Claude Code and OpenAI Codex Do Track You

Recently, after hitting my Claude Code Max limit, I switched over to OpenAI Codex to continue my work.

I immediately felt the switching cost. Codex misunderstood specific code written by Claude.

In particular, the app I was writing allows the user (a parent) to create multiple children’s profiles. And there are terms Claude used in the code:

• Active = child profiles unlocked with subscriptions
• Selected = child profile currently selected in the mobile app.

In the first session, Codex confused active as selected and proceeded to mess up my code. So, I had to explain the concept to it.

My first thought was, maybe Claude and Codex have their own language preference. So, it was natural that Codex misunderstood the term Claude used.

But, a friend of mine has a different hypothesis. He proposed that maybe the AI labs have a RAG system to track our preferences server-side.

I thought it was quite possible. As that could create a data network effect to increase the user switching cost. But we have no proof.

The proof then came on the same day when I switched from my coding project to writing a LinkedIn article. Codex unexpectedly showed “No tests run”, when my LinkedIn article repo has nothing about tests.

To be clear, I started a new session. And I didn’t add any of my preferences in local memory. I always add preferences to the project in the project guidelines.

What is your experience? Do you think CLI tools like Claude Code and OpenAI Codex track you?