How to build a brand brain for AI

A brand brain is one document that tells an AI how your brand talks, what it can claim, and what it must never say. Without one, every prompt starts from zero and the output sounds like everyone else.

Here is how to build one in seven steps, and where to put it so it gets used.

What goes in a brand brain

Keep it to one page per section. Short beats complete.

• Who we are and who we write for.

• Voice: how we sound, in plain words.

• Words we use and words we cut.

• Facts to keep consistent: prices, turnaround, plan names, claims.

• Examples of copy that is on voice, and examples that are not.

• Visual rules for image prompts: colors, materials, what to avoid.

A sample outline

Start from this skeleton and fill it with your own words.

1. WHO WE ARE: one sentence. WHO WE WRITE FOR: one sentence.
2. VOICE: six lines. Direct, short, specific, honest.
3. WORDS WE USE / WORDS WE CUT: two short lists.
4. FACTS: prices, plans, turnaround, claims. Use only these.
5. EXAMPLES: three on-voice, one off-voice with the reason.
6. VISUAL RULES: colors, materials, what never appears.
7. RULES: no invented numbers, no filler, one next step per piece.

Step 1: write the voice in six lines

Describe how you sound the way you would to a new hire. Ours: direct, clear, impactful, a little blunt. Short sentences. Numbers beat adjectives. If a line could appear on any company's site, rewrite it.

Step 2: list the words to cut

AI loves filler. Ban it by name. Ours is a plain list of tired marketing words and stock openers. Yours should name the words you keep seeing in AI drafts. A banned list is the fastest way to change output.

Step 3: add the facts

Write down every fact the AI may repeat: prices, plan names, turnaround, team size. Then add one rule: use only these facts, never invent numbers. This stops the most costly mistake, a confident wrong price.

Step 4: paste three real examples

Pick three pieces you are proud of and mark what makes them work. Pick one you dislike and say why. Examples teach tone faster than rules do.

Step 5: add visual rules

If you generate images, write the style once: materials, colors, lighting, and what never appears, such as faces, neon or text inside the image. Reuse the same lines in every prompt.

Step 6: load it where you work

Put the document where the AI reads it every time. In Claude, Projects let you upload documents to a knowledge base and add project instructions. Anthropic's page says Projects are available on all plans, and that retrieval-based expansion of the knowledge base needs a paid plan (read 27 Oct 2026). Most other AI tools have a similar feature. Check the current limits in your tool's help page.

Put the voice, the cut list and the facts in the instructions. Put the longer examples in the knowledge files.

Step 7: test, then fix the document

Ask for three things: a LinkedIn post, an email subject line and a landing page headline. Read the output against your voice. When it misses, fix the brain, not the one reply. Add the missing rule, then run the test again.

A line to paste first

If your tool has no place for instructions, paste this at the top of every chat and add your facts: “Write in a direct, short, slightly blunt voice. No filler, no marketing clichés, no em dashes, no lists of three. Use only these facts: [facts]. Do not invent numbers.” It is the opener from our own writing guide.

Why it works

An AI answers from what it has in front of it. A generic prompt gets a generic average of the internet. A brand brain puts your voice, facts and rules in front of it every time, so the output starts closer to what you would write. It does not replace an editor. You still read every line before it goes out.

Who owns it

Give the brain one owner, usually whoever runs marketing. Everyone else sends changes to that person. Two people editing the same document is how a wrong price comes back.

Common mistakes

• Writing a 20-page brand book and calling it a brain. Short and specific works better.

• Describing the voice with adjectives only. Add examples.

• Skipping the facts section, then correcting wrong prices by hand.

• Never updating it.

Keep it alive

Review the brain once a month. Add new facts, new examples and new banned words. A stale brain repeats an old price.

Brand brains are not only for small teams. Superside lists a Brand Brain among the platform tools covered by its $1,000 monthly software fee (read 27 Oct 2026). The idea is the same: one source of truth the AI reads first.

Want a designer who reads your brand brain and uses AI with taste? Book a call.

What we could not verify

Tool limits and plan terms change. We checked only the Anthropic page linked above. Confirm file limits for any other tool before you rely on them.