The Engineering Value of Customizable Architecture
OpenAI Codex CLI innovatively adopts a three-layer management system of global configuration, project-level commands and personal preferences to realize intelligent adaptation of the development environment. The global configuration file (~/.codex/config.yaml) defines the default model selection (o4-mini, etc.) and error handling policies; the user instructions file (~/.codex/instructions.md) allows declaring technology stack preferences (e.g., mandatory use of Python 3.9); and the codex.md in the project root directory supports the team harmonization specifications (e.g., must pass lint checks before committing).
This hierarchical configuration is particularly well suited to enterprise development scenarios, such as code review rules that can be predefined in project-level directives or overriding approval modes via environment variables in the CI/CD process. The documentation display tool also supports temporary disabling of project-level configurations with the -no-project-doc parameter, providing flexibility for special cases. The deep integration of the configuration system with Git ensures consistency in the development environment as teams collaborate, an advantage that is difficult to achieve with traditional IDEs.
This answer comes from the articleOpenAI Codex CLI: Terminal Command Line AI Coding Assistant Released by OpenAIThe
