GPT-5.3 Chat (GPT 5.3 Instant) is now available on AI Gateway. This update focuses on tone, relevance, and conversational flow for more accurate answers, better-contextualized web results, and fewer unnecessary refusals and caveats. It also reduces hallucination rates and produces smoother and more direct responses. To use this model, set model to in the AI SDK.openai/gpt-5.3-chat AI Gateway provides a unified API for calling models, tracking usage and cost, and configuring retries, failover, and performance optimizations for higher-than-provider uptime.

It includes built-in , support, and intelligent provider routing with automatic retries.observabilityBring Your Own Key Learn more about , view the or try it in our .AI GatewayAI Gateway model leaderboardmodel playground Read more