OpenAI's enterprise platform adds Chinese open-source models Kimi K3 and GLM 5.3 for the first time

US AI infrastructure company Baseten announced a partnership with OpenAI, becoming one of the first open-source model inference providers on OpenAI's B2B marketplace. Enterprise users can now access open-source models like Kimi K3 and GLM 5.3 through Codex, marking the first time Chinese open-source models have entered OpenAI's enterprise procurement system.

Kimi K3 is developed by Moonshot AI. The company claims it is the first open-source model with 2.8 trillion parameters, natively supporting vision and featuring a 1 million token context window, making it suitable for long coding sessions and multi-document analysis.

OpenAI enterprise users can now call these models via Codex or the Responses API, getting more AI capabilities for the same budget. Baseten promises all models run on US servers with zero data retention for all prompts.