Using Step 3.7 Flash on OpenRouter

Quick Start

1. 1
   Create an account at OpenRouter and generate an API key.
2. 2
   Use the OpenRouter SDK or REST API to call stepfun/step-3.7-flash-20260528 — see the documentation for request format.
3. 3
   You'll be billed $0.20/1M input, $1.15/1M output tokens. See full pricing.

Code Examples

About OpenRouter

OpenRouter provides a unified interface for Large Language Models with better pricing, improved uptime, and no subscription requirements. Route across providers for cost optimization and reliability.

OpenRouter is a multi-provider LLM aggregator offering unified API access to 300+ models from all major labs and emerging providers, with automatic failover for reliability.

Pricing on OpenRouter

Capabilities

About Step 3.7 Flash

Step 3.7 Flash is StepFun's open-weights multimodal Mixture-of-Experts model for agentic coding, tool use, long-context reasoning, image understanding, and video understanding. It combines a 196B-parameter language backbone with a 1.8B-parameter vision encoder, activates about 11B parameters per token, supports a 256K-token context window, and exposes low, medium, and high reasoning levels for speed/depth tradeoffs. StepFun reports leading open-model results on ClawEval-1.1, SimpleVQA with Search, and SWE-bench Pro at launch. Weights are available on Hugging Face under Apache 2.0.