StepFun

What is StepFun?

Step AI by Jieyue Star (Jieyue Xingchen) is a powerful suite of large language and multimodal models designed to help developers, businesses, and creators build real-world AI applications—from coding assistants to intelligent agents. Launched in April 2023 with the mission “Scale-up possibilities for everyone,” Step AI combines cutting-edge self-developed models with easy-to-use APIs and tools.

Built on proprietary research, the Step series includes models like Step 3.7 Flash, Step 3.5 Flash, and Step 1, each optimized for speed, reasoning, or multimodal understanding. Whether you're parsing PDFs, generating code, or building agent workflows, Step AI delivers stable, high-performance inference with seamless integration—making advanced AI accessible without the complexity.

What are the features of StepFun?

• Step 3.7 Flash

  A high-efficiency multimodal model built for real Agent workflows—understands images, UI screenshots, charts, and tables natively without extra middleware.
• Step 3.5 Flash

  An ultra-fast language model engineered for Agents, offering rapid response times while maintaining strong instruction-following capabilities.
• Step 2

  A trillion-parameter base model with deep reasoning power and precise multi-turn instruction handling, rivaling leading industry models.
• Step 1

  Proven in production with millions of users, supports long-context, low-bit inference on single GPUs and excels at multi-round conversations.
• Open Weights & Customization

  Flagship models come with open weights, allowing deployment, fine-tuning, and full customization for enterprise needs.
• Native Multimodal Understanding

  Directly interprets PDFs, spreadsheets, diagrams, and app screenshots—no visual MCP layer needed, reducing latency and cost.
• Agent-Ready Tool Calling

  Fully compatible with mainstream Agent frameworks, enabling stable execution in office automation, coding, and complex task workflows.
• Step API

  Offers stable, high-performance, and easy-to-integrate endpoints for language, speech, and multimodal/GUI models.

What are the use cases of StepFun?

• Automating document analysis by extracting data from PDF reports, financial tables, or technical diagrams in one pass.
• Building AI coding assistants that understand context, generate robust code, and debug across multiple programming languages.
• Creating intelligent office agents that schedule meetings, draft emails, and summarize documents based on user instructions.
• Developing multimodal customer support bots that interpret user-uploaded screenshots or forms and respond accurately.
• Powering custom enterprise workflows like invoice processing, compliance checks, or internal knowledge retrieval.
• Deploying on-device or private-cloud AI apps using open-weight models for data-sensitive environments.
• Rapid prototyping of next-gen AI products via the Step AI Open Platform with minimal setup time.

How to use StepFun?

• Visit the Step AI official website (formerly StudioEN) to access the web chat interface or developer portal.
• Sign up for an account

  to get API keys and start testing models like Step 3.5 Flash or Step 3.7 Flash instantly.
• Integrate Step API into your app using clear documentation—supports RESTful calls with JSON payloads.
• Download the Step AI desktop app for macOS (11.3+) or Windows (10+) for a personal AI work companion.
• Use the mobile app (iOS/Android) for on-the-go access to AI assistance—scan the QR code on the website to install.
• Explore the Document Center and Experience Center to find code samples, tutorials, and best practices for Agent development.