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GPT-5.1-Codex

OpenAIProprietaryPending Human Review

GPT-5.1-Codex is the GPT-5.1 coding specialization for Codex and comparable tool-based development environments. It combines reasoning, image understanding, and text generation for implementation and repository work, with Responses API access. It is a distinct coding model identity; the Codex application and its underlying harness are separate products.

2025-11-13
Unreleased
Undisclosed proprietary architecture
Proprietary

Specifications

Parameters
Unreleased
Architecture
Undisclosed proprietary architecture
License
Proprietary
Context Window
400,000 tokens
Max Output
128,000 tokens
Training Data Cutoff
Sep 30, 2024
Type
multimodal
Modalities
textimage

Benchmark Scores

Advanced Specifications

Model Family
GPT-5
API Access
Not Available
Chat Interface
Not Available
Variants
gpt-5.1-codex

Capabilities & Limitations

Capabilities
agentic codingcode reviewdebuggingvisiontool use
Known Limitations
Can produce incorrect factual claims or code; important results require independent verification.This API identity was retired on July 23, 2026; preserved for historical coverage.
Notable Use Cases
coding assistantsrepository changessoftware testing
Function Calling Support
Yes
Tool Use Support
Yes

Related Models