Amazon’s Alexa and your Pebble watch will call you an Uber. If you’ve had too much too drink, so will the Breathometer device and app. StubHub and OpenTable will prompt you to call an Uber before a concert or restaurant reservation. Facebook Messenger, Slack, the Hipchat messaging service and the United Airlines app can all summon Uber rides.

Since 2014, Uber has offered technology called an application programming interface, or API, to let other software developers tap into its ride-hailing system.

Adding a ride-request button — the first feature Uber offered — was just the beginning. This year Uber released new interfaces to let outside companies tap into its UberRush delivery service and provide entertainment, news or local guides during a ride.

The three digital building blocks let developers “move their users from point A to point B; move their stuff from A to B; or create experiences for users while they’re moving from A to B,” said Chris Saad, head of product for the Uber developer platform. His 29-person team works with thousands of companies using Uber’s API, ranging from multinational corporations to city transit planners to dorm-room startups.

“Whether they’re Facebook, Google or indie developers in their parents’ basement, we want to make sure they have an opportunity to get their hands dirty and build something meaningful,” he said. Uber hosts hackathons, visits startups and has frequent meetings with companies to support the development of Uber-related products.

An entrepreneur from Australia, Saad had founded his own startups but had never worked at a big company before joining Uber last year. The attraction, he said, was affecting transportation on a global scale.

“I’m interested in creating a canvas on which other people can creatively solve problems,” he said.

Amazon’s success with its Web Services division, which provides computing power and storage for other software companies, inspires his work at Uber. “Web 1.0 companies had to invest millions of dollars in hardware before they could build their ideas,” he said. “Amazon Web Services changed the economics by enabling an explosion of innovation.”

Similarly, establishing an on-demand business now is much easier for companies that can simply use Uber to handle the logistics, rather than recruiting their own drivers and creating software to dispatch them. “Creating an ‘Uber for X’ doesn’t have to be capital intensive; it’s just pay-as-you-go,” Saad said.

Lyft, Uber’s archrival, also has an API, though it didn’t open it up until March. By letting other companies tap into their infrastructure, Uber and Lyft are helping spur innovation, said Michael Ting, an expert on APIs and a senior vice president at payment service Hyperwallet, which does not have a relationship with either company.

“They’ve created complex logistical flows to enable thousands of riders and drivers to connect and know where they are at any given time,” he said. “The UberRush API isn’t just giving other companies a technology, it’s giving them a fleet of drivers who will actually get dispatched to do deliveries. Putting together a fleet would be a huge hurdle for any company. Uber already did the heavy lifting, and (third parties) can just piggyback on that and focus on their own product.”

That’s the case for San Francisco’s Pythagoras, which makes artisanal pizzas. While it has its own small delivery staff, it found that it couldn’t handle unexpected increases in volume — after a rave review, for instance. So it integrated UberRush deliveries into its app.

“We use UberRush to deal with elasticity of demand,” said CEO Evan Kuo. “It didn’t make sense for us to hire more drivers and pay them to essentially sit around. UberRush has changed the game for us.”

Pythagoras still handles about three-quarters of deliveries itself, but now can easily expand to meet a surge in demand — on big game days, for instance. It pays Uber $6 for the first mile and $3 for each additional mile. “It ends up working out to be about the same rate as our own drivers,” Kuo said.

Of course, companies don’t invite other firms to piggyback their technology as an act of charity: It brings benefits to the company that opens itself up. One big case in point: Facebook, which was far smaller than rivals like Myspace when it created a developer platform in 2007. Microsoft soon followed with a $240 million investment in the fledgling social network.

“Opening its platform to developers was a pivotal point for Facebook,” Ting said. “They had just focused on creating connections between people. The developer constituency opened a lot of people’s eyes to the ways Facebook could be monetized.”

For ride services, that opportunity comes in increasing their ubiquity and usefulness. Uber declined to say how many new riders its outside developers have brought in, but it pays them $5 for each new U.S. passenger. It said more than 10,000 apps have integrated its Ride Request feature, and hundreds have added UberRush since it was made available in June.

Uber is famous — or infamous — for sometimes-pugnacious relationships. And many companies — Apple is a case in point — have drawn wrath from third-party developers by releasing products that crowd out independent offerings. Compared to its white-knuckled business dealings with taxi competitors, Uber’s developer relationships seem positively placid.

“We try hard to have a high degree of empathy for developers and their needs,” Saad said. “We want them to continue to iterate around and on top of what we’re doing.” There have been times, Saad said, when a developer built something and Uber coincidentally had something similar in the works. For instance, Teleport, an app that lets people easily order Uber rides for their friends, resembles UberCentral, a feature the company added last month for businesses to order rides for customers.

Uber doesn’t shut out companies that have similar ideas on the premise that there’s room for everybody, Saad said. “It’s not our job to pick winners and losers.”

Uber’s developer team has been friendly and supportive, said Jianming Zhou, co-founder and CEO of SherpaShare, which this week is releasing an app called Jack’s Compass to help drivers navigate to places where they’re more likely to get pinged. SherpaShare used the Uber API plus its own information on some 100,000-plus drivers who use its existing mileage tracking tool, to generate the data for the app.

Saad waxes enthusiastically about some products. There are small ones like Rally, which lets a group of friends arrange to meet for dinner. “You can get food and a car on demand; why not get friends on demand?” Saad said. Bluesmart, a “smart suitcase,” uses Uber drivers to retrieve misplaced bags from the airport and deliver them to their owners. Up Sonder uses UberRush to deliver rental drones on demand.

Then there are huge ones: MedStar Health System, a nonprofit, provides Uber rides to and from doctor appointments and Practo, an Indian startup with a mobile health care app, has a button for patients to request Uber rides to and from doctor appointments.

“There’s been a consistent drumbeat of innovation and new bits for developers to play with,” Saad said. “We want to accelerate that pace.”