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Chrome extension

Stop re-explaining your browser work to your agents.

Turn on sites like ChatGPT or Linear. What you decide there becomes short memories, formed on your laptop. Your first 5 wait for your OK, then 10 minutes so you can untick any. Your AI agents recall them from Substrate.

Start your Substrate trialWhat it never reads

Coming to the Chrome Web Store

Needs a Substrate account. 7 days free, no card, then $20 a month.

Example memory

Decide in one chat. Every agent recalls it.

Memory

Agreed to move the pricing page launch to Oct 30, after the onboarding fix ships.
From: ChatGPT, “Launch plan”Why: you agreed on a date

A week later, in Claude

When does the pricing page go live?

ClaudeOct 30, after the onboarding fix ships.

It found the memory in Substrate.

Where memories go

Into Substrate

Memories land in Substrate, a shared memory of your company that you and your agents both work from. Claude and your other AI agents connected to Substrate recall them.

How it works

Three steps.

  1. 01

    Turn on a site.

    It's off everywhere until you do. Chrome asks you for each site, and you can take it back any time.

  2. 02

    Memories form on your laptop.

    Chrome's built-in AI (or simple rules, if your laptop can't run it) writes short memories from the page you have open. The page itself stays on your laptop.

  3. 03

    Untick what you don't want.

    New memories wait in the side panel. Your first 5 wait for your OK. After that, the rest go to your Substrate after 10 minutes, or whenever you set.

The side panel

Memories wait in a side panel first.

Your first 5 wait for your OK. After that, 10 minutes by default. If you don't open the panel, they're sent when the wait ends. Each one shows the text, where it came from and why it was formed. Edit or untick it, or send it now. Unticked memories are deleted from your laptop and never sent.

Choose when memories are sent:

  • right away
  • after 1 minute
  • 10 minutes
  • 1 hour
  • only when you approve

Later, press Forget in the Sent tab and your agents stop recalling it.

Substrate Memory in Chrome. A ChatGPT chat about agency pricing on the left, and the side panel on the right, where 4 memories wait. The first, from that chat, sends in 7:11 unless you untick it.

Safety

What it reads and never reads

What it reads

  • The page you have open, on sites you turned on. On ChatGPT, Claude and Gemini that's the conversation on screen, your messages included.
  • Text you select and save with right-click

What it never reads

  • Password and payment fields, or text you're still typing
  • Other tabs, browsing history, cookies
  • Incognito windows - it can't run there
  • Known banking, health, email and password manager sites, even if you turn them on
  • Screenshots or keystrokes

What leaves your laptop

  • Only memories you don't untick: up to 600 characters each, plus the page title and domain. Never the page's address.
  • API keys, tokens and card numbers are removed first, on your laptop. Emails and phone numbers too, by default. Names aren't, and removal works by pattern and can miss things. That's why memories wait for you.
  • Sent over HTTPS to your Substrate account, and nowhere else. Private to you, and not used to train AI. From there, the Substrate Privacy Notice applies.
The side panel's Waiting tab. One memory from github.com is unticked and marked “Skipped, deleted at 3:45 PM”, so it is never sent. The next one is ticked.
A ChatGPT chat that contains a live Stripe key. The memory formed from it says “API key” where the key was, and notes “1 API key removed”.

No analytics or tracking, and no remote code. The code isn't minified, so you can read what it does.

Full policy: Chrome extension privacy

FAQ

Questions, answered plainly.

Does Substrate see my browsing?

Only the memories you send, with the title and domain of the page each one came from. Your browsing itself stays on your laptop.

How is this different from ChatGPT or Claude memory?

These memories go to Substrate, so every agent you connect to it can recall them. A decision from a ChatGPT chat is there for Claude too.

What if my laptop can't run Gemini Nano?

Gemini Nano needs about 22 GB of free disk and 16 GB of RAM or a GPU with more than 4 GB. Without it, the extension uses simple rules on your laptop instead. Memories are rougher, but still formed locally. No page text goes to a server or cloud model.

Can my team see my memories?

No. They're private to your account. They don't appear on your pages, and sharing a page doesn't share them.

Which sites does it work on?

Any site you turn on. There are presets for ChatGPT, Claude, Gemini, Linear, Notion, GitHub, Jira and Confluence. On any other site, select text and right-click "Remember in Substrate".

Does it capture passwords or private messages?

It never reads password or payment fields, or text you're still typing. Known email and messaging sites are never read, even if you turn them on. If something private gets into a memory anyway, untick it before it's sent.

Can I pause it?

Yes. For an hour, until tomorrow, or until you turn it back on.

How do I delete what it saved?

Unticked memories never leave your laptop. For sent ones, press Forget in the Sent tab and your agents stop recalling it. Substrate keeps a record of it. To have data deleted from your account, email pavel@trysubstrate.co. "Delete all local data" clears the extension.

What does it cost?

The extension needs a Substrate account: 7 days free, no card, then $20 a month.

Try it on one site.

Start your Substrate trial

Coming to the Chrome Web Store

Needs a Substrate account. 7 days free, no card, then $20 a month.

Chrome on desktop. Not in incognito.