Build your own second brain for your business: a founder's step by step.
Seven steps, what to put in first, when a personal second brain is enough, and the free skill that writes your first twelve pages. Written by a firm that runs its own business on one. Published 5 November 2026.
The short answer
To build your own second brain for your business, decide the questions it must answer, then write one plain markdown page per workflow, system, decision and person, linked to each other. Capture every call and meeting from day one. Teach Claude to read the right page before it acts and write back what it learned. Ask it daily, correct the page rather than the chat, and let a daily check tell you which pages are missing. A personal second brain is enough while only you act on it; the moment a colleague or an AI agent has to, the business needs its own.
Build your own second brain in seven steps
This is the order we would follow again. Each step is small on its own; the compounding comes from doing them in order and not stopping.
- Step 1
Decide the questions it must answer
Write down the ten questions you are asked most, by staff, by customers, by yourself at eleven at night. How do we quote? Who owns the supplier relationship? Why did we stop doing that? A second brain exists to answer questions; start from the questions, not from the folders.
- Step 2
Start with workflows, systems, decisions, people
Four kinds of page do most of the work. A workflow page for each job the business repeats. A system page for each tool and what it is the source of truth for. A decision page for each choice that was settled, with the reason. A page for each person and what they own. Everything else links into these.
- Step 3
One page per thing, with links, in plain markdown
One page, one subject, a one-line summary at the top, and links to the pages it touches: the workflow links to the system it runs in and the person who owns it. Plain markdown files in a folder, not a database and not a document nobody opens. Links are what let a person or an AI follow a question from one page to the next.
- Step 4
Capture every call and meeting from day one
The brain grows from what happens, not from what you remember later. Record the call, write the notes while they are fresh, and link them to the client, the decision and the workflow they touched. Ours holds calls, meetings and decisions since January 2026, and that habit is the whole reason it is worth asking.
- Step 5
Teach Claude to read and write it
A skill tells Claude where the pages live, what each type of page is for, and to read the relevant one before it acts and write back what it learned when it finishes. The free starter skill below does the first part: it interviews you and writes the first twelve pages. From there, every piece of work leaves the brain a little better.
- Step 6
Ask it daily
Use it as the first place you look, not the last. Ask the assistant that has read the pages before you ask a colleague. When the answer is wrong, correct the page, not the chat, so the next answer changes for everyone. A brain nobody asks goes stale in a month.
- Step 7
Let the daily eval tell you what is missing
Every morning, a check reads what the AI did the day before: the question nobody had a page for, the skill that loaded and was abandoned, the job still done by hand. Each one is a page to write or fix. That list is a far better plan than documenting the business from a blank sheet.
What to put in first
Twelve pages, in an order that gets the business talking to itself fastest: what we do and who for, what we sell, how work flows, who decides what, which tool holds which truth, the rules nobody wrote down, how we talk, recurring jobs, the numbers that matter, recent decisions and why, the glossary, and who to ask. We wrote the reasoning up as what a small business should put in first, and the free starter skill below writes those twelve pages with you.
Resist the urge to import everything. A brain with a few dozen accurate pages, each with an owner, beats a folder of ten thousand documents nobody can tell apart. How the pages then join into a graph a whole team and its agents can follow is explained in the knowledge graph behind it.
When a personal second brain is enough
Most founders start with a personal second brain, and for a while it is all they need. The line is crossed the first time someone else, a colleague or an AI agent, has to act on the pages without asking you.
| Step | Personal | The business's own |
|---|---|---|
| Who acts on it | You | A second person, or an AI agent, without asking you |
| Pages are about | What you are thinking about | How the work runs: workflows, systems, decisions, people |
| When two notes disagree | You know which you meant | Someone has to settle it and the page has to show who did |
| Who can see what | Just you | By role: finance pages are not open to everyone |
| Who owns it | You | The business |
If you are on the left of that table, you want a personal second brain, and we make one: Hey Bastion is built for a person, on their phone, and it is not a Sentry AI service. If you are on the right, read a second brain for your business for what changes when a team shares one, and ours to see one running.
Free, no call needed
The starter skill and the playbook
Two things to take with you. Both are free and neither asks you to book anything.
The second brain starter skill
Install it in Claude. It interviews you one question at a time, writes the first twelve linked markdown pages in your own words, then lists the gaps and the three pages to write next.
The second brain starter playbook
The twelve pages in order, what each one holds, who owns the brain, the update trigger, where to keep it so your AI tools can read it, and the mistakes that make one go stale.
Frequently asked questions
How long does it take to build a second brain for a business?
The first few pages take an afternoon; the rest follow as you work. A useful brain, one a new hire or an AI assistant can work from, is a few weeks of writing things down as they come up. It is never finished, and it should not be: the point is that it grows with the work.
What tool should I write it in?
Plain markdown files in a folder, linked to each other. Obsidian is the common choice for a founder because it shows the links as a graph, but the files are what matter, not the app. Plain files are what let Claude, ChatGPT or any other assistant read the same pages without a conversion step.
Is a personal second brain enough, or does the business need its own?
If one person does the thinking and the notes only have to make sense to them, a personal second brain is enough, and Hey Bastion is built for exactly that. The moment a second person or an AI agent has to act on the pages without asking you, the business needs its own: typed pages, an owner for each, and somebody who settles disagreements.
Do I have to write it all myself?
No. You answer questions; the starter skill writes the pages and lists the gaps. After that, most of the writing happens inside the work: a call is captured, a decision is recorded, a correction becomes a rule. The founder's job is to decide what the brain must be able to answer and to settle the arguments.
How does Claude read and write it?
Through a skill that knows where the pages live and what each type of page is for. It reads the relevant page before it acts and writes back what it learned when it finishes. The free starter skill is the simplest version of this; a team brain adds access by role and a daily check for pages that have gone stale.
What does the daily eval have to do with a second brain?
It is how you find out what is missing. Every morning it reads what the AI did the day before and notices the questions people asked that no page answered, the skill that loaded and was abandoned, the job still done by hand. Each of those is a page to write or fix, and it is a far better to-do list than trying to document the business from a blank sheet.
Read next
More on the second brain
The second brain
What one is made of, how one gets built, and what it is not.
What is a second brain for a business?
The plain definition: linked pages on workflows, systems, decisions and people that every agent reads and writes, and why a wiki is not one.
A second brain for your team, or just for you
How the second brain idea changes when a whole team, and every agent working for it, has to share one, and where to go if it is only for you.
Our second brain, live and growing
Calls, meetings and decisions since January 2026, as linked pages our team and our agents ask every day. The count, the departments, and how it grows.
Rather see one running first?
A short call on what your business would put in it first, with a live second brain on the screen. No deck.
Ask an AI about this page
Opens the assistant with this page loaded: read it, summarise it, cite it.