GPT-5.6 Luna

OpenAIMCP Tool CallReasoning

openai/gpt-5.6-lunaClosed API

Cost-efficient GPT-5.6 model for fast, high-volume workloads

Benchmark Pricing$0.20 / 1M in$1.20 / 1M out$0.02 cache read

Context: 1,050,000 tokens•Max Output: 128,000 tokens•Knowledge: 2026-02-16•Released: 2026-07-09

TECHNICAL SPECIFICATIONS

Context Window1,050,0001.1M tokens

Max Output128,000128K tokens

LicenseProprietaryCloud API only

Input Modalities

TextVisionPDF

Function / Tool CallingSupported (MCP Ready)

Structured OutputsGuaranteed Schema

MODEL CONTEXT PROTOCOL (MCP) READINESS

✓ GPT-5.6 Luna natively supports OpenAI / Anthropic format tool calling and is fully compatible with MCP servers and agent loops.

MCP Context Window Recommendations

With a context capacity of 1,050,000 tokens, this model can handle extremely large MCP resource manifests, complete database schemas, and multiple active server tool definitions simultaneously without degradation.

STANDARDIZED BENCHMARKS & EVALS

SWE-Bench Proresolve rate

62.7

Terminal-Benchsuccess rate

84.7

DeepSWEresolve rate

67.2

GPQA Diamondaccuracy

92.3

FrontierMathaccuracy

78.6

BrowseCompaccuracy

83.3

OSWorldsuccess rate

45.6

MMMU Proaccuracy

78.4

Agents' Last ExamUnit not reported

50.3

Toolathlonsuccess rate

53.4

Artificial Analysis Intelligence Indexindex score

51.2

Artificial Analysis Coding Agent Indexindex score

74.6

API CALL INVOCATION EXAMPLE

// Example: Calling GPT-5.6 Luna via OpenAI SDK
import OpenAI from "openai";

const client = new OpenAI({
  apiKey: process.env.OPENAI_API_KEY,
});

const response = await client.chat.completions.create({
  model: "openai/gpt-5.6-luna",
  messages: [{ role: "user", content: "Hello! Can you inspect MCP tools?" }],
});

console.log(response.choices[0].message.content);