A little over four days after being ousted as one of the most highly visible CEOs in the Bay Area tech scene, Sam Altman has been reinstated as the top exec at OpenAI. And the board that ousted him has mostly resigned.

Echoing a statement that had been shared on social media by many OpenAI employees over the weekend, including interim CEO and former board member CEO Mira Murati, the company tweeted Tuesday night "OpenAI is nothing without its people," alongside a retweet of a selfie taken by co-founder Greg Brockman.

"We have reached an agreement in principle for Sam Altman to return to OpenAI as CEO with a new initial board of Bret Taylor (Chair), Larry Summers, and Adam D'Angelo," the company tweeted.

Microsoft CEO Satya Nadella, who had pledged to hire Altman and Brockman and whoever else at OpenAI wanted to leave over the weekend, had begun hedging in interviews on Monday about the situation. And on Tuesday night, Nadella tweeted, "We are encouraged by the changes to the OpenAI board. We believe this is a first essential step on a path to more stable, well-informed, and effective governance."

And Altman himself tweeted, "i love openai, and everything i’ve done over the past few days has been in service of keeping this team and its mission together. when i decided to join [Microsoft] on [Sunday] evening, it was clear that was the best path for me and the team. with the new board and w satya’s support, i’m looking forward to returning to openai, and building on our strong partnership with [Microsoft]."

It appears from Brockman's tweet that there were a lot of OpenAI employees in the office at midnight last night...

While OpenAI is a for-profit company, it has a unique governance structure in which it was wholly run by a non-profit board of directors. That original board included D'Angelo, who is the CEO of Quora, along with company co-founder and chief scientist Ilya Sutskever, Murati, Brockman, tech entrepreneur Tasha McCauley, and Helen Toner of the Georgetown Center for Security and Emerging Technology.

Early Monday, Sutskever, who was said to be leading the charge to oust Altman, tweeted, "I deeply regret my participation in the board's actions. I never intended to harm OpenAI. I love everything we've built together and I will do everything I can to reunite the company." It appears Sutskever remains at the company, if not on the board, and he retweeted posts by Brockman and Altman Wednesday morning.

This also means that former Twitch CEO Emmett Shear, who was named CEO of OpenAI Sunday night, is back out of a job. Shear resigned from Twitch in order to be with his newborn son nine months ago.

The announcement closes out this brief but chaotic chapter for OpenAI, which in the last year has been one of the most-watched companies in the nation, as well as in the Bay Area. The company only recently inked a deal to take over part of Uber's Mission Bay campus, and they have been on a hiring spree as well.

The company has 778 employees, up from just a few hundred in 2021. As of last month, the company was valued at $90 billion.

Previously: Sam Altman Appears to Be Engineering His Reinstatement at OpenAI