# GPT 5.1 Codex Max now available on Vercel AI Gateway

By Steven Van · 2025-12-05

OpenAI's GPT-5.1 Codex Max joins Vercel AI Gateway, usable via the AI SDK by setting the model to openai/gpt-5.1-codex-max.

Vercel's [AI Gateway](<https://creatorstoolbox.com/tools/vercel>) now supports OpenAI's GPT-5.1 Codex Max, giving access to the model without a separate OpenAI account. The model uses a training process called compaction to work across multiple context windows on real-world software engineering tasks, and Vercel says it is faster and more token efficient than previous Codex models, built for long-running coding tasks that keep context without starting new sessions. To use it with the AI SDK, set the model to openai/gpt-5.1-codex-max.

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[Original source](<https://vercel.com/docs/ai-gateway>)

[Read GPT 5.1 Codex Max now available on Vercel AI Gateway on Creators Toolbox](<https://creatorstoolbox.com/blog/vercel-gpt-5-1-codex-max-now-available-on-vercel-ai-gateway>)

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Canonical source: https://creatorstoolbox.com/blog/vercel-gpt-5-1-codex-max-now-available-on-vercel-ai-gateway