GPT-5.4 and GPT-5.4 Pro are now available on AI Gateway. This model brings the agentic and reasoning leaps from GPT-5.3-Codex to all domains. This includes knowledge work like reports, spreadsheets, presentations, and analysis in addition to coding. It handles complex multi-step workflows more reliably, including tasks that involve tools, research, and pulling from multiple sources. GPT-5.4 is faster and also more token-efficient than previous iterations (GPT-5.2). GPT-5.4 Pro is for developers who need maximum performance on the most complex tasks. To use this model, set model to openai/gpt-5.4 or openai/gpt-5.4-pro in the AI SDK. import { streamText } from 'ai' ; const result = streamText ( { model : 'openai/gpt-5.4' , prompt : ` Refactor our API layer to use the new auth SDK, update the affected tests and docs, then generate a migration guide for the rest of the team.…