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  1. Models
  2. Text
  3. Stepfun Ai

Step 3.5 Flash 2603

Step 3.5 Flash 2603 is optimized for high-frequency agentic and coding workflows with improved token efficiency and faster reasoning. NOTE: This model runs via StepFun, which may log and train on your prompts.

  • Reasoning

Added Apr 14, 2026

Pricing

Auto routing · per 1M tokens
Input
$0.10
Output
$0.30
Compare provider prices

Specifications

Context window
256K
Max output
256K
Parameters
196B / 11B
Total / active
Avg output (7d)
3K tokens
Longer than 96% of models

Benchmarks

No public benchmark scores for this model yet.

Providers

Auto routing is available for this model. Explicit provider selection is not available.

Auto
Auto
Recommended
$0.10$0.30N/AN/AN/A
Batch API
ProviderInputOutputCached input
Auto
Autostepfun-ai/step-3.5-flash-2603
$0.10/M$0.30/MN/A

Batch rows for this model use normal routing and cost the same as standard API requests. Set provider in a row to choose a provider.

Reliability

Related text models

Compare Step 3.5 Flash 2603 with similar models from the same provider or model family.

Step 3.5 Flash

stepfun-ai/step-3.5-flash

StepFun's most capable open-source reasoning model with visible reasoning traces. Built on a sparse Mixture-of-Experts architecture with 196B total parameters and only 11B active per token, it achieves frontier-level performance in math, logic, and agentic coding while reaching up to 350 tokens/sec. Supports 256K context. NOTE: This model runs via StepFun, which may log and train on your prompts.

Step 3.7 Flash Thinking

stepfun/step-3.7-flash:thinking

Step 3.7 Flash Thinking is StepFun's high-efficiency multimodal MoE model with visible reasoning enabled for deeper agentic coding, long-context reasoning, tool use, and native image/video understanding.

Step 5 Preview

stepfun/step-5-preview

Step 5 Preview is StepFun's 600B sparse MoE frontier model for production-scale agents, activating 27B parameters per token. It is built for software engineering, long-horizon tool use, research, professional knowledge work, and finance, with native text, image, and video understanding and a 1M-token context window.

OrcaCyber MiniMax M3.1 Flash

orca/orcacyber-minimax-m3.1-flash

An OrcaCyber model for authorized security research, coding, and tool use. Reasoning is always enabled, with selectable effort. Supports a 262K-token context window, up to 131K output tokens, tool calling, and structured output. Accepts text input. Offensive work is permitted only within an authorized security engagement.

OrcaCyber Qwen3.8 Flash Next

orca/orcacyber-qwen3.8-flash-next

An OrcaCyber model for authorized security research, coding, and tool use. Accepts text and images, with reasoning enabled by default and an option to turn it off. Supports a 262K-token context window, up to 131K output tokens, tool calling, and structured output. Offensive work is permitted only within an authorized security engagement.

DeepSeek V4.1 Flash Heretic

pqhaz/DeepSeek-V4.1-Flash-1017-heretic

pqhaz's Heretic checkpoint of DeepSeek V4.1 Flash 1017, served by Sable at original mixed precision (FP8 dense/Engram and MXFP4 experts). Supports text and image input, tools, structured output, and optional reasoning. Separate from the DeAlign uncensored checkpoint.