Inspire9 · Melbourne · 30 July 2026

Build a Second Brain
with Obsidian & localAI

Leonardo Rincón · Co-founder, SolidAI
Your notes, your server, your AI — nothing leaves your hands.

What it is

Obsidian is a note-taking app
for your desktop and phone

You write notes as plain text (Markdown) files — no proprietary format
Everything lives in a folder on your own device, called a vault
[[Links]] between notes turn your vault into a network of ideas
Free to use, with plugins that add sync, publishing, and even AI

Second Brain.md ● Writing… ✓ Saved

# Second Brain

- Capture ideas in **Markdown**

- Connect them: [[Zettelkasten]]

- Tag what matters: #idea #project

> Your notes. Your files. Your server.

📄 Daily note.md

📄 Ideas.md

📄 Second Brain.md

The foundation

Why Obsidian

Notes are plain Markdown files in a folder — no database, no lock-in
Local-first: works offline, on every platform, forever
[[Links]] + graph view turn notes into a network, not a pile
Huge plugin ecosystem — the one that matters tonight: Self-hosted LiveSync

The problem

One brain, many devices

Phone on the tram, laptop at work, PC at home — the vault must be everywhere
Official Obsidian Sync is great… but your notes live on someone else's cloud
Our rule at SolidAI: the source of truth stays on hardware we control
Answer: a $6/month VPS and two containers

Architecture

The whole thing fits in one diagram

Layer 1 · Sync

CouchDB + Self-hosted LiveSync

One CouchDB container behind HTTPS — that's the entire sync server
The LiveSync community plugin syncs every device in near-real-time
Phone note → CouchDB → server vault → laptop, in seconds
New device? Install plugin, point it at the URL, Fetch from remote. Done.
End-to-end encryption available if you want zero-trust hosting

Optional · Access anywhere

Obsidian in the browser — as a switch

Full desktop Obsidian (graph view included) streamed to any browser, running next to the data. Off by default; two words turn it on.

# "turn on obsidian" (I say it in Telegram, my agent runs it)
docker compose up -d obsidian   # → https://obsidian.██████.com

# "turn off obsidian" — sync never notices
docker compose stop obsidian

Costs ~1 GB RAM only while it runs. CouchDB and the webhook never blink.

Layer 2 · localAI

An AI that lives with your brain

Claude Code runs on the VPS, right next to the vault
I talk to it from Telegram — it manages the whole stack for me
- "turn on obsidian" · "check the backups" · "what did the team report today?"
It keeps its own persistent memory in Markdown too — agents need second brains as well
The key piece: agents don't just read the vault. They write to it.

The magic trick

Agents write into the vault via webhook

curl -X POST https://sync.██████.com/hook/report \
  -H "Authorization: Bearer $TOKEN" \
  -d '{"agente":"claude","titulo":"Nightly audit",
       "contenido":"Backups ✅ · SSL renews in 12 days"}'

A ~30 MB Bun service appends to per-agent daily notes: Equipo/<agent>/2026-07-30.md
It writes LiveSync-format documents straight into CouchDB…
…so every device gets the note instantly, even with the UI off
Cron jobs report health checks, backups and security scans into the vault every night

What it feels like

Capture on the tram. 📱
Think on the laptop. 💻
While agents file their reports
into the same brain — while you sleep. 😴

Scars · learn from ours

Gotchas we hit so you don't have to

Bytes ≠ string length. LiveSync doc sizes are UTF-8 bytes; using JS .length made notes with emojis show as "corrupted" on devices
Setup wizards flip your flags. The plugin's dialogs silently disabled syncOnStart — edit its config only while the container is stopped
Stale proxy configs haunt you. An old Traefik file claimed our domain and served 502s — clean up after experiments
Programmatic writes go through CouchDB, not the filesystem — files dropped in the vault folder only sync while the UI runs

Recipe

Build yours this weekend

1 Any small VPS + Docker + a domain
2 CouchDB container behind Traefik/Caddy with HTTPS
3 Obsidian + Self-hosted LiveSync on every device
4 Optional: linuxserver/obsidian for browser access, off by default
5 Optional: a tiny webhook so your AI/automations can write to the vault
6 Point a local agent (Claude Code, etc.) at the server and give it memory

Thanks!

Own your second brain.
Then give it hands.

Leonardo Rincón · SolidAI
Questions → let's talk. Slides: presentation.racielinsulation.com

Build a Second Brainwith Obsidian & localAI

Obsidian is a note-taking appfor your desktop and phone