Claude knows you better when you take 5 minutes to configure it.
Who it's for
Anyone who uses Claude more than once a week. If you spend the first minutes of every conversation re-explaining your job, your tone, and your constraints, you're burning energy for nothing. Five minutes of setup upfront, and Claude starts every exchange already briefed.
No need to be a developer. Everything happens in claude.ai settings.
What you can do
Style and persona. You pick the tone (direct, explanatory, concise), the default output format, and the pronoun Claude should use with you. Three built-in presets (normal, concise, explanatory) plus as many custom styles as you want.
Business context. You tell Claude who you are and what you do. Your industry, company size, clients, constraints. Claude stops guessing and starts proposing things that actually fit your case.
System instructions. Permanent rules that apply to every conversation. Examples: "always answer in English", "never use em-dashes", "cite your sources when you run a web search", "if you're not sure, say so".
Memory. Claude automatically remembers what you tell it that matters. You mention an ongoing project, a business constraint, a formatting preference, it keeps that for next session. You can also ask explicitly: "remember that I'm working on X".
Preferred artifacts. You can set the output formats you want by default. Markdown instead of raw prose for docs, HTML slides for presentations, strict TypeScript for code. Claude sticks to it without you having to repeat yourself.
A concrete block to copy
Example for a freelance marketer. Paste this into your system instructions:
I'm a freelance marketer based in Bordeaux, B2B SMB clients.
Answer in English, direct tone, no em-dashes.
For every action you suggest, give me the short version first.
Before config, the same question ("I need ideas for my newsletter") returns a generic list of 10 formats. After config, Claude suggests 3 B2B angles sized for your business, in English, no fluff.
How much it costs
Included in every plan: free, Pro, and Max. Personalization isn't a premium feature, it's the baseline. You can set everything up on the free plan.
When to use it vs. something else
Personal config on claude.ai for anything tied to your profile and global preferences. That's what this chapter covers.
Per-project config via Claude.ai Projects if you want to isolate a context (a client, a specific topic, a sensitive folder). We'll come back to this in the Projects and Artifacts chapter.
Per-codebase config via CLAUDE.md in Claude Code if you write code. Same logic, at the repo level. Covered in chapter 6 on Claude Code.
Set up global system instructions first. You'll add per-project configs later, once you see what actually repeats.