Step 3.7 Flash

Facts

Released

2026-05-23 the day the repository was first published on Hugging Face Hugging Face, read 2026-09-24

Licence

apache-2.0 the licence the model card declares Hugging Face, read 2026-09-24

Open weights

Yes the weights are published in this Hugging Face repository Hugging Face, read 2026-09-24

Parameters

201.4 billion counted from the safetensors weight files Hugging Face, read 2026-09-24

Active parameters

Unknown

Knowledge cutoff

Unknown

Context window

• 262,144 tokens the maximum position embeddings in the model configuration model configuration, read 2026-09-24
• 262,144 tokens the context length OpenRouter lists OpenRouter, read 2026-09-24

Longest output

• 230,400 tokens the largest output OpenRouter's first provider allows OpenRouter, read 2026-09-24

Tool calling

• Yes OpenRouter lists tools among the supported parameters OpenRouter, read 2026-09-24

Structured output

• Yes OpenRouter lists structured outputs among the supported parameters OpenRouter, read 2026-09-24

Reasoning controls

• Yes OpenRouter lists reasoning controls, with the efforts high, medium, low OpenRouter, read 2026-09-24

Inputs and outputs

text, image in, text out Hugging Face, read 2026-09-24

Good for

• Vision: Hugging Face files it under image-text-to-text Hugging Face, read 2026-09-24
• Reasoning: OpenRouter lists reasoning controls for it OpenRouter, read 2026-09-24

Prices

Run it on your own hardware

Weights are the sizes of the files a source lists, or an estimate from the parameter count where none does. Memory is an estimate: weights plus KV cache plus 512 MiB and 5 percent of the weights for runtime buffers. Check it against your hardware.

Start it with a local runtime

• Ollama

  ollama run hf.co/stepfun-ai/Step-3.7-Flash-GGUF:Q4_K_S

• LM Studio

  lms get stepfun-ai/Step-3.7-Flash-GGUF
  lms server start

• llama.cpp server

  llama-server -hf stepfun-ai/Step-3.7-Flash-GGUF:Q4_K_S --jinja

• vLLM

  vllm serve stepfun-ai/Step-3.7-Flash

• SGLang

  sglang serve --model-path stepfun-ai/Step-3.7-Flash --port 30000

Use it from your harness

Set up for DeepInfra with the model stepfun-ai/Step-3.7-Flash. Each endpoint page has the same setup for its own address.

{
  "$schema": "https://opencode.ai/config.json",
  "provider": {
    "deepinfra": {
      "npm": "@ai-sdk/openai-compatible",
      "name": "DeepInfra",
      "options": {
        "baseURL": "https://api.deepinfra.com/v1/openai",
        "apiKey": "{env:DEEPINFRA_TOKEN}"
      },
      "models": {
        "stepfun-ai/Step-3.7-Flash": {
          "name": "Step 3.7 Flash",
          "limit": {
            "context": 262144,
            "output": 230400
          }
        }
      }
    }
  }
}

{
  "providers": {
    "deepinfra": {
      "baseUrl": "https://api.deepinfra.com/v1/openai",
      "api": "openai-completions",
      "apiKey": "$DEEPINFRA_TOKEN",
      "models": [
        {
          "id": "stepfun-ai/Step-3.7-Flash"
        }
      ]
    }
  }
}

export ANTHROPIC_BASE_URL="https://api.deepinfra.com/anthropic"
export ANTHROPIC_AUTH_TOKEN="$DEEPINFRA_TOKEN"
export ANTHROPIC_MODEL="stepfun-ai/Step-3.7-Flash"
claude

Other ways to reach it

• Hugging Face, model stepfun-ai/Step-3.7-Flash
• Nvidia, model stepfun-ai/step-3.7-flash
• OpenRouter, model stepfun/step-3.7-flash
• Ollama, model hf.co/stepfun-ai/Step-3.7-Flash-GGUF:Q4_K_S

Published results

These are results other people published. Baltor did not run them and does not rank models by them.

• Results the maker published on the model card published by stepfun-ai Hugging Face, read 2026-09-24
• Artificial Analysis Coding Index: 39.6 published by Artificial Analysis OpenRouter, read 2026-09-24