Microsoft added SpaceXAI’s Grok models to its Foundry service last year, and now it’s expanding the access to Copilot itself. Grok models can now be used in Word, Excel and PowerPoint from the model picker interface for Microsoft Frontier users. Microsoft says it’s starting with a preview release to “gather feedback.” This means Office Copilot users can now pick between OpenAI’s GPT models, Anthropic’s Claude models, and SpaceXAI’s Grok models.