GPT-5.1 Codex
GPT-5.1 Codex from OpenAI — text model on the Opper gateway.
ToolsStructured output
Context window
272K
Max output
128K
Input price
$1.25 /1M
Output price
$10.00 /1M
Benchmarks
Independent benchmark scores — composite indices for reasoning, coding, and math, plus individual eval scores where available.
Intelligence Index43.1
Coding Index36.6
Math Index95.7
MMLU-Pro
86%
GPQA Diamond
86%
Humanity's Last Exam
23%
LiveCodeBench
85%
SciCode
40%
AIME 2025
96%
IFBench
70%
Long-context reasoning
67%
Terminal-Bench Hard
35%
τ²-Bench Telecom
83%
See full leaderboard →Benchmarks via Artificial Analysis · View on AA
Available routes
The same GPT-5.1 Codex runs on 1 route through the Opper gateway. Each route has its own data-handling posture.
| Provider | Region | Zero data retention | Training | Logging | Contract | Input | Output |
|---|---|---|---|---|---|---|---|
| OpenAI | US | Opt-in | No (opt-in) | Up to 30 days for abuse monitoring on stateless endpoints. Stateful endpoints (Conversations, ChatKit, Vector Stores) retain until deleted. | Enterprise | $1.25 | $10.00 |
Human review: Abuse-flagged only