex auth You need to know which runtime runs an openai/* turn, and how native Codex resolves its account.
OpenAI coverage and cost You want the capability matrix, memory embeddings, or how subscription quota and Platform billing are reported.
OpenAI image generation You are generating or editing images through the bundled openai plugin.
OpenAI voice and speech You are configuring text-to-speech, transcription, or realtime voice, including per-route auth order.
Azure OpenAI endpoints You are pointing the bundled openai provider at an Azure OpenAI resource.
OpenAI advanced configuration You are tuning prompt contribution, transport, Fast mode, compaction, strict-agentic mode, or proxy compat.

Where each section moved

Every anchor the single-page version published still resolves here, so an existing link such as /providers/openai#implicit-agent-runtime keeps working. Each entry points at the page that now holds the content.

OpenAI setup

OpenAI models

OpenAI runtimes and Codex auth

OpenAI coverage and cost

OpenAI image generation

OpenAI voice and speech

Azure OpenAI endpoints

OpenAI advanced configuration

Related

For hosted execution, file handling, and connected tools in chat, see the Agents API guide.

Model selection

Choosing providers, model refs, and failover behavior.

Image generation

Shared image tool parameters and provider selection.

Video generation

Shared video tool parameters and provider selection.

OAuth and auth

Auth details and credential reuse rules.