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OpenAI

GPT 5.6 Terra

Name: GPT 5.6 Terra
Brand: OpenAI
Price: 2 USD
Availability: InStock

GPT 5.6 Terra 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 $2 per million input tokens and $12 per million output tokens. Access GPT 5.6 Terra 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-terra-a",
          "model_id": "openai/gpt-5.6-terra"
        },
        "weight": 33
      },
      {
        "variant": {
          "variant_id": "openai/gpt-4o-mini-b",
          "model_id": "openai/gpt-4o-mini"
        },
        "weight": 33
      },
      {
        "variant": {
          "variant_id": "openai/gpt-6-luna-c",
          "model_id": "openai/gpt-6-luna"
        },
        "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-terra-a",
                        "model_id": "openai/gpt-5.6-terra"
                    },
                    "weight": 33
                },
                {
                    "variant": {
                        "variant_id": "openai/gpt-4o-mini-b",
                        "model_id": "openai/gpt-4o-mini"
                    },
                    "weight": 33
                },
                {
                    "variant": {
                        "variant_id": "openai/gpt-6-luna-c",
                        "model_id": "openai/gpt-6-luna"
                    },
                    "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-terra-a",
              model_id: "openai/gpt-5.6-terra",
            },
            weight: 33,
          },
          {
            variant: {
              variant_id: "openai/gpt-4o-mini-b",
              model_id: "openai/gpt-4o-mini",
            },
            weight: 33,
          },
          {
            variant: {
              variant_id: "openai/gpt-6-luna-c",
              model_id: "openai/gpt-6-luna",
            },
            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 Terra pricing and providers

Access GPT 5.6 Terra 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	$2.00	$12.00	$0.20	$2.50	1.1M	128K	+4

Prices in USD per 1M tokens.

Other OpenAI models available through Inworld

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

							Capabilities
GPT 4o Mini	$0.15	$0.60	$0.075	—	128K	16.4K	+2
GPT 6 Luna	$0.10	$0.50	$0.01	$0.125	1.1M	128K	+4
GPT 5.6 Luna	$0.20	$1.20	$0.02	$0.25	1.1M	128K	+4
GPT 6.1 Sol	$2.00	$10.00	$0.10	$2.50	1.1M	128K	+4
GPT 6 Astra	$10.00	$50.00	$1.00	$12.50	1.1M	128K	+4
GPT 6 Luna:fast	$0.20	$1.00	$0.02	$0.25	1.1M	128K	+4
GPT 6 Sol	$2.00	$10.00	$0.20	$2.50	1.1M	128K	+4
GPT 5.6 Sol	$5.00	$30.00	$0.50	$6.25	1.1M	128K	+4
GPT 5.5	$5.00	$30.00	$0.50	—	1.1M	128K	+4
GPT 5.4	$2.50	$15.00	$0.25	—	1.1M	128K	+4
GPT 5.4 Mini	$0.75	$4.50	$0.075	—	400K	128K	+4
GPT 5.4 Nano	$0.20	$1.25	$0.02	—	400K	128K	+4
GPT 5.2	$1.75	$14.00	$0.175	—	400K	128K	+4
GPT 5.1	$1.25	$10.00	$0.125	—	400K	128K	+4
GPT 5 Mini	$0.25	$2.00	$0.025	—	400K	128K	+3
GPT 5 Nano	$0.05	$0.40	$0.005	—	400K	128K	+3
GPT 4o	$2.50	$10.00	$1.25	—	128K	16.4K	+2
GPT 4o 2024 08 06	$2.50	$10.00	$1.25	—	128K	16.4K	+2
GPT 4.1	$2.00	$8.00	$0.50	—	1M	32.8K	+2
GPT 4.1 Mini	$0.40	$1.60	$0.10	—	1M	32.8K	+2
GPT 4.1 Nano	$0.10	$0.40	$0.025	—	1M	32.8K	+1
GPT 4.1 Nano 2025 04 14	$0.10	$0.40	$0.025	—	1M	32.8K	+2
GPT 3.5 Turbo	$0.50	$1.50	—	—	16.4K	4.1K
GPT Image 2	$8.00	$30.00	$2.00	—	32.8K	32.8K
GPT Oss 120b	$0.037	$0.17	—	—	131.1K	131.1K	+2
GPT Oss 120b	$0.15	$0.60	$0.075	—	131.1K	32.8K	+3
GPT Oss 20b	$0.075	$0.30	$0.038	—	131.1K	32.8K	+3
GPT Oss Safeguard 20b	$0.075	$0.30	$0.038	—	131.1K	65.5K	+3