OpenAI

GPT 5.6 Luna

Name: GPT 5.6 Luna
Brand: OpenAI
Price: 1 USD
Availability: InStock

GPT 5.6 Luna is a reasoning model by OpenAI with vision, function calling, prompt caching, structured output — designed for complex, multi-step problem solving where accuracy matters more than speed. It supports a 1.1M token context window with up to 128K tokens of output. Priced at $1 per million input tokens and $6 per million output tokens. Access GPT 5.6 Luna through Inworld Router with OpenAI SDK compatibility, built-in failover, and intelligent routing across providers.

→Function CallingReasoningPrompt CachingResponse SchemaVisionreasoningCapabilityresponseFormatCapability

Use This Model

Step 1 — Create Router

curl --location 'https://api.inworld.ai/router/v1/routers' \
--header 'Authorization: Basic <your-api-key>' \
--header 'Content-Type: application/json' \
--data '{
  "name": "compare-frontier-models",
  "defaultRoute": {
    "route_id": "default",
    "variants": [
      {
        "variant": {
          "variant_id": "openai/gpt-5.6-luna-a",
          "model_id": "openai/gpt-5.6-luna"
        },
        "weight": 33
      },
      {
        "variant": {
          "variant_id": "openai/gpt-3.5-turbo-b",
          "model_id": "openai/gpt-3.5-turbo"
        },
        "weight": 33
      },
      {
        "variant": {
          "variant_id": "openai/gpt-4.1-c",
          "model_id": "openai/gpt-4.1"
        },
        "weight": 34
      }
    ]
  }
}'

import requests

response = requests.post(
    "https://api.inworld.ai/router/v1/routers",
    headers={
        "Authorization": "Basic <your-api-key>",
        "Content-Type": "application/json",
    },
    json={
        "name": "compare-frontier-models",
        "defaultRoute": {
            "route_id": "default",
            "variants": [
                {
                    "variant": {
                        "variant_id": "openai/gpt-5.6-luna-a",
                        "model_id": "openai/gpt-5.6-luna"
                    },
                    "weight": 33
                },
                {
                    "variant": {
                        "variant_id": "openai/gpt-3.5-turbo-b",
                        "model_id": "openai/gpt-3.5-turbo"
                    },
                    "weight": 33
                },
                {
                    "variant": {
                        "variant_id": "openai/gpt-4.1-c",
                        "model_id": "openai/gpt-4.1"
                    },
                    "weight": 34
                }
            ]
        }
    },
)
print(response.json())

const response = await fetch(
  "https://api.inworld.ai/router/v1/routers",
  {
    method: "POST",
    headers: {
      Authorization: "Basic <your-api-key>",
      "Content-Type": "application/json",
    },
    body: JSON.stringify({
      name: "compare-frontier-models",
      defaultRoute: {
        route_id: "default",
        variants: [
          {
            variant: {
              variant_id: "openai/gpt-5.6-luna-a",
              model_id: "openai/gpt-5.6-luna",
            },
            weight: 33,
          },
          {
            variant: {
              variant_id: "openai/gpt-3.5-turbo-b",
              model_id: "openai/gpt-3.5-turbo",
            },
            weight: 33,
          },
          {
            variant: {
              variant_id: "openai/gpt-4.1-c",
              model_id: "openai/gpt-4.1",
            },
            weight: 34,
          },
        ],
      },
    }),
  }
);
const data = await response.json();
console.log(data);

Step 2 — Chat Completion

curl --location 'https://api.inworld.ai/v1/chat/completions' \
--header 'Authorization: Basic <your-api-key>' \
--header 'Content-Type: application/json' \
--data '{
  "model": "inworld/compare-frontier-models",
  "messages": [{"role": "user", "content": "Hello!"}]
}'

GPT 5.6 Luna pricing and providers

Access GPT 5.6 Luna through OpenAI via Inworld Router or Realtime API. By using the AI provider(s) below you acknowledge you reviewed and agree to their terms listed in the Legal section under the AI provider's name.

					Capabilities	Input modalities	Output modalities
OpenAI	1.1M	128K	$1.00	$6.00	+4

Other OpenAI models available through Inworld

Compare GPT 5.6 Luna with other OpenAI models available through Inworld Router or Realtime API.

					Capabilities
GPT 3.5 Turbo	16.4K	4.1K	$0.50	$1.50
GPT 4.1	1M	32.8K	$2.00	$8.00	+2
GPT 4.1 Mini	1M	32.8K	$0.40	$1.60	+2
GPT 4.1 Nano	1M	32.8K	$0.10	$0.40	+1
GPT 4.1 Nano 2025 04 14	1M	32.8K	$0.10	$0.40	+2
GPT 4o	128K	16.4K	$2.50	$10.00	+2
GPT 4o 2024 08 06	128K	16.4K	$2.50	$10.00	+2
GPT 4o Mini	128K	16.4K	$0.15	$0.60	+2
GPT 5 Mini	272K	128K	$0.25	$2.00	+3
GPT 5 Nano	272K	128K	$0.05	$0.40	+3
GPT 5.1	272K	128K	$1.25	$10.00	+4
GPT 5.2	272K	128K	$1.75	$14.00	+4
GPT 5.4	1.1M	128K	$2.50	$15.00	+4
GPT 5.4 Mini	272K	128K	$0.75	$4.50	+4
GPT 5.4 Nano	272K	128K	$0.20	$1.25	+4
GPT 5.5	1.1M	128K	$5.00	$30.00	+4
GPT 5.6 Sol	1.1M	128K	$5.00	$30.00	+4
GPT 5.6 Terra	1.1M	128K	$2.50	$15.00	+4
GPT Image 2	32.8K	32.8K	$8.00	$30.00
Openai/gpt Oss 120b	131.1K	131.1K	$0.039	$0.19	+3
Openai/gpt Oss 120b Turbo	131.1K	—	$0.15	$0.60	+2
Openai/gpt Oss 20b	131.1K	32.8K	$0.075	$0.30	+3
Openai/gpt Oss Safeguard 20b	131.1K	65.5K	$0.075	$0.30	+3

View all models

Start building with GPT 5.6 Luna

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