AI API Router Directory

StepFun's open platform exposes Step 3.7 Flash and Step 3.5 Flash reasoning models, a vision model and a full speech stack, priced per 1M tokens, per hour of audio or per 10,000 characters. Step 3.7 Flash is 1.35 CNY per 1M input tokens on a cache miss, 0.27 CNY cached input and 8.1 CNY output; Step 3.5 Flash is 0.7 / 0.14 / 2.1 CNY, and four audio preview models are marked limited-time free in the price table. Rate limits are tiered by cumulative top-up, from V0 with 5 concurrent requests, 10 RPM and 5,000,000 TPM at zero spend to V5 with 200,000 RPM at 10,000 CNY.

No numeric free grant is published on official pages (checked 2026-09-16); the billing doc confirms a gift-balance account is drawn down before paid balance but states no amount, while stepaudio-3-realtime-preview, stepaudio-3-chat-preview, stepaudio-3-gen-preview and stepaudio-3-music-preview are listed as limited-time free in the price table.