GPT-5.6 API pricing — Sol, Terra, Luna
OpenAI’s GPT-5.6 family has three list-price tiers. After the July 30, 2026 cut, Luna is $0.20 / $1.20 per 1M (−80%), Terra is $2 / $12 (−20%), and Sol stays the expensive flagship lane. The bare alias gpt-5.6 routes to Sol — not Luna.
Tier table (API list)
| Tier | Model ID | Input / 1M | Output / 1M |
|---|---|---|---|
| Luna | gpt-5.6-luna | $0.20 | $1.20 |
| Terra | gpt-5.6-terra | $2 | $12 |
| Sol | gpt-5.6-sol / alias gpt-5.6 | Flagship | Flagship |
Source of truth: platform.openai.com/docs/pricing. Cached Luna input is listed around $0.02 / 1M. Context windows are ~1.05M for the family — usable recall still varies by tier and task.
Same-token sketch (why Luna exists)
For 10M input + 5M output with no cache:
- Luna: ≈ $8
- Terra: ≈ $80 (~10× Luna)
That ~10× gap is why Luna became the default cheap OpenAI lane for volume agents after the cut. Sol remains the escalation path for hardest tasks — never the silent default when you meant Luna.
Alias gotcha and hosted defaults
Pin gpt-5.6-luna, gpt-5.6-terra, or gpt-5.6-sol. The short id gpt-5.6 is Sol — teams that “upgrade to 5.6” without reading the alias often bill-shock. Longer note: alias routes to Sol.
On CloudAxis / CloudyBot hosted chat, Auto Mode is Luna on every plan — operators do not pick a SKU from a dropdown. Use this page when you call OpenAI (or a router) directly.
Tier deep-dive: Sol vs Terra vs Luna · Luna hub: cloudaxis.ai/gpt-5-6-luna.
FAQ
What is GPT-5.6 Luna’s API price?
After the July 30, 2026 cut: $0.20 input and $1.20 output per 1M tokens (cached input about $0.02). Confirm on OpenAI’s pricing page.
Does gpt-5.6 mean Luna?
No. The bare gpt-5.6 alias routes to Sol (flagship). Use gpt-5.6-luna explicitly for the cheap tier.
How much cheaper is Luna than Terra?
On list rates Terra is about $2/$12 vs Luna $0.20/$1.20 — roughly 10× on a balanced 2:1 input:output mix before caching.
Related
Luna vs Haiku · Luna vs DeepSeek · Cheapest LLM API · OpenAI provider · Cost calculator.