The ADHD Developer's Guide to CLAUDE.md

I reopened a file I had already fixed that morning. Not metaphorically. I literally re-fixed a bug I had closed four hours earlier, because between the fix and the reopen, my brain had quietly deleted the entire afternoon. That is the ADHD tax most productivity advice never names: it is not that you cannot focus, it is that the working model of what you were doing does not survive the gap between sessions. CLAUDE.md is the cheapest fix I have found for that specific failure. This is the companion to my Claude Code ADHD workflow ; that post is the full system, this one zooms all the way in on the single file doing most of the work. What Is CLAUDE.md, Actually? CLAUDE.md is a Markdown file that Claude Code reads automatically at the start of every session. You do not paste it. You do not remind Claude it exists. It just gets read, every time, before the first line of work. There are two places it lives: ./CLAUDE.md at a project root holds rules for that project: the tech stack, the conventions, the gotchas. ~/.claude/CLAUDE.md holds your global rules: things true across everything you build (your voice, your defaults, the things you never want re-litigated). For a neurotypical developer this is a convenience. For an ADHD developer it is a prosthetic. The difference is what the file is replacing. Why CLAUDE.md Is External Working Memory for ADHD Brains Working memory is the mental scratchpad that holds "what I am doing right now and the three things I just decided about it." ADHD shrinks that scratchpad and makes it leaky. Every interruption, a Slack ping, a stray thought, a context-switch to email, knocks items off it. When you return, the scratchpad is blank and you rebuild it from scratch. The American Psychological Association puts the rebuild cost at roughly 23 minutes per context switch for a typical brain. For an ADHD brain that involuntarily switches more often and rebuilds slower, the real cost is higher and it compounds. Ten switches a day is not ten minutes