Cortex by The Second Brain Company
Give your AI the knowledge your team already has. Keep the decisions, the know-how, and the why behind your work in a shared Brain.
Cortexinstall https://www.thesecondbrain.company/Copy this into your ChatGPT or Claude app.
Simple by design
Your knowledge grows with your team. Your bill shouldn't grow with every person.
A small start. A smarter next conversation.
$0/ month
For your whole team
You own your knowledge.
Download your Markdown files anytime.
Available now
Start free today
For teams with more to remember.
Room to grow.
Private preview
You own your knowledge.
Download your Markdown files anytime.
Available by invitation
Private preview
Because knowledge needs a little tending.
A step ahead.
Pricing to be announced
You own your knowledge.
Download your Markdown files anytime.
Coming later
A look at what's next
One plan to start. More room, and a little more foresight, on the way.
Yours, on every plan
Your team's thinking belongs to your team. Download your knowledge any time as Markdown files: simple text that humans and AI can both read.
Keep a copy. Use it in other tools. Take it with you if you move on. What you've learned stays yours, wherever you go next.
Illustrative ChatGPT Work demo · Fictional product and prices
Fictional example in September 2026. Two knowledge lookups, followed by a saved change. This illustration does not send messages or change real knowledge.
Alex: What do we charge for Luma each month?
Cortex: Read pricing.md.
ChatGPT: Luma is $39 per month. That's the price for the whole team.
Alex: And what's the annual price?
Cortex: Read annual pricing.
ChatGPT: The annual plan is $390 per year, also for the whole team.
Alex: Make it $49/month from October 1. Keep the annual price the same.
Cortex: Updated pricing.md.
ChatGPT: Knowledge updated. Luma will be $49/month from October 1, 2026. The annual plan stays at $390/year.
The saved Markdown file keeps the current $39 monthly price and records the $49 price starting October 1, 2026. Annual pricing remains $390.
Explore your options
There is more than one way to keep shared knowledge. See what you gain, what you take on, and which approach fits the way your team works.
From "let me explain" to "you already know"
You've already done the thinking. Make it useful beyond the conversation where it happened.
The decision you just made. The reason behind it. The detail someone always has to explain. Capture it through conversation with your connected AI.
Keep useful knowledge together, organized by subject and owned by your organization. Your team has a place to find what's been learned.
Bring that context into the next AI conversation. Build on what your team already knows, without telling the whole story again.
A few useful details
Free supports up to 25 people per Brain, including the Owner. Pending invitations reserve places. Pro supports unlimited people. If a Brain moves to Free with more than 25 people, existing members keep their access; new people can join after Pro is restored.
Free includes a monthly AI recording allowance shared by your team. Larger imports and complex updates use more allowance. Cortex shows what's remaining and when it renews. You can keep searching saved knowledge when recording is paused.
Start on Free today. Get started by copying the install prompt into your ChatGPT or Claude app. Your assistant will guide you through email verification and creating a Brain. You can also accept an invitation to join your team's Brain.
A useful piece of context you want to keep: a decision, a process, a preference, or a fact about your work. Think "why we chose this approach" or "how we handle customer handovers."
No. There are no per-user fees on any plan. Free includes a shared Brain for your team, and paid plans will cover the whole organization.
Every plan includes read-only Git access, a standard way to download your files and their history. Your knowledge is saved as Markdown: simple text files that people and AI can read. Keep a copy, open it in other tools, or take it with you if you leave. Editing your downloaded copy won't change what's saved in Cortex.
Pro is available by invitation in the private preview, with more recording allowance and roles and access controls. Intelligence is coming later. Subscription pricing will be announced separately.
Knowledge changes as your team does. Intelligence is planned to automatically detect conflicting information and regularly scan for inconsistencies, helping you spot the things that need another look.
A little knowledge goes a long way
Start on Free with a shared Brain and a monthly AI recording allowance for your team. Connect ChatGPT or Claude and bring your knowledge into the next conversation.
install https://www.thesecondbrain.company/Copy this into your ChatGPT or Claude app.