GPT-5.2-Codex Released: Agentic Coding Model

TL;DR

• GPT-5.2-Codex is now the default model for Codex CLI and IDE Extension
• Optimized for long-horizon work, large refactors, Windows environments, and security
• API access coming soon; CLI users can opt-in now

New

• GPT-5.2-Codex model — Advanced agentic coding model with context compaction for sustained multi-step work and stronger performance on large-scale refactors and migrations.
• Windows environment improvements — Better performance and compatibility in Windows development workflows.
• Enhanced cybersecurity capabilities — Significantly stronger security-aware code generation and vulnerability detection.

Changed

• Default model for CLI and IDE Extension — Users signed in with ChatGPT now default to gpt-5.2-codex instead of previous versions.

To use GPT-5.2-Codex in your current session, run:

codex --model gpt-5.2-codex

Or update your config.toml to make it permanent:

model = "gpt-5.2-codex"

You can also switch models via the /model slash command in the CLI or the dropdown menu in the IDE Extension.

API access for GPT-5.2-Codex is coming soon. Check availability updates here.

Source: Codex