Europe 2026
OpenAI Codex Masterclass — Vaibhav Srivastav & Katia Gil Guzman
Vaibhav Srivastav , Katia Gil Guzman
Overview
This talk introduces OpenAI's Codex, an AI software engineering agent capable of performing a wide range of tasks beyond just writing code, such as running commands, executing tests, and exploring codebases. It highlights the underlying models, the unified agent harness for managing agent behavior, and the various interfaces through which users can interact with Codex, including a dedicated app, IDE extensions, and CLI. The presentation emphasizes the continuous improvement of Codex through model advancements and the development of features like plugins and automations to enhance developer productivity.
Who should watch
- AI engineers and developers looking to leverage AI for coding and software development tasks.
- Product Managers and builders interested in integrating AI agents into their workflows and products.
- Users seeking to understand and utilize advanced features like plugins, automations, and sub-agents.
- Developers interested in improving code quality, security, and development speed.
Key takeaways
- Codex is an AI software engineering agent built on foundation models like GPT-4, enhanced by a unified agent harness for tool execution, environment setup, and safety.
- It offers multiple interaction surfaces: a Codex app, IDE extensions, CLI, and integrations with platforms like Slack and GitHub.
- New features include plugins, which bundle skills, apps, and MCP servers into reusable workflows, and automations for background tasks like scheduled summaries or data updates.
- Codex provides advanced code review capabilities, with 100% of pull requests across OpenAI repos reviewed by Codex by default.
- Sub-agents allow for the decomposition of master tasks into parallel, independent tasks handled by specialized agents, enabling complex operations like reviewing multiple code files simultaneously.
- The platform is rapidly evolving, with recent additions like mini models for sub-agents, faster token delivery via WebSockets, and a fast mode for increased speed.
- Experimental features like Guardian Approvals aim to reduce human fatigue by verifying privileged tasks, and Hooks allow programmatic actions based on events like session start or tool use.
- Codex Security is a feature designed to find and fix vulnerabilities in GitHub projects, and a Cloud Code plugin enables its use within cloud coding environments.
Notable quotes
Codex is an open AI's software engineering agent. It can do much more than that. It can run commands. It can run tests. It can explore code bases. It can really do everything that a software engineer would do.
*Codex code review is one of the best in the industry right now.*
Sub agents is essentially the ability wherein you can spin off a master task into decomposable, parallel, and independent tasks, which you can hand off to agents.
Unofficial community note. Prefer the recording for nuance.