--- title: gpt-oss-120b description: OpenAI's open-weight models designed for powerful reasoning, agentic tasks, and versatile developer use cases – gpt-oss-120b is for production, general purpose, high reasoning use-cases. image: https://developers.cloudflare.com/dev-products-preview.png --- > Documentation Index > Fetch the complete documentation index at: https://developers.cloudflare.com/workers-ai/llms.txt > Use this file to discover all available pages before exploring further. [Skip to content](#%5Ftop) ![OpenAI logo](https://developers.cloudflare.com/_astro/openai.BI8PEEzI.svg) # gpt-oss-120b Text Generation • OpenAI `@cf/openai/gpt-oss-120b` OpenAI's open-weight models designed for powerful reasoning, agentic tasks, and versatile developer use cases – gpt-oss-120b is for production, general purpose, high reasoning use-cases. | Model Info | | | ------------------------------------------------------------------------------------ | --------------------------------------------------- | | Context Window[ ↗](https://developers.cloudflare.com/workers-ai/glossary/) | 128,000 tokens | | Function calling [ ↗](https://developers.cloudflare.com/workers-ai/function-calling) | Yes | | Reasoning | Yes | | Unit Pricing | $0.35 per M input tokens, $0.75 per M output tokens | ## Usage * [ TypeScript ](#tab-panel-5061) * [ Python ](#tab-panel-5062) * [ curl ](#tab-panel-5063) ``` export default { async fetch(request, env): Promise { const response = await env.AI.run('@cf/openai/gpt-oss-120b', { instructions: 'You are a concise assistant.', input: 'What is the origin of the phrase Hello, World?', }); return Response.json(response); },} satisfies ExportedHandler; ``` ``` import osimport requests ACCOUNT_ID = os.environ.get("CLOUDFLARE_ACCOUNT_ID")AUTH_TOKEN = os.environ.get("CLOUDFLARE_AUTH_TOKEN") prompt = "Tell me all about PEP-8"response = requests.post( f"https://api.cloudflare.com/client/v4/accounts/{ACCOUNT_ID}/ai/v1/responses", headers={"Authorization": f"Bearer {AUTH_TOKEN}"}, json={ "model": "@cf/openai/gpt-oss-120b", "input": "Tell me all about PEP-8" })result = response.json()print(result) ``` Terminal window ``` curl https://api.cloudflare.com/client/v4/accounts/$CLOUDFLARE_ACCOUNT_ID/ai/v1/responses -H "Content-Type: application/json" -H "Authorization: Bearer $CLOUDFLARE_AUTH_TOKEN" -d '{ "model": "@cf/openai/gpt-oss-120b", "input": "What are the benefits of open-source models?" }' ``` Multiple API format support This model supports three different API formats: * **Responses API** (`/ai/v1/responses`) - Native OpenAI responses format shown above with `input` parameter * **Workers AI Run** (`/ai/run`) - Dynamic format detection, accepts Chat Completions (`messages`), legacy Completions (`prompt`), or Responses API (`input`) * **Chat Completions** (`/v1/chat/completions`) - OpenAI-compatible endpoint with `messages` array. Refer to [OpenAI Compatibility ](https://developers.cloudflare.com/workers-ai/configuration/open-ai-compatibility/) for details. ## Parameters Synchronous — Send a request and receive a complete response * [ Input ](#tab-panel-5064) * [ Output ](#tab-panel-5065) Input format Prompt Simple text input for single-turn interactions Messages Structured conversation format with roles (user, assistant, system) prompt `string`requiredminLength: 1The input text prompt for the model to generate a response. lora `string`Name of the LoRA (Low-Rank Adaptation) model to fine-tune the base model. ▶response\_format{} `object` raw `boolean`default: falseIf true, a chat template is not applied and you must adhere to the specific model's expected formatting. stream `boolean`default: falseIf true, the response will be streamed back incrementally using SSE, Server Sent Events. max\_tokens `integer`default: 256The maximum number of tokens to generate in the response. temperature `number`default: 0.6minimum: 0maximum: 5Controls the randomness of the output; higher values produce more random results. top\_p `number`minimum: 0.001maximum: 1Adjusts the creativity of the AI's responses by controlling how many possible words it considers. Lower values make outputs more predictable; higher values allow for more varied and creative responses. top\_k `integer`minimum: 1maximum: 50Limits the AI to choose from the top 'k' most probable words. Lower values make responses more focused; higher values introduce more variety and potential surprises. seed `integer`minimum: 1maximum: 9999999999Random seed for reproducibility of the generation. repetition\_penalty `number`minimum: 0maximum: 2Penalty for repeated tokens; higher values discourage repetition. frequency\_penalty `number`minimum: \-2maximum: 2Decreases the likelihood of the model repeating the same lines verbatim. presence\_penalty `number`minimum: \-2maximum: 2Increases the likelihood of the model introducing new topics. response `string`The generated text response from