StepFun launches STEPX Neo AI agent phone at 3,999 yuan early access

Chinese AI model developer StepFun has put its first AI agent smartphone, the STEPX Neo, into early access for 3,999 yuan (about $597), Caixin Global reports. The pitch is not another Android skin: StepFun is shipping its own operating system so agents can talk to services without depending on traditional app-store gatekeepers.

From model lab to handset

StepFun showed the phone at the World AI Conference 2026 in Shanghai in July, alongside other AI-first devices such as the Nubia NaviX Ultra and Honor Robot Phone. Ecosystem partners named by Caixin include Alipay, Meituan and Tencent’s WorkBuddy — the kind of closed service silos that agent phones need to open if “do it for me” workflows are going to work.

Before building its own device, StepFun had already worked with Oppo, Honor, automaker Geely and assisted-driving firm Afari on mobile assistants and cabin systems. In May 2026 the company raised $2.5 billion in a pre-IPO round, giving it the cash to try a hardware move most pure software labs skip.

Who wins: software crossover or hardware upgrades?

Qualcomm China chairman Meng Pu told Caixin it is still too early to say whether software-led crossovers or traditional hardware upgrades will win in AI phones, and that the category will need sustained technical investment either way. That caution fits a crowded field where Oppo, Vivo and others are also pushing AI-adapted systems.

On third-party model rankings, StepFun’s Step-5-Preview scored 44 on the Artificial Analysis board — tied with Kimi K3, but behind Xiaomi MiMo-V2.6-Pro, Alibaba Qwen3.8-Max and Z.AI GLM-5.3. The phone launch is therefore as much a bet on OS and agent UX as on topping every benchmark.

Caixin’s piece does not list independent battery, camera or chipset lab results for the early-access STEPX Neo, so treat the debut as a software-and-ecosystem story until those specs land. For buyers outside China, pricing, carrier support and language availability are also unstated in the report.