Ina FriedAdd Axios as your preferred source tosee more of our stories on Google.Illustration: Annelise Capossela/AxiosMicrosoft used its Build developer conference on Tuesday to debut the company's first internally developed reasoning model, along with a personal AI agent dubbed Scout that is built on top of OpenClaw.Why it matters: Microsoft is seeking to show it is a serious player in AI above and beyond its relationship with OpenAI.Driving the news: The new reasoning model, dubbed MAI-Thinking-1, is a mid-sized model (35 billion active parameters) and designed to compete more on cost than by rivaling the most powerful frontier models. Microsoft also noted that it was not distilled from any other models and is trained only on commercially licensed data, rather than simply the kinds of "publicly available" data typically used to train large language models.As for Scout, Microsoft didn't announce the full details of the agent, but said it will work on its own within tools such as Outlook and Teams and can help with tasks such as preparing for meetings.In addition, the company announced a coding model and updates to its voice and image models.That's all on top of the announcement earlier this week that a new class of Windows PCs powered by Nvidia chips is coming later this year.Microsoft also announced Project Solara, an Android-based operating system designed to run AI agents on a range of small devices such as earbuds and speakers.The big picture: It's the heart of developer conference season, as each of the big tech players aims to make the case why their platform is the one worth building on.Google used its I/O event last month to announce a laundry list of new AI tools, including its Spark agent, new Gemini models, a revamped search bar and conversational search in YouTube.Apple, meanwhile, is expected next week to debut a revamped Siri powered (at least in part) by custom versions of Google's Gemini.