ChatGPT Learn Docs
Configuration
Set defaults, add durable context, and customize how ChatGPT and Codex developer tools work.
Explore customization
Configuration shapes how ChatGPT and Codex developer tools behave across chats, repositories, and machines. Durable context, config files, repository guidance, subagents, external connections, and Linux and Windows setup work together to keep those workflows consistent for individuals and teams.
Customization
Adapt the experience and carry useful context between chats.
Config file
Control models, tools, environments, and defaults with configuration files and variables.
- Config basics Understand configuration layers and create a config file.
- Advanced config Use profiles, providers, policies, and advanced options.
- Config reference Look up every supported configuration key.
- Environment variables Set values that change across systems and sessions.
- Sample config Start from a complete, annotated configuration example.