The lightest member of OpenAI's GPT-5.6 generation, GPT-5.6 Luna launched alongside Sol and Terra on July 9, 2026 and is tuned for speed and volume rather than maximum depth. It keeps the family traits, a 1.05 million token context window, 128K max output, reasoning support, vision, and structured output, in a much quicker package, and on agentic terminal benchmarks it performs on par with the previous GPT-5.5 generation. Luna is built for high-throughput work such as classification, summarization, extraction, and batch processing, where per-request speed compounds across millions of calls. Recall over very long inputs is where the bigger tiers pull ahead, so it fits best as the workhorse for shorter-context tasks at scale and as the fast layer in multi-model pipelines.
GPT-5.6 Luna runs on 2 different routes through the Opper gateway. Compare residency, ZDR, and training posture at a glance — full data-handling detail per route below.
| Provider | Region | Zero data retention | Training | Input | Output |
|---|---|---|---|---|---|
| Multi | Zero data retention | No | $0.20 | $1.20 | |
| US | Enterprise | No | $0.20 | $1.20 |
GPT-5.6 Luna runs on 2 independently monitored routes through the Opper gateway. A direct integration leaves you on one of them, the gateway serves whichever is healthy.
Measured over the last 30 days from each provider's official status feed via StatusGator. Refreshed hourly. See uptime for every provider Opper monitors.
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.
Zero data retention is on by default on Pay-as-you-go — no action required. No training on customer data. GLOBAL; SCCs; DPA available.
Zero data retention is available via Opper Enterprise contract. No training on customer data. US; SCCs; DPA available.
Independent benchmark scores — composite indices for reasoning, coding, and math, plus individual eval scores where available.
Call GPT-5.6 Luna through the Opper gateway with one API key. Let your coding agent set it up, or call it directly — Opper is drop-in compatible with the OpenAI, Anthropic, and Google AI SDKs.
Copy this and paste it into a coding agent like Claude Code, Cursor or Codex and it'll wire up Opper for you.
import OpenAI from "openai";const client = new OpenAI({apiKey: process.env.OPPER_API_KEY,baseURL: "https://api.opper.ai/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);
Side-by-side on privacy, EU hosting, pricing, and benchmarks.
