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OpenAI

GPT 5 Mini

Name: GPT 5 Mini
Brand: OpenAI
Price: 0.25 USD
Availability: InStock

Going away: Dec 11, 2026

GPT 5 Mini is a reasoning model by OpenAI with function calling, prompt caching, structured output — designed for complex, multi-step problem solving where accuracy matters more than speed. It supports a 400K token context window with up to 128K tokens of output. Priced at $0.25 per million input tokens and $2 per million output tokens, it is one of the most cost-efficient options in its class. Access GPT 5 Mini through Inworld Router with OpenAI SDK compatibility, built-in failover, and intelligent routing across providers.

→Function CallingReasoningPrompt CachingResponse SchemareasoningCapabilityresponseFormatCapability

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-mini-a",
          "model_id": "openai/gpt-5-mini"
        },
        "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-mini-a",
                        "model_id": "openai/gpt-5-mini"
                    },
                    "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-mini-a",
              model_id: "openai/gpt-5-mini",
            },
            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 Mini pricing and providers

Access GPT 5 Mini 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	$0.25	$2.00	$0.025	—	400K	128K	+3

Prices in USD per 1M tokens.

Going away: Dec 11, 2026

Other OpenAI models available through Inworld

Compare GPT 5 Mini 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 5.6 Terra	$2.00	$12.00	$0.20	$2.50	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 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