The Business Brain: have Claude interview you and write the one document that teaches AI your business

Step 1: Let Claude interview you

Set aside about half an hour with no interruptions. Open a new chat and paste this in.

Talk, don't polish. Typos are fine. Use voice dictation if it's faster.

Step 2: Give it real examples of your writing

Rules about your tone help a little. Real examples help a lot. Gather three to five things you wrote yourself: a customer email, a social post, a text to a client, a page from your website.

Step 3: Have Claude write the document

Step 4: Check it and fill the gaps

Then read the final version yourself. If a line isn't true, fix it now. Save it as a document called business-brain.

Step 5: Put it in a Claude Project

1. Create a new Project in Claude. Name it after your business.
2. Upload the business-brain document to the Project knowledge.
3. Paste the instructions below into the Project instructions.
4. In ChatGPT, do the same with a Project or a custom GPT.

Now every chat you start inside that Project already knows your business. You never paste your background in again.

Step 6: See the difference (before and after)

Here's what that looks like for a small bookkeeping firm that works with local restaurants.

Before, in a normal chat: "Write a follow-up email to a lead who asked about our services." Claude writes a polite, generic email about "streamlining your finances" and "tailored solutions". It could be from any firm anywhere.

After, in the Project with the business brain, same request. Claude writes a short email in the owner's voice. It names the monthly bookkeeping package and its real price, speaks to the restaurant owner's actual problem (doing the books late at night after closing), answers the question most leads ask about switching from their current bookkeeper, and skips the words the owner never uses. Same AI. The only thing that changed is what it knows.

Compare the two answers side by side. That gap is what the business brain gives you.

Step 7: Keep it updated, and the rules

A business brain goes stale when your prices, offers or customers change. Update it the day something changes, and do a quick check once a month.

Then replace the old file in the Project knowledge with the new one.

Rules and common mistakes:

• One brain, one document. Don't scatter it across ten files.
• Real examples of your writing beat descriptions of your voice.
• Never let it make up proof. Use MISSING and fill it in yourself.
• Keep private data out: no passwords, bank details or private customer information.
• Update prices the day they change.
• Reuse it everywhere. Every Project and agent you build can read the same business brain.