Second Brain Link — build a second brain from your data exports: a private, local AI brain and digital twin
Second Brain · your digital twin
Destination reached
The whole road, in one connected brain.
Every source, person, and chapter you drove past — resolved, linked, and queryable. Opens in Obsidian and Claude Code. Runs 100% on your machine.
Free · open source (MIT) · your data never leaves your machine
Second Brain Studio
Browse and talk to your brain — right in the browser.
No setup, no plugins. Open your vault in a live workspace: explore how everything connects, read and edit notes, and ask an AI that reasons over the whole graph. It runs locally — your API keys and data never leave your machine. New: the graph renders as living tissue — and you can watch a question fire through it.
Interactive graph
A live, force-directed graph of every person, org, place and post. Filter by type or source, search, and click any node to open its note.
Talk to your brain
A built-in assistant — Claude, OpenAI, Gemini and more — that cites the notes it used. Bring your own key; calls go straight to the provider.
Read, edit & track
A full Markdown editor with live preview, wikilinks and backlinks, plus a computed dashboard of your network and clusters.
Second Brain Mobile · iOS & Android
Your twin in your pocket — built entirely on your phone.
A native mobile app that unpacks your exports and builds the brain on-device: no account, no cloud, nothing uploaded. Explore the knowledge graph and talk to your twin — with Apple Intelligence running on-device on iPhone, or your own AI keys stored in the phone's keychain.
Built on-device
Import your LinkedIn, Facebook, Instagram and Google exports on the phone — the full transform runs locally, and the brain lives in your pocket.
The graph in your hand
A native, buttery-smooth 3D graph of everyone you know and everything they connect to — search it, filter it, tap into any note.
Private by architecture
No account, no backend, zero telemetry. On-device AI on iPhone; on Android bring your own key — either way your data never leaves the device.
On the App Store and Google Play.
The Agent Skill · Claude Code & OpenAI Codex
The engine itself — install the skill, then just ask.
The product that powers everything: the open-source engine, packaged as a cross-model Agent Skill. Install it once in Claude Code or OpenAI Codex and your agent knows how to build, update and reason over second brains — locally, with zero network calls. No app required; your AI is the interface.
One skill, two runtimes
One shared engine, thin Claude Code and Codex packagings (the Agent Skills open standard). Prefer a terminal? It also runs as a plain CLI.
Self-adapting
It profiles any export, writes its own mapping rules when formats drift, and rescues files it doesn't recognize — nothing is lost.
Yours forever
MIT-licensed, dependency-free Python, zero network calls in the core. Read the code, fork it, add your own source adapters.
The same skill powers Studio's reseed and the mobile app's engine — install it in one step or browse the source on GitHub.
The problem
Your most valuable context is rotting in a zip file.
Everyone you know, every role you've held, every signal of what you want next — frozen in export archives no human reads and no AI can use. The reasoning engines arrived. The data to feed them is sitting there, unusable.
data/ ├── linkedin/ │ ├── Connections.csv 2,847 rows, no context │ ├── Positions.csv │ └── messages.csv never parsed ├── facebook-export.zip friends.json, 14 MB ├── instagram-export.zip followers_1.json └── takeout-20260514.zip contacts, maps, 2.1 GB ✕ four formats, zero links, same person 3×
vault/my-brain/ ├── Home.md entry point ├── 00-me/profile.md ├── 10-people/ │ └── Sam-Patel.md 1 note · 3 sources ├── 15-organizations/ ├── 40-career/timeline.md ├── 85-places/ └── 90-synthesis/ └── network-map.md who you actually know ✓ one graph — typed, linked, deduplicated
How it works
One prompt. About a minute.
- 01
Detect
Tell your agent to build your brain from a folder of exports. The skill catalogs every file it recognizes — CSV, JSON, Takeout — locally.
- 02
Resolve
The same person on three platforms becomes one identity. Names, handles, and employers are matched and merged.
- 03
Build
Every entity becomes a typed Markdown note with clean frontmatter and resolved wikilinks. No AI calls, no cost.
- 04
Open
Open the vault in Obsidian, or point Claude Code at it and give it a goal.
Self-adapting
Exports drift. The skill adapts itself.
