--- title: GPT-5.5 description: GPT-5.5 is OpenAI's flagship model with strong coding, reasoning, and multimodal capabilities. image: https://developers.cloudflare.com/dev-products-preview.png --- [Skip to content](#%5Ftop) ![OpenAI logo](https://developers.cloudflare.com/_astro/openai.BI8PEEzI.svg) # GPT-5.5 Text Generation • OpenAI • Proxied `openai/gpt-5.5` GPT-5.5 is OpenAI's flagship model with strong coding, reasoning, and multimodal capabilities. | Model Info | | | -------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------- | | Context Window[ ↗](https://developers.cloudflare.com/workers-ai/glossary/) | 1,000,000 tokens | | Terms and License | [link ↗](https://openai.com/policies/) | | More information | [link ↗](https://openai.com/) | | Pricing | [View pricing in the Cloudflare dashboard ↗](https://dash.cloudflare.com/?to=/:account/ai/models/openai/gpt-5.5) | ## Usage TypeScript ``` 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) ``` Explain Code Input / Output JSON * [ Input ](#tab-panel-366) * [ Output ](#tab-panel-367) ``` { "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 ](#tab-panel-370) * [ Output ](#tab-panel-371) ▶messages\[\] `array`required temperature `number`minimum: 0maximum: 2 max\_tokens `number`exclusiveMinimum: 0 max\_completion\_tokens `number`exclusiveMinimum: 0 top\_p `number`minimum: 0maximum: 1 frequency\_penalty `number`minimum: \-2maximum: 2 presence\_penalty `number`minimum: \-2maximum: 2 stream `boolean` ▶stream\_options{} `object` ▶tools\[\] `array` tool\_choice `` response\_format `` id `string` object `string` created `number` model `string` ▶choices\[\] `array` ▶usage{} `object` ## API Schemas * [ Input ](#tab-panel-368) * [ Output ](#tab-panel-369) ``` { "$schema": "https://json-schema.org/draft/2020-12/schema", "type": "object", "properties": { "messages": { "type": "array", "items": { "type": "object", "properties": { "role": { "type": "string", "enum": [ "system", "developer", "user", "assistant", "tool" ] }, "content": { "anyOf": [ { "type": "string" }, { "type": "null" }, { "type": "array", "items": {} } ] } }, "required": [ "role", "content" ], "additionalProperties": {} } }, "temperature": { "type": "number", "minimum": 0, "maximum": 2 }, "max_tokens": { "type": "number", "exclusiveMinimum": 0 }, "max_completion_tokens": { "type": "number", "exclusiveMinimum": 0 }, "top_p": { "type": "number", "minimum": 0, "maximum": 1 }, "frequency_penalty": { "type": "number", "minimum": -2, "maximum": 2 }, "presence_penalty": { "type": "number", "minimum": -2, "maximum": 2 }, "stream": { "type": "boolean" }, "stream_options": { "type": "object", "properties": { "include_usage": { "type": "boolean" } }, "additionalProperties": false }, "tools": { "type": "array", "items": {} }, "tool_choice": {}, "response_format": {} }, "required": [ "messages" ], "additionalProperties": {} } ``` Explain Code ``` { "$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": {} } ``` Explain Code ```json {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/directory/","name":"Directory"}},{"@type":"ListItem","position":2,"item":{"@id":"/ai/","name":"AI"}},{"@type":"ListItem","position":3,"item":{"@id":"/ai/models/","name":"Models"}}]} ```