GPT-OSS 120B

OpenAI’s open-weight language model with 120 billion parameters for text generation. See model inputs and outputs on Runpod Public Endpoints.

GPT-OSS 120B is OpenAI’s open-weight 120B parameter language model, offering powerful text generation capabilities with advanced reasoning and instruction-following abilities.

Try in playground

Test GPT-OSS 120B in the Runpod Hub playground.

Endpoint	https://api.runpod.ai/v2/gpt-oss-120b/runsync
Pricing	$10.00 per 1M tokens
Type	Text generation

This endpoint is fully compatible with the OpenAI API. See the OpenAI compatibility examples below.

Request

All parameters are passed within the input object in the request body.

input.prompt · string · required

Prompt for text generation.

input.max_tokens · integer · default: "512"

Maximum number of tokens to output.

input.temperature · float · default: "0.7"

Randomness of the output. Lower values make output more predictable and deterministic. Range: 0.0-1.0.

input.top_p · float

Nucleus sampling threshold. Samples from the smallest set of words whose cumulative probability exceeds this threshold.

input.top_k · integer

Restricts sampling to the top K most probable words.

input.stop · string

Stops generation if the given string is encountered.

cURL

curl -X POST "https://api.runpod.ai/v2/gpt-oss-120b/runsync" \
  -H "Authorization: Bearer $RUNPOD_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "input": {
      "prompt": "Explain the concept of quantum entanglement in simple terms:",
      "max_tokens": 512,
      "temperature": 0.7
    }
  }'

Response

id · string

Unique identifier for the request.

status · string

Request status. Returns COMPLETED on success, FAILED on error.

delayTime · integer

Time in milliseconds the request spent in queue before processing began.

executionTime · integer

Time in milliseconds the model took to generate the response.

output · object

The generation result containing the text and usage information.

output.choices · array

Array containing the generated text.

output.cost · float

Cost of the generation in USD.

output.usage · object

Token usage information with input and output counts.

200

{
  "delayTime": 30,
  "executionTime": 4521,
  "id": "sync-a1b2c3d4-e5f6-7890-abcd-ef1234567890-u1",
  "output": [
    {
      "choices": [
        {
          "tokens": [
            "Quantum entanglement is a phenomenon where two particles become connected in such a way that measuring one particle instantly affects the other, no matter how far apart they are..."
          ]
        }
      ],
      "cost": 0.005,
      "usage": {
        "input": 15,
        "output": 485
      }
    }
  ],
  "status": "COMPLETED"
}

OpenAI API compatibility

GPT-OSS 120B is fully compatible with the OpenAI API format. You can use the OpenAI Python client to interact with this endpoint.

Python (OpenAI SDK)

from openai import OpenAI

client = OpenAI(
    api_key=RUNPOD_API_KEY,
    base_url="https://api.runpod.ai/v2/gpt-oss-120b/openai/v1",
)

response = client.chat.completions.create(
    model="gpt-oss-120b",
    messages=[
        {
            "role": "system",
            "content": "You are a helpful assistant.",
        },
        {
            "role": "user",
            "content": "Explain the concept of quantum entanglement in simple terms.",
        },
    ],
    max_tokens=512,
)

print(response.choices[0].message.content)

For streaming responses, add stream=True:

Python (Streaming)

response = client.chat.completions.create(
    model="gpt-oss-120b",
    messages=[
        {"role": "user", "content": "Write a short story about space exploration."}
    ],
    max_tokens=512,
    stream=True,
)

for chunk in response:
    if chunk.choices[0].delta.content:
        print(chunk.choices[0].delta.content, end="")

For more details, see Send vLLM requests and the OpenAI API compatibility guide.

Cost calculation

GPT-OSS 120B charges $10.00 per 1M tokens. Example costs:

Tokens	Cost
1,000 tokens	$0.01
10,000 tokens	$0.10
100,000 tokens	$1.00
1,000,000 tokens	$10.00