GPT-5.5

Text Generation • OpenAI • Proxied

GPT-5.5 is OpenAI's flagship model with strong coding, reasoning, and multimodal capabilities.

Model Info
Context Window ↗	1,000,000 tokens
Terms and License	link ↗
More information	link ↗
Pricing	View pricing in the Cloudflare dashboard ↗

Usage

const response = await env.AI.run(
  'openai/gpt-5.5',
  {
    messages: [
      {
        role: 'user',
        content: 'What are the three laws of thermodynamics?',
      },
    ],
  },
  {
    gateway: { id: 'default' },
  }
)
console.log(response)

Input / Output JSON

Input
Output

{
    "messages": [
        {
            "role": "user",
            "content": "What are the three laws of thermodynamics?"
        }
    ]
}

{
    "text": "The **three laws of thermodynamics** are:\n\n1. **First Law of Thermodynamics** — **Energy is conserved**  \n   Energy cannot be created or destroyed, only transferred or transformed.  \n   In thermodynamic systems, this is often written as:  \n   **ΔU = Q - W**  \n   where:\n   - **ΔU** = change in internal energy  \n   - **Q** = heat added to the system  \n   - **W** = work done by the system  \n\n2. **Second Law of Thermodynamics** — **Entropy tends to increase**  \n   In any natural process, the total entropy of an isolated system never decreases.  \n   This means energy tends to spread out, and no heat engine can be 100% efficient.\n\n3. **Third Law of Thermodynamics** — **Entropy approaches a minimum at absolute zero**  \n   As the temperature of a perfect crystal approaches **0 Kelvin**, its entropy approaches **zero**.  \n   This also implies that absolute zero cannot be reached in a finite number of steps.\n\nThere is also a **Zeroth Law of Thermodynamics**, which is often listed before the first three:\n\n- If two systems are each in thermal equilibrium with a third system, they are in thermal equilibrium with each other.  \n- This is the basis for the concept of **temperature**.\n\nIf you want, I can also give a simple everyday explanation of each law."
}

Parameters

Input
Output

▶messages[]

arrayrequired

temperature

numberminimum: 0maximum: 2

max_tokens

numberexclusiveMinimum: 0

max_completion_tokens

numberexclusiveMinimum: 0

top_p

numberminimum: 0maximum: 1

frequency_penalty

numberminimum: -2maximum: 2

presence_penalty

numberminimum: -2maximum: 2

stream

boolean

▶stream_options{}

object

▶tools[]

array

tool_choice

response_format

string

object

string

created

number

model

string

▶choices[]

array

▶usage{}

object

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "properties": {
    "messages": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "role": {
            "type": "string",
            "enum": [
              "system",
              "developer",
              "user",
              "assistant",
              "tool"
            ]
          },
          "content": {
            "anyOf": [
              {
                "type": "string"
              },
              {
                "type": "null"
              },
              {
                "type": "array",
                "items": {}
              }
            ]
          }
        },
        "required": [
          "role",
          "content"
        ],
        "additionalProperties": {}
      }
    },
    "temperature": {
      "type": "number",
      "minimum": 0,
      "maximum": 2
    },
    "max_tokens": {
      "type": "number",
      "exclusiveMinimum": 0
    },
    "max_completion_tokens": {
      "type": "number",
      "exclusiveMinimum": 0
    },
    "top_p": {
      "type": "number",
      "minimum": 0,
      "maximum": 1
    },
    "frequency_penalty": {
      "type": "number",
      "minimum": -2,
      "maximum": 2
    },
    "presence_penalty": {
      "type": "number",
      "minimum": -2,
      "maximum": 2
    },
    "stream": {
      "type": "boolean"
    },
    "stream_options": {
      "type": "object",
      "properties": {
        "include_usage": {
          "type": "boolean"
        }
      },
      "additionalProperties": false
    },
    "tools": {
      "type": "array",
      "items": {}
    },
    "tool_choice": {},
    "response_format": {}
  },
  "required": [
    "messages"
  ],
  "additionalProperties": {}
}

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "properties": {
    "id": {
      "type": "string"
    },
    "object": {
      "type": "string"
    },
    "created": {
      "type": "number"
    },
    "model": {
      "type": "string"
    },
    "choices": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "index": {
            "type": "number"
          },
          "message": {
            "type": "object",
            "properties": {
              "role": {
                "type": "string"
              },
              "content": {
                "anyOf": [
                  {
                    "type": "string"
                  },
                  {
                    "type": "null"
                  }
                ]
              },
              "tool_calls": {
                "type": "array",
                "items": {}
              }
            },
            "required": [
              "role"
            ],
            "additionalProperties": {}
          },
          "finish_reason": {
            "anyOf": [
              {
                "type": "string"
              },
              {
                "type": "null"
              }
            ]
          }
        },
        "required": [
          "index",
          "message",
          "finish_reason"
        ],
        "additionalProperties": {}
      }
    },
    "usage": {
      "type": "object",
      "properties": {
        "prompt_tokens": {
          "type": "number"
        },
        "completion_tokens": {
          "type": "number"
        },
        "total_tokens": {
          "type": "number"
        }
      },
      "required": [
        "prompt_tokens",
        "completion_tokens",
        "total_tokens"
      ],
      "additionalProperties": {}
    }
  },
  "required": [
    "id",
    "object",
    "created",
    "model",
    "choices"
  ],
  "additionalProperties": {}
}