Microsoft partnership with OpenAI has become increasingly strained by the AI startup’s need for more funding and computing power, Microsoft’s recruitment of leaders from OpenAI rival Inflection AI, and questions over the Redmond company’s equity stake in any future version of OpenAI as a for-profit company.

OpenAI has tried to change its deal with Microsoft; Microsoft has tried hedging its bet on OpenAI. The “best bromance in tech” may be unraveling.

The alliance between the technology giant and the company behind OpenAI has been hugely consequential — but a disruption could shake up the A.I. race.