Rent the model.
Own the brain.

Second Brain OS is an AI brain FCT installs around your business, as plain files on your own machine. Most assistants are the model: when the chat ends, the context is gone. Here the assistant is a folder. It holds who you are, your business context, a memory of everything you have done together, and the skills and tools to act on it. A capable model such as Claude plugs in to do the thinking, and for that session it becomes your assistant. Swap in a sharper model next year and the brain stays exactly where you left it. The folder is organized into identity, context, workspace, memory, skills, setup, automations and database. During onboarding FCT wires it into the tools you already run, including Google Workspace, Apple's Mac apps, Telegram, GitHub, Cloudflare and MCP servers, and writes your recurring work down as skills it can run. Base setup usually takes one to two weeks. The intelligence is the only interchangeable part. Everything that makes the assistant yours lives in files you own and keep.

It separates the intelligence from the brain. Most AI tools are the model. When the chat ends the context is gone, and when you switch providers you start over, renting the intelligence and owning nothing you built. Second Brain OS turns that around. One startup file tells any model (Claude, Codex, GPT, or whatever comes next) how to wake up as your assistant, with all of its memory and skills intact. No vendor is load-bearing and no account holds your data. Underneath runs a memory on two layers: durable facts loaded at every session start, and daily logs built automatically from your transcripts, so the assistant reads back the whole story instead of waking up blank. A weekly pass keeps that memory clean and current. You rent the thinking. You own the brain, as files on your own machine.

You own every file in the workspace from day one. Second Brain OS lives as plain files on your own machine: identity, context, memory, skills, automations and more. FCT's contribution is the framework, the setup and the tool wiring, not the content. Move the folder to a new machine, hand it to a different model, or read it yourself ten years from now, and it all still works. It runs on your own AI runtime, Claude Code or Codex, which needs a paid account starting around 20 dollars a month. You own that account and pay the provider directly; FCT recommends one and sets it up during onboarding. Day to day you open the folder and talk to your assistant. It works on Windows and Mac. FCT also engineers the runtime underneath as its own service. Its own harness runs the company, and 18 different models have run on it across 76 active days and 2,789 sessions as of September 11, 2026, so the workspace you get is built by people who build the layer under it too. Handoff includes a guide to what each folder does and how to extend it, plus an optional retainer for upkeep and ongoing improvement.

The memory works on two layers, so the assistant never resets between sessions. The first layer is durable facts loaded at every session start: the things that should always be true in context. The second is daily logs built automatically from your session transcripts, a searchable record of everything that got built, decided, and why. Start a fresh session and the assistant reads back the whole story instead of beginning blank. A weekly pass keeps the memory clean and updates facts that have aged, so the assistant does not quietly go out of date. The major AI labs now sell this kind of self-refreshing memory inside their own products. Second Brain OS gives you the same shape as portable files you own and any model can read. On top of that, a growth loop reads your recent logs, finds the work you repeat, and proposes it as a new skill for you to approve. The longer you run it, the more it knows you.

Base setup usually takes one to two weeks. Add-ons extend that, depending on scope. Setup runs in five steps. FCT copies the framework into your workspace folder. A guided onboarding interview fills in your identity, plan, memory and business context, and names your assistant. FCT wires in the tools you live in: Apple, Google Workspace, Telegram, Cloudflare, GitHub, MCP servers. Optional add-ons or automations are layered on. Then FCT verifies the startup context, the memory writes, and at least one working tool before handoff. The add-on menu is built, not planned: Morning Brief, Email, Accounting & Finance, Business Integration, Coding & Projects, Personal Tracking, School Memory, and Job-Search CRM, each configured to how you work. An owner running a company, a student mid-semester, and a job-seeker get three different brains from the same framework. Each add-on can be bought upfront or added later.