GPT-5.1 Codex Max
GPT-5.1 Codex Max is the most capable Codex variant in the GPT-5.1 family, with a 272,000-token context window built for demanding, long-horizon development work. It targets large-scale code generation, complex refactoring, cross-file consistency, and detailed debugging. Designed for teams tackling architecture decisions, multi-service integrations, and extended coding projects, it supports function calling and structured outputs so it can drive automated code workflows across a full codebase.
Key info
Input
Output
Features
Context window
272K
Max output
128K
Available routes
No routes currently available — GPT-5.1 Codex Max isn't routed through the Opper gateway right now. It may return.
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