Second Brain: a project vault for you and your AI agent

A ready-made Obsidian structure that turns your notes into a second brain an AI agent can read and write. Download it, open it as a vault, fill it with your project, and your agent will work from your context instead of guessing.

Built by Paul Sikorsky. The thinking behind it: sikorsky.design/second-brain.

Why

Models got good. The bottleneck now isn't the model, it's how much context it has about you and your work. Without context, an agent reaches for an average answer off the internet, or invents one. A structured vault in plain text closes that gap: the context lives in files, the agent reads them, nothing gets distorted or lost.

Who it's for

Founders, indie makers, designers, and product people who run a project and want an agent that actually knows it. This is the project / product template. A personal-life version is a separate thing, don't mix the two.

What's inside

00. Dashboard               your daily entry point
00. Vault Rules & Guide     how the vault works, for you and the agent
CLAUDE.md                   the agent's condensed rules + routing table

01. Inbox/                  fast capture
02. Strategy/ (Goals/)      vision, roadmap, north-star, OKRs
03. Team/ (Operations/)     people, cadence, tool stack, hiring
04. Business/               pricing, finance, legal, partnerships
05. Releases/               launch plans and retros
06. Brand/                  voice, identity, logo, type
07. Product/                positioning, specs, mechanics
08. Design/                 design system, UX, components
09. Engineering/            architecture, integrations, tech decisions
10. Marketing/              channels, copy, campaigns
11. Decisions/              ADRs with rationale
12. Research/               PMF, RAT, interviews, synthesis
13. Companies/              competitors, partners, vendors
14. Meetings/               syncs, ad-hoc, interviews
15. Customer Ops/           support procedures, FAQ, refunds
16. Meta/                   templates, attachments, bases
17. Archive/

Every domain folder ships with an index note that doubles as documentation. It tells you (and the agent) what belongs there. Six note templates (Note, Decision, Meeting, Person, Release, Post) live in 16. Meta/Templates/.

Install (no terminal)

1. Download this repo as a ZIP (green Code button → Download ZIP) and unzip it. Rename the folder to your project if you like.
2. Open Obsidian → Open folder as vault → select the folder.
3. Enable plugins. Turn on the built-in Templates core plugin (Settings → Core plugins) and set its template folder to 16. Meta/Templates. Install the Dataview community plugin (Settings → Community plugins), the indexes need it. Add Obsidian Git too if you'll sync via GitHub.
4. Pin 00. Dashboard and 00. Vault Rules & Guide. Read the Rules once.

Prefer Git? git clone the repo and open it as a vault instead. Same result, with version history.

Requirements

• Obsidian (free).
• Dataview (community plugin) required. The indexes are live Dataview queries; without it they render as plain code blocks.
• Templates (core plugin, built in) for the note templates. Enable it and point it at 16. Meta/Templates.
• Obsidian Git (community plugin) optional, for GitHub sync.

Connect your agent

The vault is plain text, so any agent with filesystem access can use it.

• Drop a Filesystem MCP server pointed at this folder into your agent (e.g. Claude Desktop), so it can read and write the notes.
• The agent reads CLAUDE.md at the root, its rules and routing table. Keep it in sync with the human Rules.
• Two skills ship in Skills/ vault-keeper (recall, promote, link, gap-check) and draft-in-voice (write copy that sounds like the project). Point your agent's skills directory at them. See Skills/README.md.

Full walkthrough: sikorsky.design/second-brain.

License

CC BY 4.0 use it freely, including commercially, adapt it however you like; just credit Paul Sikorsky and link back. See LICENSE.

Made by Paul Sikorsky while building Baselife, a journal and life calendar for living with more intention. More on life design, mindful productivity, and building in public: t.me/initsrightplace.