OpenAI's Codex Accelerates Development with 70% PR Merge Increase, Highlighting Untapped Potential

OpenAI's Codex, an advanced AI software engineering agent, is demonstrating significant capabilities despite existing limitations, with its potential ceiling far exceeding current applications. Greg Brockman, President of OpenAI, recently stated on social media, "> codex is great despite so many (temporary) systems limitations. even before further model improvements, the ceiling is a lot higher than where we are now!" This sentiment underscores the rapid evolution and future promise of the AI coding tool.

Codex has evolved from a code autocompletion tool into a comprehensive agent capable of handling diverse software engineering tasks. Powered by models like GPT-5-Codex, it can write features, answer codebase questions, fix bugs, propose pull requests, and conduct thorough code reviews. This specialized version of GPT-5 is optimized for agentic coding, demonstrating proficiency in both interactive sessions and independent, long-running tasks.

The tool is now integrated across various developer workflows, accessible through ChatGPT Plus, Pro, Business, Edu, and Enterprise plans. Developers can utilize Codex via a Command Line Interface (CLI), an IDE extension for platforms like VS Code, the web interface, GitHub, and even the ChatGPT iOS app. This broad accessibility allows for seamless context transfer between local and cloud environments, enhancing developer productivity.

Companies are already leveraging Codex to streamline their development processes. OpenAI itself reports that Codex reviews the vast majority of its pull requests, catching hundreds of issues daily before human review begins. External users, including startups and large enterprises like Cisco and Rakuten, have seen a 70% increase in merged pull requests per week, with Codex automatically reviewing almost every PR to identify critical issues.

Despite its current advancements, OpenAI continues to develop Codex, with future plans for more interactive and flexible agent workflows. The vision is for developers to collaborate with AI agents across their tools, delegating complex tasks and focusing on strategic work. This ongoing evolution suggests that Codex is poised to unlock even greater efficiencies and innovation in the software development landscape.