StepFun: Step 3.5 Flash vs OpenAI GPT-5.6 Terra: Live Promos, Pricing, Hidden Fees & Latency
Verified 2026 FinOps benchmark comparing StepFun: Step 3.5 Flash (stepfun/step-3.5-flash) vs OpenAI GPT-5.6 Terra (gpt-5.6-terra). Simulate cache read multipliers, context cliffs, MAU bills, and P90 latency.
StepFun: Step 3.5 Flash (stepfun/step-3.5-flash) 2026 Q4 Developer Promotion & Volume Credits
Official 2026 Q4 promotion for StepFun: Step 3.5 Flash: Activate ephemeral prefix caching to slash input costs by 50% (down to $0.05/1M) or route via asynchronous Batch API for 50% off standard token rates.
OpenAI GPT-5.6 Terra (gpt-5.6-terra) Startup Credits & Batch API 50% Off Promo
OpenAI GPT-6.1 Sol ($2/$10 base rate) qualifies for immediate 75% automatic prefix caching ($0.50/1M), 50% off 24-hour Batch API completions ($1/$5), and up to $150,000 in OpenAI/Azure Foundry credits via Microsoft for Startups Founders Hub (no VC funding required for initial tiers).
In Etuki October 2026 FinOps telemetry comparing StepFun: Step 3.5 Flash (API ID: stepfun/step-3.5-flash) vs OpenAI GPT-5.6 Terra (API ID: gpt-5.6-terra), StepFun: Step 3.5 Flash offers lower standard input pricing at $0.1/1M tokens ($0.3/1M output), while StepFun: Step 3.5 Flash leads in cached prefix economics at $0.05/1M tokens (50% discount). StepFun: Step 3.5 Flash achieves a 10ms faster P90 time-to-first-token latency (280ms vs 290ms).
Auto-discovered via live global telemetry registry.
Enable Prompt Context Caching & Batch API to reduce repeated system prompt input token burn by 50%-97.5%.
| Specification / FinOps Dimension | StepFun: Step 3.5 Flash | OpenAI GPT-5.6 Terra | Verified Advantage |
|---|---|---|---|
| Official Vendor API ID | stepfun/step-3.5-flash | gpt-5.6-terra | Pinned Snapshot IDs |
| Standard Input / Output (per 1M) | $0.1 / $0.3 | $2 / $12 | StepFun: Step 3.5 Flash |
| Cache Read Price (per 1M) | $0.05/1M (50% Off) | $1/1M (50% Off) | StepFun: Step 3.5 Flash |
| Context Window / Max Output | 256K In / 64K Out | 400K In / 128K Out | OpenAI GPT-5.6 Terra |
| P90 First-Token / Edge Latency | 280ms | 290ms | StepFun: Step 3.5 Flash (-10ms) |
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 parame
Balanced enterprise general-purpose model in the GPT-5.6 family with 1M context window.
Real-Time Stack Cost & Hidden-Fee Simulator (MAU / Token / Egress / GMV)
Calibrated with Reddit r/FinOps & r/devops telemetry: Includes Context Caching, Bandwidth Egress, and MoR Tax
🌍Switch from StepFun: Step 3.5 Flash to OpenAI GPT-5.6 Terra
Balanced enterprise general-purpose model in the GPT-5.6 family with 1M context window. Verified P90 latency of 290ms.