My extension had a bug that's the worst kind: it looked like it worked.
You'd save a Claude conversation, open it up, and there'd be your questions — every single one of them — and none of Claude's answers. Half the conversation, gone, but neatly. No error, no crash. Just quietly wrong.
I want to walk through the day I spent chasing this, because it taught me something I keep having to relearn.
Some background. My extension reads AI chat pages — ChatGPT, Claude, Gemini, Perplexity — and pulls the conversation out so you can save it. None of these sites give you an API for that. So you're reading the raw HTML, hunting for the CSS selector that wraps each message. And those selectors are not documented anywhere, because they were never meant for you. They change whenever the site ships a redesign.
Here's the mistake I made, more than once: I guessed.
