Model
Inference & Serving
gpt-oss
1OpenAI 2open 3weight 4reasoning 5model 6release
the six Ws · specification
W1
Who
Released by OpenAI as its first open weight model family since GPT-2.
W2
What
gpt-oss is a pair of open weight reasoning models, 120b and 20b, built for strong reasoning and agentic performance.
W3
Where
Weights and code are hosted on GitHub at openai/gpt-oss and on the Hugging Face Hub.
W4
When
Released in August 2025.
W5
Why
It gives developers a locally runnable, permissively licensed alternative to OpenAI's closed API models for reasoning heavy workloads.
W6
With
Uses a mixture of experts architecture and runs via Transformers, vLLM, Ollama or llama.cpp.
W7
Watch
Apache 2.0 licensed, open weights, released and maintained by OpenAI, roughly 20k GitHub stars.
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