Inception: Mercury 3 vs StepFun: Step 3.7 Flash: Live Promos, Pricing, Hidden Fees & Latency
Inception: Mercury 3 (inception/mercury-3) 2026 Q4 Developer Promotion & Volume Credits
Official 2026 Q4 promotion for Inception: Mercury 3: 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.
StepFun: Step 3.7 Flash (stepfun/step-3.7-flash) 2026 Q4 Developer Promotion & Volume Credits
Official 2026 Q4 promotion for StepFun: Step 3.7 Flash: Activate ephemeral prefix caching to slash input costs by 50% (down to 0.1/1M) or route via asynchronous Batch API for 50% off standard token rates.
In Etuki October 2026 FinOps telemetry comparing Inception: Mercury 3 (API ID: inception/mercury-3) vs StepFun: Step 3.7 Flash (API ID: stepfun/step-3.7-flash), Inception: Mercury 3 offers lower standard input pricing at $0.1/1M tokens ($0.35/1M output), while Inception: Mercury 3 leads in cached prefix economics at $0.05/1M tokens (50% discount). Inception: Mercury 3 achieves a 0ms faster P90 time-to-first-token latency (280ms vs 280ms).
Auto-discovered via live global telemetry registry.
Auto-discovered via live global telemetry registry.
| Specification / FinOps Dimension | Inception: Mercury 3 | StepFun: Step 3.7 Flash | Verified Advantage |
|---|---|---|---|
| Official Vendor API ID | inception/mercury-3 | stepfun/step-3.7-flash | Pinned Snapshot IDs |
| Standard Input / Output (per 1M) | $0.1 / $0.35 | $0.2 / $1.15 | Inception: Mercury 3 |
| Cache Read Price (per 1M) | $0.05/1M (50% Off) | $0.1/1M (50% Off) | Inception: Mercury 3 |
| Context Window / Max Output | 977K In / 128K Out | 256K In / 225K Out | StepFun: Step 3.7 Flash |
| P90 First-Token / Edge Latency | 280ms | 280ms | Inception: Mercury 3 (-0ms) |
Mercury 3 is a diffusion-based language model from Inception, and the lab's most capable model to date. It is suited for agentic workflows and real-time applications where latency
Step 3.7 Flash is StepFun's latest high-efficiency multimodal Mixture-of-Experts model. It pairs a 196B-parameter language backbone with a vision encoder for native image and video
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 Inception: Mercury 3 to StepFun: Step 3.7 Flash
Step 3.7 Flash is StepFun's latest high-efficiency multimodal Mixture-of-Experts model. It pairs a 196B-parameter language backbone with a vision encoder for native image and video Verified P90 latency of 280ms.