StepFun announced on October 12 that its Step 5 Preview model is now available in WorkBuddy, Tencent's AI-native office agent. From October 12 to October 25, Step 5 Preview can be used for free on WorkBuddy, an arrangement StepFun described as exclusive, according to IT Home.
The announcement covers access and timing only. StepFun did not say what happens to pricing in WorkBuddy after the two-week window closes, or whether the model will become a permanent option in the product.
For WorkBuddy users, the change adds another model choice inside an agent that already handles documents, spreadsheets, scheduling and other office tasks on desktop and mobile. For StepFun, it places its newest flagship directly in front of a large base of office users rather than only developers calling its API.
Step 5 Preview itself is not new. StepFun launched it on September 20 as a flagship aimed at AI coding, software engineering, professional knowledge work and finance, with a focus on agentic tasks in real-world settings. The model uses a sparse mixture-of-experts architecture with 600 billion total parameters and 27 billion active, supports a context window of 1 million tokens, and natively accepts text and visual input. StepFun has said it will release the full weights as open source on October 15, three days into the WorkBuddy promotion.
The timing means WorkBuddy users can try the hosted model during the same period in which developers will be able to download it and run it themselves. Pandaily covered the model's launch and architecture in earlier reports.
WorkBuddy already lets users pick among models from several outside labs. Integrations with outside labs give the agent a broader menu for different tasks, while model makers gain distribution inside one of China's most widely used AI office tools.
SEE ALSO: StepFun Launches Step 5 Preview: 600B Sparse MoE, 1M Context, Weights Open Oct 15 · StepFun Step 5 Preview: ~600B MoE Long-Horizon Agent; Open Weights Due Oct 15