StepFun launches a 3,999-yuan phone with an AI agent built into its operating system

StepFun has launched an early-access smartphone in China that puts an AI agent inside the software running the phone, rather than offering it as another app. The STEPX Neo costs 3,999 yuan and opened for preorders on October 13, 2026, giving the startup a consumer device for its approach to completing tasks across services.

An agent entrance alongside the app grid

The phone runs Step AOS 1.0. StepFun says it built the operating system from scratch around Amoo, its agent, with long-term memory, task scheduling and security controls in the base software. The company describes the system as a combination of Android, Linux and real-time operating-system components.

The distinction is how the agent reaches the phone’s functions. Step AOS divides messaging, apps, files and settings into smaller functions that Amoo can call directly. It connects them through Model Context Protocol, or MCP, a shared standard for linking AI programs to other software.

StepFun’s proposed interaction replaces a sequence of manual steps with a goal. For a ride, for example, the user tells the phone where to go rather than opening an app, entering an address and choosing a car. Amoo is designed to handle the remaining steps across supported services.

That does not mean removing apps. Users can choose between a familiar app grid and a separate agent space. Amoo also keeps two kinds of memory, separating knowledge about the person from knowledge about doing the work:

• Personal memory stores the user’s facts, habits and preferences.
• Task memory stores what the agent has learned about carrying out tasks.

Local awareness, cloud-based heavy lifting

Processing is split between the handset and remote computing. A small model on the phone handles simple commands such as setting alarms, with some commands available offline. More demanding requests involving several apps go to a larger cloud model. A second MiniLED screen on the back displays what Amoo is doing.

A supplier announcement adds detail about how the phone gathers context. On October 15, Syntiant said the STEPX Neo incorporates its NDP120 neural processor and six SiSonic microphones. These components support selected audio and voice-sensing tasks that run continuously on the device, including its Intelligent Hearing Enhancement System.

Syntiant says this sensing layer can capture useful context before a user issues a prompt, while reducing the need to wake the main processor. Its efficiency and privacy benefits are supplier claims. The described role is continuous local sensing, separate from the larger cloud model used for harder requests.

Partner services remain part of the transaction

StepFun says nearly 100 companies and products have signed on to Amoo, including Alipay, Tencent, Ctrip, Didi and Meituan. Payments, travel bookings and content creation still take place through the participating platforms. The agent changes how users reach those services; it does not replace the platforms completing the transaction.

Preorders opened through JD.com, Tmall and Douyin, with the first sales event on October 16. The purchase price includes 12 months of the STEPX Token Plan, offering 100 billion tokens per month. Tokens are the units AI services use to measure how much text they process.

That allowance makes AI access part of the initial phone purchase, but not a settled lifetime cost. StepFun has not disclosed what the service will cost after the first year. Buyers therefore have a stated hardware price and initial usage allowance, but no announced renewal price.