On October 29, 2025, OpenAI made a significant move by launching two brand - new open - source safe reasoning models, namely gpt - oss - safeguard - 120b and gpt - oss - safeguard - 20b, both licensed under the Apache 2.0 framework. These models are characterized by their remarkable ability to strictly follow instructions, effectively utilize tools, and demonstrate robust reasoning skills. Moreover, they offer the flexibility for customized modifications and generate a full chain - of - thought output.
