"primary interface" is correct and usable in written English.
You can use "primary interface" when referring to the main point of contact through which two or more systems interact. For example: "The primary interface between the computer processor and the user is the keyboard and monitor."
The primary interface element of Now is what Google calls "cards," which are modelled after real cards.
In the future, the cellphone and similar wireless devices, not the personal computer, will be the primary interface to the cloud of information services that we now call the Internet.
But despite the talk of unity, Mr. Bush has clearly placed social conservatives at the center of his domestic agencies, while placing Republicans from the moderate wing of the party, like Secretary of State-designate Colin L. Powell, Ms. Rice and Treasury Secretary-designate H. O'NeillNeinl in command of the corners of government that are America's primary interface with the world.
The primary interface in a MyFord Touch-equipped vehicle — I tested a 2012 Focus for this article — is a touch screen high in the center of the instrument panel.
Today, Headspace's primary interface is audio.
The primary interface is a big circle in the center.
It turns out at that Tacoma is riddled with 3D cameras that have recorded every moment of the crew's life aboard the ship – on top of that, all the crew wore augmented reality headsets as their primary interfaces with the station itself – all these were also recording point-of-view footage.
An interface architecture is a repository with some primary interfaces identified; the import dependencies between the interfaces of a repository are used to determine its structure.
The mucosal layer of the GI tract, airway, skin surface and reproductive tract surface are the primary interfaces of host-microbe interactions.
Twitter Users are currently given two primary interfaces through which they can interact with the growingly popular service: by the Twitter website itself or through TXT messaging via mobile phone.
"Our primary interfaces to our music look like spreadsheet apps," says the site description.
