---
title: GPT OSS 120b — Open Reasoning LLM | ModelsLab
description: Access GPT OSS 120b model via API for high-reasoning tasks on single H100 GPU. Try agentic workflows and MoE efficiency now.
url: https://modelslab.com/gpt-oss-120b
canonical: https://modelslab.com/gpt-oss-120b
type: website
component: Seo/ModelPage
generated_at: 2026-04-24T23:29:27.085743Z
---

Available now on ModelsLab · Language Model

GPT OSS 120b
GPT OSS 120b Reasoning Power
---

[Try GPT OSS 120b](/models/openai/gpt-oss-120b) [API Documentation](https://docs.modelslab.com)

![GPT OSS 120b](https://assets.modelslab.ai/generations/32ccebf4-aaac-46b2-af6a-b19d11fcf8fa.webp)

Deploy GPT OSS 120b Efficiently
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MoE Architecture

### 117B Parameters Active 5.1B

Runs production reasoning on single H100 GPU with 128 experts.

Agentic Tasks

### Tool Use Native

Supports function calling, browsing, and code execution in 128K context.

Fine-Tuning Ready

### Customize Single Node

Fine-tune GPT OSS 120b model on one H100 for specialized cases.

Examples

See what GPT OSS 120b can create
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Copy any prompt below and try it yourself in the [playground](/models/openai/gpt-oss-120b).

Code Debug

“Debug this Python function for sorting algorithms. Identify efficiency issues and provide optimized version with explanations: def merge\_sort(arr): ...”

Math Proof

“Prove Fermat's Little Theorem step-by-step using modular arithmetic. Explain each inference clearly for advanced undergrad level.”

Physics Sim

“Simulate quantum entanglement in Bell's inequality experiment. Derive math, predict outcomes, and discuss EPR paradox implications.”

Architecture Design

“Design scalable microservices for e-commerce backend. Specify API endpoints, database schema, and deployment on Kubernetes.”

For Developers

A few lines of code.
GPT OSS 120b. One API call.
---

ModelsLab handles the infrastructure: fast inference, auto-scaling, and a developer-friendly API. No GPU management needed.

- **Serverless:** scales to zero, scales to millions
- **Pay per token,** no minimums
- **Python and JavaScript SDKs,** plus REST API

[API Documentation ](https://docs.modelslab.com)

PythonJavaScriptcURL

Copy

```
<code>import requests

response = requests.post(
    "https://modelslab.com/api/v7/llm/chat/completions",
    json={
  "key": "YOUR_API_KEY",
  "prompt": "",
  "model_id": ""
}
)
print(response.json())</code>
```

FAQ

Common questions about GPT OSS 120b
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[Read the docs ](https://docs.modelslab.com)

### What is GPT OSS 120b API?

GPT OSS 120b API provides access to the 117B MoE model for reasoning tasks. It fits single H100 GPU with 128K context. Deploy via endpoints like ours.

### Is GPT OSS 120b alternative to closed models?

GPT OSS 120b alternative matches o3 on benchmarks with open weights. Use for on-premises security. Fine-tune freely under Apache 2.0.

### GPT OSS 120b LLM specs?

117B total parameters, 5.1B active per token in MoE setup. Text-only with SwiGLU and 128 experts. 131K max output tokens.

### Can I fine-tune gpt oss 120b model?

Fine-tune gpt oss 120b model on single H100 node. Supports parameter-efficient methods. Ideal for custom agentic use cases.

### What hardware for gpt oss 120b api?

gpt oss 120b api runs on 80GB GPUs like H100 or MI300X. Activates 5.1B parameters per token. No multi-GPU needed for inference.

### GPT OSS 120b vs gpt-oss-20b?

GPT OSS 120b handles production high-reasoning; 20b suits low-latency edge. Both MoE with tool use. 120b nears o3 parity.

Ready to create?
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Start generating with GPT OSS 120b on ModelsLab.

[Try GPT OSS 120b](/models/openai/gpt-oss-120b) [API Documentation](https://docs.modelslab.com)

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*This markdown version is optimized for AI agents and LLMs.*

**Links:**
- [Website](https://modelslab.com)
- [API Documentation](https://docs.modelslab.com)
- [Blog](https://modelslab.com/blog)

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*Generated by ModelsLab - 2026-04-25*