OpenAI Details Architecture of ChatGPT Ads Stack

OpenAI detailed the engineering behind its advertising system for ChatGPT, explaining how it handles evolving user intent across multiple turns of a conversation. The new ads delivery system relies on a custom, post-trained frontier large language model that acts as an orchestrator to make tool calls for retrieval, ranking, relevance evaluation, and auctions.

The architecture separates ad selection from ChatGPT's organic answer generation. Operating in a separate service, the ads system maintains a stateful session that tracks conversation history without influencing core responses. This separation ensures that if the ad serving infrastructure slows down or becomes unavailable, ChatGPT's primary response generation continues unaffected.

According to OpenAI, ChatGPT Ads reached $1 billion in annualized revenue run rate less than 200 days after launch, and more than 100,000 advertisers have run ads on ChatGPT since launch.

Read the original announcement