The Orchestrator › Models › StepFun
StepFun: Step 5 Preview
Step 5 Preview is StepFun's flagship model for agentic work, built on a sparse Mixture-of-Experts architecture (27B active / 600B total parameters). It performs strongly in software engineering and professional...
Specifications
| Provider | StepFun |
| Model ID | stepfun/step-5-preview |
| Context window | 1M tokens (1,000,000) |
| Modalities | text + image + video → text |
| Tokenizer | Other |
| Router sources | OpenRouter, TrustedRouter, Vercel AI Gateway |
| Released | 2026-10-08 |
| Tracked since | 2026-11-14 |
| Popularity | #1 by usage · peak 77.6% spend share in an OpenRouter category |
| Reasoning | Mandatory |
Pricing (per million tokens)
| Variant | Source | API ID | Input | Output | Context |
|---|---|---|---|---|---|
| standard | OpenRouter | stepfun/step-5-preview | $1.00 | $2.70 | 1M |
| standard | TrustedRouter | stepfun-ai/step-5-preview | $1.06 | $2.85 | 1.0M |
| standard | Vercel AI Gateway | stepfun/step-5-preview | $1.00 | $2.70 | 1M |
Recorded price history
| Date | Input / 1M | Output / 1M | Context |
|---|---|---|---|
| 2026-11-14 | $1.00 | $2.70 | 1M |
| 2026-11-14 | $1.00 | $2.70 | 1.0M |
| 2026-11-14 | $1.06 | $2.85 | 1.0M |
| 2026-11-14 | $1.06 | $2.85 | 1M |
| 2026-11-14 | $1.00 | $2.70 | 1M |
Capabilities
Vision (image input)Video inputAgentic tool useStructured outputsReasoning (always on)1M+ context windowControllable reasoningNo content storage (attested)Zero data retention
Trust flags come from TrustedRouter's per-provider attestations.
Supported parameters
frequency_penalty, include_reasoning, logprobs, max_tokens, min_p, presence_penalty, reasoning, reasoning_effort, repetition_penalty, response_format, seed, stop, structured_outputs, temperature, tool_choice, tools, top_k, top_logprobs, top_p