StepFun's STEPX Neo Is the First Phone Built Around an AI Agent

A Chinese AI startup has done what the industry's giants have only talked about: it shipped a phone where the AI agent is the product, not a feature. StepFun launched the STEPX Neo on October 13, a 3,999-yuan handset — roughly $560 — whose operating system was built from scratch around an on-device agent called Amoo, according to Decrypt's October 17 report on the launch.

The STEPX Neo is billed as the first commercially available smartphone with an agent-native operating system, and its arrival turns a long-running demo-circuit promise into something you can actually order. Pre-orders opened that evening on JD.com, Tmall and Douyin, with the first sales event held on October 16. StepFun framed the launch around a single thesis: in the agent era, artificial intelligence is no longer an add-on to the smartphone — it is the product itself, according to Decrypt's account of the launch presentation.

An operating system built for the agent, not the app

Siri and Gemini are assistants that live inside iOS and Android. StepFun says its Step AOS 1.0 was instead designed from the ground up for autonomous task execution, with long-term memory, task scheduling and security controls sitting in the base layer. The company describes the system as a blend of Android, Linux and real-time operating system components.

Rather than bolting an agent onto a conventional app grid, Step AOS breaks phone functions such as messaging, apps, files and settings into small blocks the agent can call directly, using the Model Context Protocol, the shared standard that lets AI programs plug into other software. Users get two entrances to the device: the familiar app grid, and a separate space where the agent does the work.

The agent, called Amoo, keeps one memory for the user's facts, habits and preferences and a second memory for what it has learned about carrying out tasks. Simple commands such as setting an alarm run on a small model inside the phone, some of them offline, while harder requests that span several apps are handed to a larger model in the cloud. A second MiniLED screen on the back of the STEPX Neo shows what Amoo is doing at any moment — a window into the agent's working process that conventional phones simply do not have.

StepFun first showed the agent, the operating system and the STEPX brand at an event in Shanghai on July 13, without a price or a sales date. The company said at the time that conventional smartphone software was never built for autonomous task execution, and the STEPX Neo is its answer.

Nearly 100 partners and a token-bundled price

The STEPX Neo is only as useful as the services its agent can reach, and this is where StepFun took a different path from its predecessors. Nearly 100 companies and products — including Alipay, Tencent, Ctrip, Didi and Meituan — have signed on to Amoo, with payments, travel bookings and content creation still completed by their own platforms. That official-integration approach is StepFun's alternative to the screen-reading and simulated-click techniques that drew blocks from major Chinese apps when ByteDance's Doubao phone agent tried them in December, according to Decrypt.

The pricing model is as unusual as the hardware. The 3,999-yuan price includes twelve months of the STEPX Token Plan, which provides 100 billion tokens a month — an allowance so large that most users are unlikely to come near it. StepFun has not disclosed what AI access will cost after the first year, which leaves the long-term economics of the device an open question, according to The Currency Analytics.

Behind the device sits a serious model effort. StepFun was founded in 2023 by Jiang Daxin, a former Microsoft vice president, and builds its own large language models. Its flagship, Step 5 Preview, arrived in September with 600 billion parameters, of which 27 billion are active at a time, and can take in up to one million tokens at once. The smaller Step 3.5 Flash, released earlier this year, is open-source under an Apache 2.0 license, according to The Currency Analytics.

The race to define the agent-native phone

The STEPX Neo lands in a race that is still wide open. OpenAI and Jony Ive continue building anticipation around their first AI hardware device, but rivals are already putting agent-native hardware on shelves, as industry coverage noted months before the STEPX Neo went on sale. StepFun's bet is that deep operating-system integration — not a chatbot layer on top of Android — is what separates a real AI phone from a marketing exercise, according to AI Parabellum's analysis of the launch.

For the STEPX Neo, big questions remain around long-term costs after the token plan expires, security and data handling with an agent sitting at the OS level, and whether the partner network of nearly 100 companies gives Amoo enough everyday utility. The phone is also only available in China for now, which limits how fast the agent-native phone category can go global.

Still, the STEPX Neo makes the direction of travel concrete. The same week it went on sale, the industry was debating whether websites should let AI agents in at all — a tension between open and gated agent access that is now playing out on both the web and the handset. Whether agents reach services through official partnerships, as Amoo does, or through the crawling and screen-scraping that some platforms are moving to block, will shape what agent-first devices like the STEPX Neo can actually do. For now, StepFun has the first commercially available answer in buyers' hands.

For more on the agent-access debate, see Websites Are Blocking AI Agents Across the Web and ServiceNow AI Passport Gives AI Agents Signed Credentials.

Sources: Decrypt, AI Parabellum, The Currency Analytics.