Access and Use step3 via OpenRouter

Step3 is a cutting-edge multimodal reasoning model—built on a Mixture-of-Experts architecture with 321B total parameters and 38B active. It is designed end-to-end to minimize decoding costs while delivering top-tier performance in vision–language reasoning. Through the co-design of Multi-Matrix Factorization Attention (MFA) and Attention-FFN Disaggregation (AFD), Step3 maintains exceptional efficiency across both flagship and low-end accelerators.

StepFun: Step3 Overview

Full NameStepFun: Step3
ProviderStepFun
Model IDstepfun-ai/step3
Release DateAug 28, 2025
Context Window65,536 tokens
Pricing /1M tokens$0.00000057 for input
$0.00000142 for output
Supported Input Typesimage, text
Supported Parametersfrequency_penaltyinclude_reasoningreasoningresponse_formatstructured_outputstemperaturetool_choicetoolstop_ktop_p

Complete Setup Guide

1

Create OpenRouter Account

  1. Visit openrouter.ai
  2. Click "Sign In" and create an account (free)
  3. Verify your email address
  4. You'll receive $1 in free credits to test models
2

Get Your OpenRouter API Key

  1. Log in to OpenRouter dashboard
  2. Go to "API Keys" section in the menu
  3. Click "Create API Key"
  4. Give it a name (e.g., "TypingMind")
  5. Copy your API key (starts with "sk-or-v1-...")
OpenRouter API Keys
3

Add Credits to OpenRouter (Optional)

  1. Go to "Credits" in OpenRouter dashboard
  2. Click "Add Credits"
  3. Choose amount ($5 minimum, $20 recommended for testing)
  4. Complete payment (credit card or crypto)
  5. Credits never expire!
4

Configure TypingMind with OpenRouter API Key

Method 1: Direct Import (Recommended)

  1. Open TypingMind in your browser
  2. Click the "Settings" icon (gear symbol)
  3. Navigate to "Manage Models" section
  4. Click "Add Custom Model"
  5. Select "Import OpenRouter" from the options
  6. Enter your OpenRouter API key from Step 1
  7. Click "Check API Key" to verify the connection
  8. Choose which models you want to add from the list (you can add multiple at once)
  9. Click "Import Models" to complete the setup
The best frontend AI chat for OpenRouter API Key

Method 2: Manual Custom Model Setup

  1. Open TypingMind in your browser
  2. Click the "Settings" icon (gear symbol)
  3. Navigate to "Models" section
  4. Click "Add Custom Model"
  5. Fill in the model information:
    Name: stepfun-ai/step3 via OpenRouter (or your preferred name)
    Endpoint: https://openrouter.ai/api/v1/chat/completions
    Model ID: stepfun-ai/step3
    Context Length: Enter the model's context window (e.g., 65536 for stepfun-ai/step3)
    OpenRouter Endpoint URL input fieldstepfun-ai/step3https://openrouter.ai/api/v1/chat/completionsstepfun-ai/step3 via OpenRouterhttps://www.typingmind.com/model-logo.webp65536
  6. Add custom headers by clicking "Add Custom Headers" in the Advanced Settings section:
    Authorization: Bearer <OPENROUTER_API_KEY>:
    X-Title: typingmind.com
    HTTP-Referer: https://www.typingmind.com
  7. Enable "Support Plugins (via OpenAI Functions)" if the model supports the "functions" or "tool_calls" parameter, or enable "Support OpenAI Vision" if the model supports vision.
  8. Click "Test" to verify the configuration
  9. If you see "Nice, the endpoint is working!", click "Add Model"
5

Start chatting with stepfun-ai/step3

Now you can start chatting with the stepfun-ai/step3 model via OpenRouter on TypingMind:

  • Select your preferred stepfun-ai/step3 model from the model dropdown menu
  • Start typing your message in the chat input
  • Enjoy faster responses and better features than the official interface
  • Switch between different AI models as needed
The best frontend AI chat for stepfun-ai/step3 via OpenRouter API KeyThe best frontend AI chat for stepfun-ai/step3 via OpenRouter API Keystepfun-ai/step3The best frontend AI chat for stepfun-ai/step3 via OpenRouter API Key

Pro tips for better results:

Why TypingMind + OpenRouter?

  • Best-in-class UI: TypingMind's interface is far superior to standard chat UIs
  • Model flexibility: Switch between StepFun: Step3 and 200+ models instantly
  • Cost control: Pay only for what you use through OpenRouter
  • One-time purchase: Buy TypingMind once, use forever with any OpenRouter model
  • Data privacy: Your conversations stored locally, not on external servers

Try TypingMind for free now!

Frequently Asked Questions

Do I need a subscription to use StepFun: Step3?

No! Through OpenRouter, you pay only for what you use with no monthly subscription. Add credits to your OpenRouter account and they never expire. TypingMind is also a one-time purchase, not a subscription.

How much will it cost to use StepFun: Step3?

It costs 0.00000057 for input and 0.00000142 for output via OpenRouter. A typical conversation might cost $0.01-0.10 depending on length. Start with $5-10 in credits to test.

Can I use other models besides StepFun: Step3?

Yes! With OpenRouter + TypingMind, you get access to 200+ models including GPT-4, Claude, Gemini, Llama, Mistral, and many more. Switch between them instantly in TypingMind.

Is my data private and secure?

Yes! TypingMind stores conversations locally (web version in browser, desktop version on your device). OpenRouter handles API calls securely and doesn't train on your data. Check each provider's data policy for specifics.

Can I use StepFun: Step3 for commercial projects?

Yes! Check StepFun's terms of service for specific commercial use policies. OpenRouter and TypingMind both support commercial use.

What if StepFun: Step3 is unavailable?

OpenRouter allows you to configure fallback models. If StepFun: Step3 is down, it can automatically route to your backup choice. You can also manually switch models in TypingMind anytime.

How do I cancel or get a refund?

OpenRouter: No subscriptions to cancel. Unused credits remain in your account forever.