# OpenRouter adds StepFun Step 5 Preview model

> StepFun's new Step 5 Preview, a 27 billion‑parameter expert model, is now available on OpenRouter for agentic tasks.

Oossa · 2026-10-08 · https://oossa.com/en/openrouter-adds-stepfun-step-5-preview-model

OpenRouter announced that the StepFun Step 5 Preview model is now live on its platform. The model uses a sparse Mixture‑of‑Experts design with 27 billion active parameters out of a total of 600 billion. It is marketed for agentic work such as software engineering and other professional tasks. The context window supports up to 1 million tokens.

## The facts

- Step 5 Preview launched on Oct 8, 2026
- 27 B active parameters, 600 B total, 1 M token context

## Why it matters

Developers can now run larger, more specialized models for coding assistance without needing their own high‑end hardware.

## Sources & references

1. [New on OpenRouter: StepFun: Step 5 Preview](https://openrouter.ai/stepfun/step-5-preview) – OpenRouter API, 2026-10-08

Last updated: 2026-10-08