Model page
GPT OSS 20b
OpenAI's open-weight 21B MoE via Fireworks. Lower latency, local or specialized use-cases. 131k context. Does not support web search, image input, or function calling.
Key dates
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ChatGPT
GPT‑4o retirement (ChatGPT)
OpenAI is retiring GPT‑4o inside ChatGPT on February 13, 2026. This does not automatically imply API removal.