OpenAI

OpenAI brand colours

Extracted from the artwork and ranked by how much of the mark each covers, not from a brand book, so treat them as observed rather than official.

The broadest first-party surface in the category: text, reasoning, realtime audio, image generation, embeddings, moderation and a hosted agent runtime, all under one key. The Responses API is the current front door and carries most of the agentic features. OpenAI's request format is also the category's lingua franca, almost every competitor and router ships a compatibility endpoint that imitates it.