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gpt-oss-20b

Text Generation • OpenAI
@cf/openai/gpt-oss-20b

OpenAI’s open-weight models designed for powerful reasoning, agentic tasks, and versatile developer use cases – gpt-oss-20b is for lower latency, and local or specialized use-cases.

Model Info
Context Window ↗128,000 tokens
Unit Pricing$0.20 per M input tokens, $0.30 per M output tokens

Usage

Worker

 
export default {
  async fetch(request, env): Promise<Response> {
    const response = await env.AI.run('@cf/openai/gpt-oss-20b', {
      instructions: 'You are a concise.',
      input: 'What is the origin of the phrase Hello, World?',
    });


    return Response.json(response);
  },
} satisfies ExportedHandler<Env>;

Python

 
import os
import 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-20b",
      "input": "Tell me all about PEP-8"
    }
)
result = response.json()
print(result)

curl
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-20b",
    "input": "What are the benefits of open-source models?"
  }'

Parameters

* indicates a required field

Input

  • input required

    • 0 string

      Responses API Input messages. Refer to OpenAI Responses API docs to learn more about supported content types

    • 1 array

      Responses API Input messages. Refer to OpenAI Responses API docs to learn more about supported content types

  • reasoning object

    • effort string

      Constrains effort on reasoning for reasoning models. Currently supported values are low, medium, and high. Reducing reasoning effort can result in faster responses and fewer tokens used on reasoning in a response.

    • summary string

      A summary of the reasoning performed by the model. This can be useful for debugging and understanding the model's reasoning process. One of auto, concise, or detailed.

Output

  • 0 object

  • 1 string

API Schemas

The following schemas are based on JSON Schema

{
    "type": "object",
    "title": "GPT_OSS_Responses",
    "properties": {
        "input": {
            "anyOf": [
                {
                    "type": "string"
                },
                {
                    "items": {},
                    "type": "array"
                }
            ],
            "description": "Responses API Input messages. Refer to OpenAI Responses API docs to learn more about supported content types",
            "title": "Input"
        },
        "reasoning": {
            "type": "object",
            "properties": {
                "effort": {
                    "type": "string",
                    "description": "Constrains effort on reasoning for reasoning models. Currently supported values are low, medium, and high. Reducing reasoning effort can result in faster responses and fewer tokens used on reasoning in a response.",
                    "enum": [
                        "low",
                        "medium",
                        "high"
                    ]
                },
                "summary": {
                    "type": "string",
                    "description": "A summary of the reasoning performed by the model. This can be useful for debugging and understanding the model's reasoning process. One of auto, concise, or detailed.",
                    "enum": [
                        "auto",
                        "concise",
                        "detailed"
                    ]
                }
            }
        }
    },
    "required": [
        "input"
    ]
}