You can now access OpenAI's latest Codex models, GPT-5.1 Codex Max with Vercel's and no other provider accounts required.AI Gateway Using a process called compaction, GPT-5.1 Codex Max has been trained to operate across multiple context windows and on real-world software engineering tasks. GPT-5.1 Codex Max is faster and more token efficient compared to previous Codex models, optimized for long-running coding tasks, and can maintain context and reasoning over long periods without needing to start new sessions.

To use GPT-5.1 Codex Max with the , set the model to .AI SDKopenai/gpt-5.1-codex-max 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 , , and intelligent with automatic retries.observabilityBring Your Own Key supportprovider routing Learn more about , view the or try it in our .AI GatewayAI Gateway model leaderboardmodel playground Read more