How to set up and run OpenAI’s ‘gpt-oss-20b’ open weight model locally on your Mac

This week, OpenAI released its long-awaited open weight model called gpt-oss. Part of the appeal of gpt-oss is that you can run it locally on your own hardware, including Macs with Apple silicon. Here’s how to get started and what to expect.

Models and Macs

First, gpt-oss comes in two flavors: gpt-oss-20b and gpt-oss-120b. The former is described as a medium open weight model, while the latter is considered a heavy open weight model.

The medium model is what Apple silicon Macs…