Step 3.5 Flash

Overview

Step 3.5 Flash is StepFun's most capable open-source foundation model. Built on a sparse Mixture of Experts (MoE) architecture, it selectively activates only 11B of its 196B parameters per token.... Step 3.5 Flash is served through the PARROTSIGHT unified API at StepFun's list price, with the same authentication, metering and regional pinning (MY / SG / ID) as every native model. No separate provider account is required.

• 262K token context
• OpenAI-compatible endpoint — migrate with a two-line change
• Streaming (SSE) supported for all text outputs
• Billed at provider list price, metered per token

Capabilities

API

curl -X POST https://api.parrotsight.com/v1/chat/completions \
  -H "Authorization: Bearer $PS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"stepfun/step-3.5-flash","messages":[{"role":"system","content":"You are a concise bilingual assistant."},{"role":"user","content":"Summarise this quarter's platform metrics in Malay and English."}],"stream":true}'

Version history

1. v2026.1Latest2026-01-29

   Added to the PARROTSIGHT catalogue at StepFun list pricing.