Every platform changes its export format over time and across regions — a hardcoded converter breaks the moment that happens. This skill doesn't: it profiles your actual archive, adjusts its own mappings to your export's particularities, and proves nothing was left behind.
Profiles your actual export
Before building, it schema-maps every file and column it finds — locally, PII-safe — and flags anything it doesn't recognize instead of guessing.
Rewrites its own mappings
Sources are declarative JSON mappings, not hardcoded parsers. New field, renamed column, regional variant? The AI extends the mapping to fit your files — no code release needed.
Nothing lost, and it can prove it
Files no source claims are rescued by a universal harvester; every file is accounted for in _COVERAGE.md. If a build ever fails, a structured error report lets the AI fix the exact script and re-run — the self-heal loop.
Every fix ratchets the system: the adjusted mapping keeps working on your next export. How self-adapting works →
Agent-ready
Not notes. Structured data your agent can reason over.
Real Obsidian Properties
Typed frontmatter on every note — person, organization, place — with ISO dates and enums, not freeform text.
Wikilinks are edges
Every [[link]] resolves to a real note. Your agent traverses the graph the same way you click through it.
Layered vault
00-me → 10-people → 40-career → 90-synthesis. Stable paths an agent (or a script) can rely on.
In-vault CLAUDE.md
The vault ships with instructions for Claude Code and an Agent Skill — your agent knows how to use it on first open.
Identity resolution
The same person everywhere — resolved into one.
Sam Patel is a LinkedIn connection, a Facebook friend, and a Google contact. Most tools give you three orphan notes. You get one — enriched from every source.
What you can do
Don't search your life. Give your brain a goal.
Honest limit: your export is a snapshot — sharp on history, blind to this week. Re-export and update in place with --refresh — your edits are kept; hosted, scheduled sync lands with Cloud.
Where your brain lives
Obsidian + Claude Code by default. GBrain when you want it.
Obsidian vault
DefaultA real graph with native Properties. No plugins required — open Home.md and it works.
Claude Code & OpenAI Codex
DefaultShips as an Agent Skill plus an in-vault CLAUDE.md. Your agent knows the schema on first open.
GBrain
Optional--emit gbrain turns a company's exports into a Company Brain in the open GBrain format.
We don't reimplement search, synthesis, or serving — Obsidian, Claude, Codex, and GBrain do that. We do the part none of them do: turn export archives into a clean, identity-resolved brain.
Local-first
Privacy isn't a promise. It's the code.
Zero network calls in the core — your exports never leave your machine. The rules are enforced in source you can read.
PII never written
Third-party emails and phone numbers are stripped at parse time — they never reach disk.
Bodies never read
Message content is never parsed. Only a frequency and recency signal survives.
Sensitive files quarantined
Logins, receipts, and message archives are skipped by a hard-coded quarantine list.
Owner mode
Building your own brain? --full keeps everything — still 100% local.
This is the privacy policy, enforced in code. → View on GitHub
Get started
Install it, point your AI at your life.
Roadmap
A weekend script doesn't have a roadmap. This does.
LinkedIn → vault
Full local transform, Obsidian-native.
Multi-source
Facebook, Instagram, Google — one identity-resolved graph.
Cross-model + company
Claude + Codex, per-entity brains, GBrain emitter, JSON mappings.
24 sources
X, WhatsApp, GitHub, YouTube, Strava, Reddit, Spotify, TikTok + 12 company sources; --refresh updates.
Always-fresh
--refresh re-import shipped: update your brain in place from a newer archive, your edits kept. Hosted scheduled sync lands with Cloud.
Anatomy & activation
Cellular graph anatomy + spreading-activation retrieval, animated on real numbers. 25k-note vaults render fully.
The agentic ops layer
The brain that acts: meeting prep, drafting in your voice, reviving dormant relationships — and grounded search: web research that starts from your brain's context.
Local OSS core free forever. Done-for-you company onboarding and hosted sync are how it becomes a company.
Built in the open
Open source, by design.
MIT-licensed. This is why an incumbent can't build it: their business is locking your data in — ours is handing it back, working.
MIT-licensed and open from day one. Read the source, file an issue, or help shape v1.
★ Star on GitHubMake your data your advantage.
The second brain that starts full, not empty — a private AI brain built from the exports you already own.
MIT · local-first · Obsidian + Claude Code + OpenAI Codex · emits to GBrain.