Step 3.5 Flash

Name: Step 3.5 Flash
Brand: stepfun
SKU: stepfun/step-3.5-flash
Price: 0.105 USD
Availability: InStock

stepfun/step-3.5-flash

text in · text out · 262,144 context · 65,536 max output

toolsschemareasoningno-trainShow prices also in

Effective cost per 1k requestsInput tokens 2,000Output tokens 500Cached share 50%

cost = p_in·(input − cached) + p_cache_read·cached + p_out·output + p_req; cached tokens are the prefix a sticky endpoint already holds (part2b §9.3), which is why the cheapest list price is not always the cheapest request.

Provider	Region · quant	Context / max out	Input / M	Output / M	Cache read / write	Markup	Per 1k req	Uptime 30 d	TTFT p50 / p95	Throughput	Last 24 h	Fidelity	Data	Capabilities	Status
OpenRouter	global · unknown	262,144 / 65,536	$0.105	$0.315	— / —	+5.0%	$0.367	—	—	—	no traffic	—	no-train 30 d	model default	active

Quick start

curl https://api.ai.ml/v1/chat/completions \
  -H "Authorization: Bearer $AIML_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"stepfun/step-3.5-flash","messages":[{"role":"user","content":"Say hello"}]}'

Get a key in the console

Changelog

new_model model stepfun/step-3.5-flash added (active); endpoint ep_openrouter_step-3.5-flash_global (stepfun/step-3.5-flash) added as active; price input 0.105 output 0.315 USD/M 10/5/2026