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GPT 5.1 Codex Max

GPT 5.1 Codex Max applies maximum compute to the GPT-5.1 codex architecture, delivering the deepest reasoning and most thorough code analysis available in OpenAI's coding agent lineup for the most demanding software engineering tasks.

ReasoningFile InputTool UseVision (Image)Web SearchImplicit Caching
index.ts
import { streamText } from 'ai'
const result = streamText({
model: 'openai/gpt-5.1-codex-max',
prompt: 'Why is the sky blue?'
})
Latency

P50 time to first token (TTFT) on live AI Gateway traffic, in milliseconds. View the docs for more info.