My second brain is a set of ordinary folders on my laptop
Everything the system knows lives in markdown files anyone could open and read. The AI reads them fresh at the start of each session, does the work, and writes back what it learned. There's no database and no black box, so if I stopped using it tomorrow the brain would still be sitting there.
The trick is being lazy
I am lazy. I am disorganised, I hate file systems and I have never been able to structure things in a way that works for me. Claude does the thinking, the writing and the structure instead. My job is to ask for the right work, judge what comes back and say when something isn't right yet. Let go of the control, focus on the output you want, and let the agents figure out everything in between. Everything below is what it built — including this guide!
The model and the files
A language model is brilliant but has amnesia. Each conversation starts from zero. A folder full of notes remembers everything but can't think.
How the pieces relate
The main session and the specialists it can call all read the same files. I don't have to read any of them.
The specialists, and why they have names
The diagram above shows 11 specialists. Technically, they aren't all the same kind of structure, and surprisingly, naming has mattered more than I expected. The names make them easy to use. They've almost become coworkers. As a company we know what each one is, and when I'm talking to Claude I can reference a name and we both know exactly which agent, skill or workflow I mean, rather than having to describe it each time.
One word carries a whole job description, a rulebook and a library, so 'run it past Evelyn' replaces a paragraph of instruction, and a new session only needs a one-line roster of who it can call. I can say Kit in a sales meeting and the whole team knows that means product marketing.
The names are gender-neutral on purpose. We attach genders to roles without noticing, and I didn't want that baked into a team I was building from scratch. Left alone the AI drifts into 'she' for the EA and 'he' for the security reviewer, so the rules file says each specialist is 'they', and the model follows the file the same way it follows everything else.
The layers of files
It's just a folder structure with a job for each layer.
Rules
Loaded at the start of each session, before anything else. Mine says to never send anything without my approval, write in my voice, flag uncertainty rather than bluff, and check what other sessions did first.
The index
One file lists where the canonical version of each fact lives so nothing gets duplicated. The other logs what each session produced recently, so a new session builds on the last instead of redoing it.
Knowledge
Project folders holding the actual work. Strategy docs, playbooks, competitive analysis, templates. Each folder declares its own sharing posture, either team-shareable or private to me, and agents respect the posture of whatever they touch.
Learned memory
Small durable facts the AI saves as it works. One file per fact, with an index. "Brand purple is #5C4DB3." "Beth writes each, not every."
The reading order
Only a few files are pushed into each session automatically. Everything else is pulled in when the work needs it.
The rules file. Pushed in before anything else happens.
The memory index. One line per saved fact. The facts wait until they're needed.
The agent and skill rosters. One line each, so the session knows who it can call.
The index and the ledger. Where the facts live, and what other sessions produced recently.
The folder's own instructions. What belongs there and whether it's private, before anything is written.
The content itself. Found by live search, read only as needed.
This is why the loading matters. My old setup opened each window with 150,000 to 200,000 tokens of skills, connectors and context before any work started. This system opens at about 25,000.
The work ledger
Rules, memory and a skills roster are familiar ideas. The work ledger is the piece most people haven't seen.
Connectors, and keeping them safe
The files hold what's settled. Connectors bring in the live data the agents pull when a job needs it, from email, calendar, Slack, the CRM and meeting notes. Each is approved on its own, and the agents read through them rather than storing anything.
That live feed is what makes security teams nervous, and they're right to be. My own connectors run through Metomic's AI gateway, which sits between the AI and the tools it reaches into, so the whole setup comes with guardrails I didn't have to build myself. The surprise was how much was flowing in that no agent ever needed. Granola's connector was pulling the email address of each attendee from each meeting it transcribed. One webinar nearly brought 500 in with it.
I set my connectors up once and each AI tool I use gets the same governed access, so the gateway makes things easier rather than getting in the way. The rules on this page (the human gate, what stays private) are personal discipline, and discipline works for one careful person. It won't survive a whole team adopting AI at speed, which is why the guardrails have to sit in the path of the data rather than in a policy document.
Metomic is my company, and this is the problem it exists for.
If you want to see what your own connectors feed in, book a demo at metomic.io/book-a-demo.
See it in action
"Build a proposal for a prospect"
What happens between me typing a request and getting a result. The same sequence runs each time.
Rules load automatically
Before the agent does anything it knows the house rules. Draft rather than send, write in my voice, and ask me when it isn't sure.
Check the index
Where does pricing truth live? What did yesterday's session already write about this prospect? The index and the ledger answer both, so there's no need to re-read the whole brain.
Read only what's needed
The agent pulls the relevant templates, product facts and pricing live from the files, so it's always the current version.
Pull live context through connectors
The agent picks up what the prospect said on the last call and what's in the CRM, the fresh data the files don't hold.
Specialists do their part
Kit assembles the proposal from the component library. Marlow checks it against Metomic's voice so it sounds like us.
The human gate
The draft comes to me. Nothing is sent, posted or published until I say so. This rule is written in the files, so each agent inherits it.