the model ▶usage{} `object`Usage statistics for the inference request ▶tool\_calls\[\] `array`An array of tool calls requests made during the response generation Streaming — Send a request with \`stream: true\` and receive server-sent events * [ Input ](#tab-panel-5066) * [ Output ](#tab-panel-5067) Input format Prompt Simple text input for single-turn interactions Messages Structured conversation format with roles (user, assistant, system) prompt `string`requiredminLength: 1The input text prompt for the model to generate a response. lora `string`Name of the LoRA (Low-Rank Adaptation) model to fine-tune the base model. ▶response\_format{} `object` raw `boolean`default: falseIf true, a chat template is not applied and you must adhere to the specific model's expected formatting. stream `boolean`default: falseIf true, the response will be streamed back incrementally using SSE, Server Sent Events. max\_tokens `integer`default: 256The maximum number of tokens to generate in the response. temperature `number`default: 0.6minimum: 0maximum: 5Controls the randomness of the output; higher values produce more random results. top\_p `number`minimum: 0.001maximum: 1Adjusts the creativity of the AI's responses by controlling how many possible words it considers. Lower values make outputs more predictable; higher values allow for more varied and creative responses. top\_k `integer`minimum: 1maximum: 50Limits the AI to choose from the top 'k' most probable words. Lower values make responses more focused; higher values introduce more variety and potential surprises. seed `integer`minimum: 1maximum: 9999999999Random seed for reproducibility of the generation. repetition\_penalty `number`minimum: 0maximum: 2Penalty for repeated tokens; higher values discourage repetition. frequency\_penalty `number`minimum: \-2maximum: 2Decreases the likelihood of the model repeating the same lines verbatim. presence\_penalty `number`minimum: \-2maximum: 2Increases the likelihood of the model introducing new topics. type `string` title `Stream_Output` description `Server-Sent Events stream when streaming is enabled` contentType `text/event-stream` format `binary` Batch — Send multiple requests in a single API call * [ Input ](#tab-panel-5068) * [ Output ](#tab-panel-5069) ▶requests\[\] `array`required response `string`The generated text response from the model ▶usage{} `object`Usage statistics for the inference request ▶tool\_calls\[\] `array`An array of tool calls requests made during the response generation ## API Schemas (Raw) Synchronous Input [ ](https://developers.cloudflare.com/workers-ai/models/gpt-oss-120b/sync-input.json "Open") [ ](https://developers.cloudflare.com/workers-ai/models/gpt-oss-120b/sync-input.json "Download") Synchronous Output [ ](https://developers.cloudflare.com/workers-ai/models/gpt-oss-120b/sync-output.json "Open") [ ](https://developers.cloudflare.com/workers-ai/models/gpt-oss-120b/sync-output.json "Download") Streaming Input [ ](https://developers.cloudflare.com/workers-ai/models/gpt-oss-120b/streaming-input.json "Open") [ ](https://developers.cloudflare.com/workers-ai/models/gpt-oss-120b/streaming-input.json "Download") Streaming Output [ ](https://developers.cloudflare.com/workers-ai/models/gpt-oss-120b/streaming-output.json "Open") [ ](https://developers.cloudflare.com/workers-ai/models/gpt-oss-120b/streaming-output.json "Download") Batch Input [ ](https://developers.cloudflare.com/workers-ai/models/gpt-oss-120b/batch-input.json "Open") [ ](https://developers.cloudflare.com/workers-ai/models/gpt-oss-120b/batch-input.json "Download") Batch Output [ ](https://developers.cloudflare.com/workers-ai/models/gpt-oss-120b/batch-output.json "Open") [ ](https://developers.cloudflare.com/workers-ai/models/gpt-oss-120b/batch-output.json "Download") ```json {"@context":"https://schema.org","@type":"TechArticle","@id":"https://developers.cloudflare.com/workers-ai/models/gpt-oss-120b/#page","headline":"gpt-oss-120b (OpenAI) · Cloudflare AI docs · Cloudflare Workers AI docs","description":"OpenAI's open-weight models designed for powerful reasoning, agentic tasks, and versatile developer use cases – gpt-oss-120b is for production, general purpose, high reasoning use-cases.","url":"https://developers.cloudflare.com/workers-ai/models/gpt-oss-120b/","inLanguage":"en","image":"https://developers.cloudflare.com/dev-products-preview.png","publisher":{"@type":"Organization","name":"Cloudflare","url":"https://www.cloudflare.com/"},"isPartOf":{"@type":"WebSite","@id":"https://developers.cloudflare.com/#website","name":"Cloudflare Docs","url":"https://developers.cloudflare.com/"}} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/directory/","name":"Directory"}},{"@type":"ListItem","position":2,"item":{"@id":"/workers-ai/","name":"Workers AI"}},{"@type":"ListItem","position":3,"item":{"@id":"/workers-ai/models/","name":"Models"}}]} ```