OpenAI has hired the founders of Git AI, an open-source tool that tracks how much code is written by AI and measures the performance and cost of coding agents. Aidan Cunniffe and his Git AI co-founder Sasha Varlamov announced on LinkedIn late Friday night that they will be joining OpenAI's Codex team to provide businesses with better data on how coding agents perform and the returns they generate.
Cunniffe described the move as "Same mission, bigger stage." OpenAI's Thibault Sottiaux, member of technical staff working on ChatGPT and Codex, confirmed on X that the company plans to use Git AI's technology to help businesses understand Codex's impact. "We'll make it easier for businesses to see where Codex is making a difference when working through problems for individuals and teams," Sottiaux writes.
OpenAI shares our belief that users should have the data to compare model performance and understand the ROI of every token they spend.
Aidan Cunniffe
https://x.com/thsottiaux/status/2098569976143806918?ref_src=twsrc%5Etfw
Tracking AI-generated code
Git AI is an open-source Git extension that tracks AI-generated code. Every line of code is linked to the agent, model and prompts that generated it, preserving the context behind a change even after the code has been committed, merged or rebased. The tool enables teams to see how much AI-generated code reaches production, how often it's reworked, and where time and tokens are being spent.
Git AI supports a broad range of coding agents, including OpenAI Codex, Anthropic's Claude Code, Cursor, and Google's Gemini CLI, as well as background agents including Codex Cloud, Claude Web, Cursor Agent and Devin. After installation, supported agents report their edits to Git AI automatically. The tool can show the split between human- and AI-written code and trace individual lines back to the agent that produced them.
The story so far
Cunniffe founded developer tooling startup Optic in 2018, which built open-source tools around API development, before Atlassian acquired the company in 2024. He subsequently joined Atlassian as a principal product manager leading go-to-market efforts for developer tools.
Git AI began while Cunniffe was still at Atlassian. He and Varlamov started working on the project in the summer of 2025 as a side project, initially trying to answer one seemingly simple question: how much of their code was actually being written by AI, and what happened to that code afterwards? By the first major release in November, Cunniffe was publicly describing Git AI as a "weekend project" that had grown into something much larger. He subsequently left Atlassian in January 2026 to turn Git AI into a company, building a commercial business around the open-source project.
Now, less than a year later, Cunniffe and Varlamov are heading to OpenAI. It is not yet clear what that means for Git AI as a commercial business, but with both founders joining OpenAI, it appears likely that the standalone business will be wound down, while the open-source project continues. Cunniffe says OpenAI will continue backing the open-source project. "We'll keep investing in open source, while also giving enterprises the data they need to build effective software factories," he writes.
Source: The New Stack