OpenAI launches GPT-5.4 mini and GPT-5.4 nano on APIs
TestingCatalog - TestingCatalog - New and unreleased AI feature…
March 18, 2026
OpenAI introduces GPT-5.4 mini for faster, cost-efficient coding copilots, automation, and agent systems, now available in API, Codex, and ChatGPT. GPT-5.4 nano is now available via the API as well.
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