Install the Second Neuron extension
Capture any article, documentation page, or snippet straight into your knowledge graph. Claude extracts the concepts, and spaced repetition brings them back at the right time.
Getting started
- Install the extension using the button above.
- Sign in at secondneuron.com and open Settings → API Keys.
- Generate a key (starts with
sb_) and paste it into the extension’s settings page. - Click the extension’s toolbar icon on any page — it extracts the article text locally, saves it, and Claude takes it from there.
What it can (and can’t) do
The extension only reads the page you’re actively viewing when you click the icon. It never runs in the background, never reads other tabs, and stores nothing except your API key and the URL of your server. Full details in our privacy policy.