Step 5 Preview, StepFun's flagship model, is now available on AI Gateway. It's built for agentic coding, professional knowledge work, and financial analysis, from building apps and debugging code to research and analytical reports.
Step 5 Preview supports text and image input with a 1M-token context window, allowing you to work with large codebases, a stack of documents, or screenshots and charts in a single request.
Use `stepfun/step-5-preview` as the model name:
For other coding agents such as Claude Code, Codex, Cursor, and more, install the latest Vercel CLI and run setup:
Then select `stepfun/step-5-preview` in the agent. See the [coding agents guide](https://vercel.com/docs/ai-gateway/coding-agents) for details.
Try Step 5 Preview in the [model playground](https://vercel.com/ai-gateway/models/step-5-preview).
AI Gateway provides a unified API for calling models, tracking usage and cost, and configuring retries, failover, and performance optimizations for higher-than-provider uptime. It includes built-in custom reporting, Zero Data Retention support, budgets for API keys, routing rules, and more.
AI Gateway reflects provider pricing with no markup and does not charge a platform fee on inference, including on Bring Your Own Key (BYOK) requests.
You can view all language models available on AI Gateway.