Back to Blog
4 min
By OpenHunts Editorial Team
OpenAIOpen SourceAI ModelsFree DeploymentMachine LearningTutorialCloud ComputingAI Development

Deploy OpenAI's Open Source Model for Free — Tutorial

Complete step-by-step guide to deploy OpenAI's open source models for free. Learn how to set up, configure, and run AI models without spending a dime using free cloud platforms.

Deploy OpenAI Models

Deploy OpenAI's Open Source Model for Free — Using Hugging Face

1. Meet gpt-oss-120b ✨

  • On August 6, 2025, OpenAI released gpt-oss-120b and gpt-oss-20b.
  • gpt-oss-120b performs as well or even better than OpenAI’s o4-mini on reasoning benchmarks. gpt-oss-20b is close to o3-mini.
  • Both models are fully open source under the Apache 2.0 license, meaning you can use them for commercial or local deployments.
  • Official model repo on Hugging Face: openai/gpt-oss-120b

2. Why Deploy It Yourself?

  • Save money: No need to pay for OpenAI API calls — run it for free.
  • More control: Customize output, reasoning depth, logic, etc.
  • Better privacy: Run it locally or on your own server.
  • Fully open: Great for fine-tuning, prompt testing, and agent workflows.

3. What You Need

  • A free Hugging Face account
  • Choose a model: openai/gpt-oss-120b or openai/gpt-oss-20b

4. Option 1: Use Hugging Face Inference Endpoints

Hugging Face offers an official GPT-OSS Inference API with OpenAI-compatible interface.

Steps:

  1. Go to the model page: openai/gpt-oss-120b
  2. Click “Deploy → Inference Endpoint”
  3. Choose a free CPU/GPU option (limits apply)
  4. Use the code below to try it:
  • Supports function calling, JSON output, and reasoning control
  • Free tier is limited — great for testing. Upgrade to PRO for more usage.

5. Option 2: Deploy a Chat UI with Hugging Face Spaces

Want to build a web-based chatbot you can share? Use Hugging Face Spaces + a Gradio template:

Steps:

  1. Create a new Space using the Gradio (Python) option
  2. Use a template like huggingface-projects/llm-chatbot
  3. Replace the model with openai/gpt-oss-120b
  4. Edit app.py to support harmony format or JSON replies
  5. Once deployed, you’ll get a shareable chatbot URL

6. Option 3: Run gpt-oss-20b Locally (Recommended) 🖥️

gpt-oss-20b is smaller but still powerful — much easier to run on local machines.

a. Use Ollama (Great for Mac)

ollama pull gpt-oss:20b
ollama run gpt-oss:20b
  • Recommended: 24GB+ GPU or Mac M2 Ultra / M3 Max
  • Offline, fast, great for local testing or fine-tuning

b. Run an OpenAI-Compatible API with vLLM

pip install vllm
python3 -m vllm.entrypoints.openai.api_server --model openai/gpt-oss-20b

c. Use Hugging Face Transformers

from transformers import AutoTokenizer, AutoModelForCausalLM

model_id = "openai/gpt-oss-20b"
tokenizer = AutoTokenizer.from_pretrained(model_id)
model = AutoModelForCausalLM.from_pretrained(model_id, device_map="auto")

prompt = "Explain the difference between TCP and UDP."
inputs = tokenizer(prompt, return_tensors="pt").to(model.device)
outputs = model.generate(**inputs, max_new_tokens=100)
print(tokenizer.decode(outputs[0], skip_special_tokens=True))

7. Notes & Limitations ⚠️

  • gpt-oss-120b requires very large GPUs (A100 / H100). Not practical for most local setups.
  • Free endpoints have cold starts and delays — better for light testing.
  • OSS models are still new — use harmony templates for clean output.
  • For production, always check the Apache 2.0 license and data responsibilities.

8. Final Thoughts ✅

OpenAI's GPT-OSS release marks its first truly open, top-tier language models.
You can deploy them for free using Hugging Face — perfect for chat UIs, prompt testing, agents, or product demos.
gpt-oss-20b works well on local machines, while 120b is best for hosted use.
Try it today — and say goodbye to API bills!

Resources and Links

Official Models:

Deployment Platforms:

Local Deployment Tools:

Documentation:

Have questions or need help with your deployment? Join our community on Discord or reach out to our team. We're here to help you succeed with open source AI.

Share this article
Deploy OpenAI's Open Source Model for Free — Tutorial | OpenHunts