StepFun: Step 3.5 Flash vs OpenAI GPT-6 Astra: Live Promos, Pricing, Hidden Fees & Latency
Verified 2026 FinOps benchmark comparing StepFun: Step 3.5 Flash (stepfun/step-3.5-flash) vs OpenAI GPT-6 Astra (gpt-6-astra). 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-6 Astra (gpt-6-astra) 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-6 Astra (API ID: gpt-6-astra), 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 140ms faster P90 time-to-first-token latency (280ms vs 420ms).
Auto-discovered via live global telemetry registry.
Billed at $10/$50 (<272K) and jumps to $20/$75 (>272K). Reserve strictly for hard computer-use orchestration.
| Specification / FinOps Dimension | StepFun: Step 3.5 Flash | OpenAI GPT-6 Astra | Verified Advantage |
|---|---|---|---|
| Official Vendor API ID | stepfun/step-3.5-flash | gpt-6-astra | Pinned Snapshot IDs |
| Standard Input / Output (per 1M) | $0.1 / $0.3 | $10 / $50 | StepFun: Step 3.5 Flash |
| Cache Read Price (per 1M) | $0.05/1M (50% Off) | $2.5/1M (75% Off) | StepFun: Step 3.5 Flash |
| Context Window / Max Output | 256K In / 64K Out | 1000K In / 128K Out | OpenAI GPT-6 Astra |
| P90 First-Token / Edge Latency | 280ms | 420ms | StepFun: Step 3.5 Flash (-140ms) |
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
OpenAI most powerful computer-use and autonomous multi-agent flagship model built for zero-failure enterprise tasks.
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-6 Astra
OpenAI most powerful computer-use and autonomous multi-agent flagship model built for zero-failure enterprise tasks. Verified P90 latency of 420ms.