StepFun launches STEPX Neo smartphone with built-in AI agent Amoo

Market Intel · Just now · Not financial advice

StepFun, the Chinese AI startup backed by Tencent, has thrown its hat into the smartphone ring with the STEPX Neo, a device that places an AI agent at the center of the experience rather than hiding it inside an app. Pre-orders opened on Oct. 13 at 3,999 yuan, roughly $560, through JD.com, Tmall and Douyin.

AI Agent Takes the Wheel

The STEPX Neo runs Step AOS 1.0, an operating system purpose-built for autonomous task execution. Instead of opening multiple apps to complete a task, users simply tell the phone their destination and the built-in agent called Amoo handles the rest. StepFun describes the system as a mix of Android, Linux and real-time operating system components, with long-term memory, task scheduling and security controls embedded in the base layer.

Partner Ecosystem

Nearly 100 companies have signed on to support Amoo, including Alipay, Tencent, Ctrip and Didi. These partners integrate payments, travel bookings and content creation directly into the phone's agent layer, creating an alternative to the traditional app-click approach. The price of the STEPX Neo even includes 12 months of AI access with 100 billion tokens per month.

The LLM Powering the Phone

StepFun first showed the agent, the operating system and the STEPX brand in Shanghai back in July, pricing the device only later for launch. The company's flagship LLM, Step 5 Preview, arrived in September with 600 billion parameters, of which 27 billion are active at any given time. Step 5 Preview can process up to 1 million tokens simultaneously, while the smaller Step 3.5 Flash model is open-source under an Apache 2.0 license.

The STEPX Neo enters a market where AI and smartphones are increasingly intertwined, but StepFun's approach — making the agent the product rather than an assistant — could shift how users interact with their devices. By baking task execution into the OS itself, the phone eliminates the friction of app-switching and signals where the industry may be heading as AI becomes less of a feature and more of a foundation.