# Source: https://developers.openai.com/changelog/codex/2025-12-18.md

# Introducing GPT-5.2-Codex

- Date: 2025-12-18
- Products: Codex

[Today we are releasing GPT-5.2-Codex](http://www.openai.com/index/gpt-5-2-codex), the most advanced agentic coding model yet for complex, real-world software engineering.

GPT-5.2-Codex is a version of [GPT-5.2](https://openai.com/index/introducing-gpt-5-2/) further optimized for agentic coding in Codex, including improvements on long-horizon work through context compaction, stronger performance on large code changes like refactors and migrations, improved performance in Windows environments, and significantly stronger cybersecurity capabilities.

Starting today, the CLI and IDE Extension will default to `gpt-5.2-codex` for users who are signed in with ChatGPT. API access for the model will come soon.

If you have a model specified in your [`config.toml` configuration file](https://developers.openai.com/codex/local-config), you can instead try out `gpt-5.2-codex` for a new Codex CLI session using:

```bash
codex --model gpt-5.2-codex
```

You can also use the `/model` slash command in the CLI. In the Codex IDE Extension you can select GPT-5.2-Codex from the dropdown menu.

If you want to switch for all sessions, you can change your default model to `gpt-5.2-codex` by updating your `config.toml` [configuration file](https://developers.openai.com/codex/local-config):

```toml
model = "gpt-5.2-codex”
```