Codex
OpenAI's cloud coding agent that accepts a task description, works autonomously in a sandbox, and returns code changes with test results.
About
Codex is an autonomous coding agent from OpenAI that lets you delegate programming tasks in plain language. You describe what you want built or fixed, and Codex works in an isolated cloud environment for as long as the task requires, then returns a diff, logs, and test citations so you can review exactly what changed and why.
It integrates with GitHub for code review and connects to Slack for notifications. The agent runs on GPT-5-family models and handles tasks ranging from writing new features and fixing bugs to refactoring and generating tests. Codex is included in all ChatGPT subscription plans, starting with the free tier, and API access is billed by token usage.
It integrates with GitHub for code review and connects to Slack for notifications. The agent runs on GPT-5-family models and handles tasks ranging from writing new features and fixing bugs to refactoring and generating tests. Codex is included in all ChatGPT subscription plans, starting with the free tier, and API access is billed by token usage.