gpt-5.1-codex

Name: gpt-5.1-codex
Author: Azure AI Foundry

deprecatedproprietary

- Responses API only. - Text and image processing - Structured outputs. - Functions, tools, and parallel tool calling. - Full summary of capabilities - Optimized for Codex CLI & Codex VS Code extension

Intelligence

Reasoning

Speed

Context

400K

Max output

128K

Input price

$1.25/1M tokens

Output price

$10/1M tokens

Capabilities

Show unsupported (3)

Reasoning & Interaction

Reasoning

Tool Calling

Output Control

Structured Output

JSON Mode

Infrastructure

Streaming

Details

ProviderAzure AI Foundry

CreatorOpenAI

Familygpt-5.1

Licenseproprietary

Statusdeprecated

Typechat

Input modalitiestext, image

Output modalitiestext

Open weightNo

Parameters—

Architecture—

Context window400K tokens

Max input—

Max output128K tokens

Reasoning tokensYes

Knowledge cutoff2024-09-30

Release date—

Deprecation date2026-04-22

Sourceofficial

Tools

Function Callingfunction_calling

Call external functions and APIs

Pricing

Text tokensPer 1M tokens

	Input	Cached input	Output
Standard	$1.25	$0.125	$10

Family Comparison: gpt-5.1

Model	Caps	Perf	Speed	Context	Max out
gpt-5.1-chat Preview	RTJJMS	—	—	128K	16K
gpt-5.1-codex-max	RTJJMS	—	—	400K	128K
gpt-5.1-codex-mini	RTJJMS	—	—	400K	128K
gpt-5.1-codex	RTJJMS	—	—	400K	128K
GPT-5.1 series	RTJJMSB	—	—	400K	128K

API

GET/v1/models/azure/gpt-5.1-codex