Interesting essay about Amazon’s smart lock:

When you add Amazon Key to your door, something more sneaky also happens: Amazon takes over.

You can leave your keys at home and unlock your door with the Amazon Key app — but it’s really built for Amazon deliveries. To share online access with family and friends, I had to give them a special code to SMS (yes, text) to unlock the door. (Amazon offers other smartlocks that have physical keypads).

The Key-compatible locks are made by Yale and Kwikset, yet don’t work with those brands’ own apps. They also can’t connect with a home-security system or smart-home gadgets that work with Apple and Google software.

And, of course, the lock can’t be accessed by businesses other than Amazon. No Walmart, no UPS, no local dog-walking company.

Keeping tight control over Key might help Amazon guarantee security or a better experience. “Our focus with smart home is on making things simpler for customers ­– things like providing easy control of connected devices with your voice using Alexa, simplifying tasks like reordering household goods and receiving packages,” the Amazon spokeswoman said.

But Amazon is barely hiding its goal: It wants to be the operating system for your home. Amazon says Key will eventually work with dog walkers, maids and other service workers who bill through its marketplace. An Amazon home security service and grocery delivery from Whole Foods can’t be far off.