GPT-5.6 Luna

by OpenAI

GPT-5.6 model optimized for cost-sensitive, high-volume workloads. 1M context window with reasoning.

Key info

Input
Output
Features
Context window
1.1M
Max output
128K
Input price
$1.00 /1M
Output price
$6.00 /1M
  • US residency available
  • Zero data retention via Enterprise
  • No training by default
  • GDPR DPA available

Available routes

GPT-5.6 Luna runs on 1 route through the Opper gateway. Compare residency, ZDR, and training posture at a glance β€” full data-handling detail per route below.

ProviderRegionZero data retentionTrainingInputOutput
USEnterpriseNo$1.00$6.00

Training posture across routes: No training on prompts by default.

Data handling per route

Each route hosting GPT-5.6 Luna has its own privacy posture, residency, and GDPR terms. Postures are maintained by Opper with a last-verification timestamp.

OpenAI β€” United StatesπŸ‡ΊπŸ‡Έ

Zero data retention is available via Opper Enterprise contract. No training on customer data. US; SCCs; DPA available.

Zero data retention
Available via Opper Enterprise contract.
Training
No training on customer data.
Logging
Abuse monitoring (30-day retention)
Third-party access
None disclosed
GDPR DPA
DPA available
Transfer mechanism
SCCs

Benchmarks

Independent benchmark scores β€” composite indices for reasoning, coding, and math, plus individual eval scores where available.

Global rank#15 of 557 LLMs
TierFrontier
Output speed231 tok/s
First token69.11s
Intelligence Index51.2
Coding Index71.4
Reasoning & knowledge
GPQA Diamond
91%
Humanity's Last Exam
37%
Long-context reasoning
74%
Coding
SciCode
53%

Get started

Call GPT-5.6 Luna through the Opper gateway with one API key. Let your coding agent set it up, or call it directly β€” Opper is drop-in compatible with the OpenAI, Anthropic, and Google AI SDKs.

Set it up with your agent

Copy this and paste it into a coding agent like Claude Code, Cursor or Codex and it'll wire up Opper for you.

Or call it directly

import OpenAI from "openai";
const client = new OpenAI({
apiKey: process.env.OPPER_API_KEY,
baseURL: "https://api.opper.click/v3/compat",
});
const completion = await client.chat.completions.create({
model: "openai/gpt-5.6-luna",
messages: [{ role: "user", content: "Hello" }],
});
console.log(completion.choices[0].message.content);

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OpenAI: GPT-5.6 Luna - API Pricing & Benchmarks