PFU

Chinese AI startup StepFun's new model, Step 5 Preview, is now accessible through OpenRouter. The model is a mixture-of-experts architecture with a 1 million-token context window, placing it among the largest-context models available through the aggregator. Tech observers are noting that a leading Chinese lab continues shipping frontier-class models internationally, and developers are likely to test its long-context handling against rivals from Anthropic, Google and OpenAI.