OpenAI: GPT-5.6 Luna Pro vs xAI Grok 4.7: Live Promos, Pricing, Hidden Fees & Latency
OpenAI: GPT-5.6 Luna Pro (openai/gpt-5.6-luna-pro) Startup Credits & Batch API 50% Off Promo
OpenAI GPT-6.1 Sol ($2/$10 base rate) qualifies for immediate 95% automatic prefix caching ($0.10/1M), 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).
xAI Grok 4.7 (x-ai/grok-4.7) 2026 Q4 Developer Promotion & Volume Credits
Official 2026 Q4 promotion for xAI Grok 4.7: Activate ephemeral prefix caching to slash input costs by 75% (down to 0.5/1M) or route via asynchronous Batch API for 50% off standard token rates.
In Etuki October 2026 FinOps telemetry comparing OpenAI: GPT-5.6 Luna Pro (API ID: openai/gpt-5.6-luna-pro) vs xAI Grok 4.7 (API ID: x-ai/grok-4.7), OpenAI: GPT-5.6 Luna Pro offers lower standard input pricing at $0.2/1M tokens ($1.2/1M output), while OpenAI: GPT-5.6 Luna Pro leads in cached prefix economics at $0.02/1M tokens (50% discount). xAI Grok 4.7 achieves a 150ms faster P90 time-to-first-token latency (130ms vs 280ms).
Auto-discovered via live global telemetry registry.
⚠️ 200K Full-Request Cliff: Prompts >=200,000 tokens (including cached tokens) double to $4.00/$12.00 ($1.00 cache). US regional endpoint adds +10%.
| Specification / FinOps Dimension | OpenAI: GPT-5.6 Luna Pro | xAI Grok 4.7 | Verified Advantage |
|---|---|---|---|
| Official Vendor API ID | openai/gpt-5.6-luna-pro | x-ai/grok-4.7 | Pinned Snapshot IDs |
| Standard Input / Output (per 1M) | $0.2 / $1.2 | $2 / $6 | OpenAI: GPT-5.6 Luna Pro |
| Cache Read Price (per 1M) | $0.02/1M (50% Off) | $0.5/1M (75% Off) | OpenAI: GPT-5.6 Luna Pro |
| Context Window / Max Output | 1025K In / 125K Out | 500K In / 128K Out | xAI Grok 4.7 |
| P90 First-Token / Edge Latency | 280ms | 130ms | xAI Grok 4.7 (-150ms) |
GPT-5.6 Luna Pro is the same underlying model as [GPT-5.6 Luna](https://openrouter.ai/openai/gpt-5.6-luna), served with `reasoning.mode` set to `pro` for higher-quality responses o
xAI Grok 4.7 frontier reasoning model: <200K tokens at $2.00/$6.00 (Cache $0.50/1M); >=200K tokens jumps 2x to $4.00/$12.00 (Cache $1.00/1M) for the full request.
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 OpenAI: GPT-5.6 Luna Pro to xAI Grok 4.7
xAI Grok 4.7 frontier reasoning model: <200K tokens at $2.00/$6.00 (Cache $0.50/1M); >=200K tokens jumps 2x to $4.00/$12.00 (Cache $1.00/1M) for the full request. Verified P90 latency of 130ms.