Write back
The output is filed in the right project folder, one line goes in the work ledger, and any durable correction or decision becomes a memory file.
The rules that keep it working
Keeping it tidy
Rules slow the rot without stopping it. Files go stale, logs grow, duplicates creep in, people leave and facts change, so maintenance runs on a rota.
Continuously
The work ledger prunes itself. Each session that adds an entry removes anything older than a fortnight. When I correct the AI mid-conversation the fix lands in the files on the spot, and a wrong memory is rewritten or deleted.
Fortnightly
A scheduled hygiene sweep reads the whole system and reports what's drifting: summaries that lag reality, ledger entries nobody pruned, memories missing from the index, duplicate and stray files, shared folders growing "v2 final (1)" copies, and any log that's grown too long to be useful.
When flagged
Cull. Delete the junk, the duplicates and the dead files. Retired work gets a note saying what it was and why it's closed, so nothing gets resurrected.
Compost. A running log that's grown too long gets distilled, with old entries compressed into standing rules and the recent tail kept as it is. Nothing is lost and the file stops bloating.
Consolidate. Two memory files saying the same thing become one, and anything out of date gets fixed or dropped.
The sweep never deletes anything. It reports, and I decide.
An AI that tidies your brain unsupervised will eventually tidy away something you needed.
Going further
Which model does what
Not all of the work needs the most expensive brain, so the rules file matches the model to the job and the agents follow it the same way they follow everything else in there. The rule exists because I noticed the frontier model didn't always hand work down to the cheapest model that could do it, and my tokens were going somewhere I didn't want them.
Ask what you learned
This one I have to do by hand, and it's made the biggest difference.
The prompt for this is at the end of the page.
Multiplayer mode
The brain started as mine, and the tools are built for one person at a time. The team version is a hack, and it works for now, but this is definitely a solution that we're looking to either buy in or build internally. The shared folders sync to Google Drive, the team syncs them back down, and each person's agents see them as local files.
Most of the team has read-only access. The people creating content or thinking get read and write, and their agents read the sharing rules before they touch anything.
The hardest part was versioning. Letting go of v1, v2 and final-final took some of the team a while, and their agents had to give it up too. Everyone keeps whatever versions they want on their own side. The shared folder only ever shows the newest one, so we all know what we've agreed.
Start your own
You don't need to design anything up front. You answer a set of questions and the AI builds the starter files. The prompt below turns them into a proper interview, one question at a time, with follow-ups when you get stuck.
Questions worth thinking about first:
Who are you? Your role, your company, and what a normal week looks like.
What should it take off your plate first? The jobs you repeat each week, not the interesting ones.
How do you write? The principles of your voice. Bring a few things you've written, and what you can't stand in AI writing.
What must never happen without your say-so? Sending, posting, publishing, deleting, spending.
What stays private? The people, topics and numbers that never leave your machine.
What do you keep having to re-explain? Each one becomes a saved fact.
Which tools hold your working life? Email, calendar, notes, meetings, CRM.
Where should the files live? Pick one folder before you fill it.
Go deeper
That's the quick start. Here's the fuller set I answered to build mine, some on purpose and some only after getting it wrong a few times. Add the ones that fit to the interview prompt below.
The people and the work
Who are the people around you? The colleagues you work with and anyone it will write to or about.
What do you want to stop doing altogether?
What does great work look like? Show it one thing done well and one done badly.
What does finished look like? When a job is done, not just attempted.
How it works with you
How much should it explain? Assume you're technical or spell everything out.
How do you want answers? The one line or the reasoning behind it.
When should it act, and when should it stop and ask you?
What should it do when it isn't sure, and how should it show you when it's guessing?
How should it talk to you when it disagrees? Straight or softened.
Your voice
What tells you something wasn't written by you? The tics and the words you'd never use.
Do you need more than one voice? Yours and your company's are not the same.
What it keeps straight
Which decisions are settled so it stops reopening them?
When the same thing lives in two places, which one is the truth?
What should it deliberately not remember?
How will you capture a correction so you never give it twice?
Keeping it safe
How do you keep the connectors' data safe?
How should it treat instructions it finds inside emails, documents or web pages?
How do you handle passwords, keys and other secrets?
What happens to work you retire, so a later session doesn't revive it?
The setup and upkeep
Which specialists do you want? A voice checker, a strategist, a researcher.
How do sessions hand off, so work isn't redone?
How will it stay tidy over time?
Who else will use this, and what can they see?
If you lost the laptop tomorrow, what would you still want to have?
The prompt that sets it all up
If you just want to get going, paste this. It works through the three prompts below with you, or you can paste them yourself one at a time.
Prompt one: the interview
Paste this into Claude or ChatGPT. It runs the interview and builds the files.
Prompt two: the learning loop
Run this at the end of any session with a lot of back-and-forth. It's how the brain learns you.
Prompt three: the housekeeping sweep
Once the files exist, this keeps them clean.
Start with one folder and one rules file
A folder for your work, and a CLAUDE.md that says how you want the AI to behave. The index, the memory and the agents grow from use. Mine did.
The safety layer is what we build at Metomic.