That moment when you realize you're exchanging emails with a robot

Next time you schedule a meeting and an assistant named Amy or Andrew Ingram sets up the logistics, here's a pro tip: You may be chatting with a robot. And if it's one of x.ai's bots, you might never know the difference.

That was my experience when I exchanged emails with "Andrew" to set up an interview with x.ai's CEO. After I emailed x.ai's press contact, she referred me to Andrew to hammer out the details. Andrew proposed a time, thanked me when I accepted and sent out a calendar invitation. Had I not been clued in ahead of time, I never would have realized Andrew wasn't human.

Therein lies x.ai's value proposition.

Founded in 2014, x.ai is focused squarely on perfecting one thing: the scheduling of meetings.

That's a process that can involve a lot of pain today, thanks to all the back-and-forths that inevitably ensue. But x.ai thinks its AI personal assistant can make the pain go away. You simply cc: one of them, and "she" or "he" will take over the task.

It's a very different kind of AI from, say, Cortana or Siri, in that it's focused narrowly on a specific task.

Underlying the technology are two key capabilities. Text understanding is one, in that the robot needs to understand not just key words but the full text and context of emails.

"There can be no ambiguity," said CEO Dennis Mortensen. "If you say, 'let's do one,' what does that mean? Is it one o'clock? Is that pm? Is it EST? Amy has to understand the intent along with the date, time, location, people involved and constraints."

At least as challenging is the second capability - generating text that sounds like it came from a human.

"Andrew needs to have this idea of what dialogue is about to happen here," Mortensen said. "He needs to make sure the conversation doesn't go around in circles."

That means avoiding boatloads of potential ambiguity along the way.

"You can't be in doubt about what's going on, and if someone needs to postpone or cancel, Andrew needs to understand that that is an unfortunate thing," Mortensen said. "He needs to have empathy, but do what needs to be done to make it happen anyway."

A still-evolving combination of deep learning, machine learning, neural networks and other artificial-intelligence techniques are what makes x.ai's offering possible.

"We need accuracy at a level so high that we try to find the best technique for each distinct problem," Mortensen said.

X.ai is still in beta, but the number of meetings scheduled through its robots is growing. In February, that count was up by 27 percent over January, and March saw another 28 percent uptick, the company says.

On Thursday, x.ai took in a fresh $23 million in Series B funding, bringing its total to almost $35 million. It plans to use the new funds to extend its data-science team and support the rollout of its pro and business editions later this year.

Mortensen doesn't rule out the possibility of an expanded reach down the road, but for now, he plans to continue x.ai's focus on meetings.

"More than 10 billion meetings are scheduled in the U.S. alone every year," he said. "That's what we're hunting here. We don't want to be half-assed at five things; we want to be world-class at one thing."

And for those worried about the ascendance of a new breed of robotic overlords, Mortensen isn't concerned.

"I set up 1,019 meetings in 2012 all by myself," he said. "I cried myself to sleep at night."