second-brain

Application that permits user to store everything that he knows, an LLM reviews the data to suggest improvements

Local development

node src/index.js

Then open http://localhost:3000.

PowerShell may block npm run dev because of script execution policy. In that case, use:

npm.cmd run dev

GitHub Pages frontend

GitHub Pages should be configured with:

• Source: Deploy from a branch
• Branch: main
• Folder: /docs

The public frontend URL is:

https://epap28.github.io/second-brain/

docs/config.js points the frontend to the hosted API.

Free Cloudflare backend

The public frontend is hosted by GitHub Pages. The API runs on a Cloudflare Worker, and the app data is stored in Cloudflare D1.

Install Wrangler:

npm.cmd install --save-dev wrangler

Log in to Cloudflare:

npx.cmd wrangler login

Create the free D1 database:

npx.cmd wrangler d1 create second-brain-db

Copy the returned database_id into wrangler.toml, replacing REPLACE_WITH_CLOUDFLARE_D1_DATABASE_ID.

Create the schema:

npm.cmd run d1:schema

Add the first-admin setup token as a Cloudflare secret:

npx.cmd wrangler secret put SETUP_TOKEN

If SETUP_TOKEN is not configured, the Worker can still use the old SECOND_BRAIN_PASSWORD secret as the setup token.

Invite request emails use client-side email actions. Requests are stored in D1, then the app shows links for Gmail, Outlook, the local mail app, and copying the message.

Deploy the Worker:

npm.cmd run worker:deploy

Cloudflare will print a URL like:

https://second-brain-api.<your-subdomain>.workers.dev

Copy that URL into docs/config.js, then commit and push.

Authentication flow

Create the first admin account once the Worker is deployed:

$body = @{
  email = "your-email@example.com"
  password = "your-admin-password"
  setupToken = "your-setup-token"
} | ConvertTo-Json

Invoke-RestMethod `
  -Method Post `
  -Uri "https://second-brain-api.<your-subdomain>.workers.dev/api/auth/setup" `
  -ContentType "application/json" `
  -Body $body

Then sign in from the GitHub Pages app with that email and password.

To create invitation codes:

1. Sign in as the admin user.
2. Open the Invite requests panel on the home screen.
3. Click Send code on a pending request.
4. The code is copied and the app shows Gmail, Outlook, local mail app, and copy-message actions.
5. Open one of the email actions, then click Send in your email app.

Users create their account from the First-Time Access section with the invitation code and a new password.

Git deploy

git add .
git commit -m "Add user authentication"
git push origin main

Data privacy

data/second-brain.json is ignored for future commits, but if it was already committed to GitHub, remove it from the repository history or at least untrack it before pushing new private data.