I Tried OpenAI's New Codex Agent. Here are my First Impressions (It's Really Good)

OpenAI just dropped Codex, a beautiful new GUI for their AI coding agent, and after a day of testing, I'm genuinely impressed. Let me show you why this might change how developers work with AI. In this video, I take you on a complete tour of OpenAI's new Codex application for macOS. We explore the stunning interface, the impressive multi-threaded workflow, automations, skills, and MCP server integrations. Then I put it to the test by building a complete Java 25 vending machine CLI application from scratch, including adding JSpecify for null safety. Key Takeaways • Codex's thread-based workflow lets you multitask across multiple projects simultaneously • GPT 5.2 Codex is now 40% faster - a huge improvement for developer workflows • Built-in support for Git work trees enables parallel AI-driven development • Automations can scan commits for bugs, draft weekly notes, and summarize stand-ups • Skills and MCP servers extend Codex's capabilities to tools like Notion and Sentry Timestamps 0:00 - Intro & First Impressions 0:45 - Codex Website Tour 2:15 - Multi-Platform Support (Mac, CLI, Web) 3:00 - GPT 5.2 is 40% Faster 3:45 - Project Setup: Vending Machine CLI 5:00 - Thread-Based Workflow Explained 6:15 - Automations & Skills Deep Dive 8:00 - MCP Servers & Git Integration 9:30 - Building the App with Codex 11:00 - Reviewing Generated Code 12:30 - Running Tests & Demo 13:30 - Adding JSpecify Null Safety 14:45 - AI-Generated Commit Messages 15:15 - Final Thoughts & Wrap Up 🔗Resources & Links mentioned in this video: Codex: https://openai.com/codex/ Have you tried OpenAI Codex yet? Drop your thoughts in the comments below - I'd love to hear how it's fitting into your workflow! 👋🏻Connect with me: Website: https://www.danvega.dev Twitter: https://twitter.com/therealdanvega Github: https://github.com/danvega LinkedIn: https://www.linkedin.com/in/danvega Newsletter: https://www.danvega.dev/newsletter SUBSCRIBE TO MY CHANNEL: http://bit.ly/2re4GH0 ❤️