StepFun Launches STEPX Neo Smartphone Built Around Amoo AI Agent
Chinese artificial intelligence startup StepFun has officially introduced the STEPX Neo, a smartphone designed with an artificial intelligence agent integrated directly into the operating system rather than functioning as a standalone application. Pre-orders for the handset opened at 3,999 yuan, equivalent to roughly $560, ahead of an initial sales event scheduled for October 16. The company, which is backed by Tencent, began taking customer reservations across Chinese e-commerce channels including JD.com, Tmall, and Douyin. During the launch presentation, company representatives told the audience that artificial intelligence is no longer merely an add-on to a smartphone but the primary product itself.
StepFun raised more than 5 billion yuan ($717 million) in a new funding round.
Operating System Architecture and Core Platform Design
StepFun stated that the device operates on Step AOS 1.0, an operating system engineered specifically for agent workflows with base-layer security controls, task scheduling, and long-term memory. Company executives describe the underlying software stack as an integrated combination of Android, Linux, and real-time operating system components. Step AOS organizes standard handset functions such as files, settings, messaging, and applications into modular units using the Model Context Protocol, allowing programs to connect directly to external software. Users navigate the interface through dual entry points, accessing either a traditional application grid or a dedicated operating space reserved for the assistant.
Amoo Agent Capabilities and Dual Memory System
The integrated agent, named Amoo, maintains two distinct memory banks, storing user personal preferences and habits in one partition while recording operational task procedures in another. Routine operations like configuring an alarm execute locally through a compact on-device model with offline support, whereas multi-application requests are processed by a larger cloud-based model. A secondary MiniLED display positioned on the rear casing provides real-time visual feedback regarding the actions Amoo is currently performing. StepFun previously showcased the agent, operating system, and the STEPX brand in Shanghai on July 13, noting that legacy mobile software was never engineered for autonomous execution.
Ecosystem Integration and Underlying Language Models
Nearly 100 corporate partners and digital platforms, including Alipay, Tencent, Ctrip, Didi, and Meituan, have integrated services with Amoo while retaining transactions, travel bookings, and content production on their native systems. This cooperative architectural framework provides an alternative to the simulated clicks and screen-reading techniques employed by ByteDance's Doubao agent, which faced access blocks from major Chinese apps in December. StepFun was established in 2023 by former Microsoft vice president Jiang Daxin and develops proprietary large language models to power its platforms. The startup introduced its flagship Step 5 Preview model in September, featuring 600 billion total parameters with 27 billion actively engaged during inference. Step 5 Preview accommodates context windows of up to 1 million tokens, while the company previously released a smaller model, Step 3.5 Flash, under an open-source Apache 2.0 license.
Pricing Terms and Unresolved Subscription Costs
The retail price of 3,999 yuan includes a one-year subscription to the STEPX Token Plan, granting users an allocation of 100 billion tokens per month. StepFun has not disclosed how much subscribers will be charged for artificial intelligence service access following the conclusion of the initial twelve months.