The disruptive device, potentially named the Galaxy X or Galaxy F, was first teased in 2014 but details of the project have remained secret in the years since.
In a break with its usual policy of keeping new products under wraps until they're ready to launch, Samsung plans to share some of the phone's features at the Samsung Developer Conference 2018, taking place in San Francisco from 7-8 November.
Speaking anonymously to Reuters, a Samsung official said the company would seek critical feedback from developers so they can make sure apps are compatible with a folding device.
"Unlike our flagship products, the foldable phone is a completely new concept in terms of design and user experience, which requires a different approach," the official said.
"Before we take it to the market, we want to share with developers what we've done so far and see what they think of it."
Samsung has reportedly been speaking to Netflix and YouTube already in order to figure out ways to optimise content on a folding screen.
Announcing this week's event on its website, Samsung Mobile said the annual developer conference is designed to "showcase the advancements it has made in software and how it wants to go about making life easier for developers to make apps for its devices."
Previous leaks suggested Samsung has already built a 7-inch prototype device, code named 'Winner', that is capable of folding in half like a wallet.
The unveiling of the new Samsung device comes just a week after a US startup unveiled the "world's first commercial foldable smartphone" at an event in China.
The Royole FlexPai handset aims to provide the portability of a smartphone with the screen size of a tablet.
“The Royole FlexPai foldable smartphone provides mobile phone users with a revolutionary, different experience compared to traditional phones,” said Royole CEO Bill Liu.
“It perfectly solves the contradiction between the high-definition large-screen experience and portability, which introduces a whole new dimension to the human-machine interface. The phone’s inherent design will forever change the consumer electronics industry, as well as the way people interact with and perceive their world."
Other smartphone manufacturers rumoured to be working on a foldable device include Huawei and LG, though like Samsung, their release date is not expected until at least 2019.
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