---
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.
title: gpt-oss-120b
image: https://developers.cloudflare.com/og-docs.png
---

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# gpt-oss-120b

Text Generation • OpenAI

Copy as Markdown| [View as Markdown](https://developers.cloudflare.com/ai/models/%40cf/openai/gpt-oss-120b/index.md)| [Agent setup](https://developers.cloudflare.com/agent-setup/)

`@cf/openai/gpt-oss-120b`

- Cloudflare-hosted
- Batch
- Function calling
- Reasoning

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/platform/glossary/) | 128,000 tokens |
| Function calling [↗](https://developers.cloudflare.com/workers-ai/function-calling/) | Yes |
| Reasoning | `low``medium` (default)`high` |
| Batch | Yes |
| Unit Pricing | $0.35 per M input tokens, $0.75 per M output tokens |

## Usage

```ts
export interface Env {
  AI: Ai;
}

export default {
  async fetch(request, env): Promise<Response> {

    const messages = [
      { role: "system", content: "You are a friendly assistant" },
      {
        role: "user",
        content: "What is the origin of the phrase Hello, World",
      },
    ];

    const stream = await env.AI.run("@cf/openai/gpt-oss-120b", {
      messages,
      stream: true,
    });

    return new Response(stream, {
      headers: { "content-type": "text/event-stream" },
    });
  },
} satisfies ExportedHandler<Env>;
```

```ts
export interface Env {
  AI: Ai;
}

export default {
  async fetch(request, env): Promise<Response> {

    const messages = [
      { role: "system", content: "You are a friendly assistant" },
      {
        role: "user",
        content: "What is the origin of the phrase Hello, World",
      },
    ];
    const response = await env.AI.run("@cf/openai/gpt-oss-120b", { messages });

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

```py
import os
import requests

ACCOUNT_ID = "your-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/run/@cf/openai/gpt-oss-120b",
    headers={"Authorization": f"Bearer {AUTH_TOKEN}"},
    json={
      "messages": [
        {"role": "system", "content": "You are a friendly assistant"},
        {"role": "user", "content": prompt}
      ]
    }
)
result = response.json()
print(result)
```

```sh
curl https://api.cloudflare.com/client/v4/accounts/$CLOUDFLARE_ACCOUNT_ID/ai/run/@cf/openai/gpt-oss-120b \
  -X POST \
  -H "Authorization: Bearer $CLOUDFLARE_AUTH_TOKEN" \
  -d '{ "messages": [{ "role": "system", "content": "You are a friendly assistant" }, { "role": "user", "content": "Why is pizza so good" }]}'
```

OpenAI compatible endpoints

Workers AI also supports OpenAI compatible API endpoints for `/v1/chat/completions` and `/v1/embeddings`. For more details, refer to [Configurations](https://developers.cloudflare.com/workers-ai/configuration/open-ai-compatibility/) .

## Parameters

<details>

<summary>Synchronous — Send a request and receive a complete response</summary>



Input format

Prompt Simple text input for single-turn interactionsMessages Structured conversation format with roles (user, assistant, system)

prompt

<code>string</code>requiredminLength: 1The input text prompt for the model to generate a response.

lora

<code>string</code>Name of the LoRA (Low-Rank Adaptation) model to fine-tune the base model.

▶response\_format{}

<code>object</code>

raw

<code>boolean</code>default: falseIf true, a chat template is not applied and you must adhere to the specific model's expected formatting.

stream

<code>boolean</code>default: falseIf true, the response will be streamed back incrementally using SSE, Server Sent Events.

max\_tokens

<code>integer</code>default: 256The maximum number of tokens to generate in the response.

temperature

<code>number</code>default: 0.6minimum: 0maximum: 5Controls the randomness of the output; higher values produce more random results.

top\_p

<code>number</code>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

<code>integer</code>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

<code>integer</code>minimum: 1maximum: 9999999999Random seed for reproducibility of the generation.

repetition\_penalty

<code>number</code>minimum: 0maximum: 2Penalty for repeated tokens; higher values discourage repetition.

frequency\_penalty

<code>number</code>minimum: -2maximum: 2Decreases the likelihood of the model repeating the same lines verbatim.

presence\_penalty

<code>number</code>minimum: -2maximum: 2Increases the likelihood of the model introducing new topics.

type

<code>object</code>

contentType

<code>application/json</code>

</details>

<details>

<summary>Streaming — Send a request with `stream: true` and receive server-sent events</summary>



Input format

Prompt Simple text input for single-turn interactionsMessages Structured conversation format with roles (user, assistant, system)

prompt

<code>string</code>requiredminLength: 1The input text prompt for the model to generate a response.

lora

<code>string</code>Name of the LoRA (Low-Rank Adaptation) model to fine-tune the base model.

▶response\_format{}

<code>object</code>

raw

<code>boolean</code>default: falseIf true, a chat template is not applied and you must adhere to the specific model's expected formatting.

stream

<code>boolean</code>default: falseIf true, the response will be streamed back incrementally using SSE, Server Sent Events.

max\_tokens

<code>integer</code>default: 256The maximum number of tokens to generate in the response.

temperature

<code>number</code>default: 0.6minimum: 0maximum: 5Controls the randomness of the output; higher values produce more random results.

top\_p

<code>number</code>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

<code>integer</code>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

<code>integer</code>minimum: 1maximum: 9999999999Random seed for reproducibility of the generation.

repetition\_penalty

<code>number</code>minimum: 0maximum: 2Penalty for repeated tokens; higher values discourage repetition.

frequency\_penalty

<code>number</code>minimum: -2maximum: 2Decreases the likelihood of the model repeating the same lines verbatim.

presence\_penalty

<code>number</code>minimum: -2maximum: 2Increases the likelihood of the model introducing new topics.

type

<code>string</code>

contentType

<code>text/event-stream</code>

format

<code>binary</code>

</details>

<details>

<summary>Batch — Send multiple requests in a single API call</summary>



▶requests\[]

<code>array</code>required

type

<code>object</code>

contentType

<code>application/json</code>

</details>

## API Schemas (Raw)

SynchronousInput [Open](https://developers.cloudflare.com/ai/models/@cf/openai/gpt-oss-120b/sync-input.json) [Download](https://developers.cloudflare.com/ai/models/@cf/openai/gpt-oss-120b/sync-input.json)

SynchronousOutput [Open](https://developers.cloudflare.com/ai/models/@cf/openai/gpt-oss-120b/sync-output.json) [Download](https://developers.cloudflare.com/ai/models/@cf/openai/gpt-oss-120b/sync-output.json)

StreamingInput [Open](https://developers.cloudflare.com/ai/models/@cf/openai/gpt-oss-120b/streaming-input.json) [Download](https://developers.cloudflare.com/ai/models/@cf/openai/gpt-oss-120b/streaming-input.json)

StreamingOutput [Open](https://developers.cloudflare.com/ai/models/@cf/openai/gpt-oss-120b/streaming-output.json) [Download](https://developers.cloudflare.com/ai/models/@cf/openai/gpt-oss-120b/streaming-output.json)

BatchInput [Open](https://developers.cloudflare.com/ai/models/@cf/openai/gpt-oss-120b/batch-input.json) [Download](https://developers.cloudflare.com/ai/models/@cf/openai/gpt-oss-120b/batch-input.json)

BatchOutput [Open](https://developers.cloudflare.com/ai/models/@cf/openai/gpt-oss-120b/batch-output.json) [Download](https://developers.cloudflare.com/ai/models/@cf/openai/gpt-oss-120b/batch-output.json)

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