GPT-5.5 and GPT-5.5 Pro are live on AI Gateway. Built for long-running agentic work and more token-efficient than GPT-5.4. Use 𝚖𝚘𝚍𝚎𝚕: '𝚘𝚙𝚎𝚗𝚊𝚒/𝚐𝚙𝚝-𝟻.𝟻' or '𝚘𝚙𝚎𝚗𝚊𝚒/𝚐𝚙𝚝-𝟻.𝟻-𝚙𝚛𝚘' to get started. https://vercel.com/changelog/gpt-5.5-on-ai-gateway