GPT-5.6 Terra vs GPT-5.6 Luna Codex credit cost
On a daily-coding request, GPT-5.6 Terra costs about 0.8 Codex credits ($0.03) versus 0.1 credits ($0.00) for GPT-5.6 Luna, so GPT-5.6 Terra costs about 10x as much. Both meter at $0.04 per credit, i.e. exact OpenAI API rates. Verified 2026-08-03.
| GPT-5.6 Terra | GPT-5.6 Luna | |
|---|---|---|
| Input, credits / 1M | 50 | 5 |
| Output, credits / 1M | 300 | 30 |
| API rate in / out, $ / 1M | $2.00 / $12.00 | $0.20 / $1.20 |
| Daily-coding request | 0.8 cr ($0.03) | 0.1 cr ($0.00) |