> ## Documentation Index
> Fetch the complete documentation index at: https://docs.9thprotocol.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Vault

> A folder of linked markdown that 9p navigates instead of re-reading your codebase.

A vault is a folder of markdown notes linked with `[[wiki links]]`. 9p reads the
index, follows links to what's relevant, and writes back what it learns. It's an
Obsidian vault if you point Obsidian at it — but Obsidian is optional. The
structure is what matters, not the app.

## Setup

```bash theme={null}
9p init          # choose "vault"
```

Creates the scaffold and records the path in `.9p/config.json`:

```
vault/
  INDEX.md        master map — everything reachable from here
  jobs/           reusable procedures the agent follows step by step
  decisions/      what was decided and why
  daily/          one note per working day
  projects/       one folder per project, master note named after the folder
  graph/          generated codebase maps (9p map)
```

## Mapping the codebase

```bash theme={null}
9p map
```

Explores the project and writes concise wiki notes into `graph/` — an index plus
one note per module, each linking to related notes. Re-run it to refresh; it
updates notes in place rather than duplicating.

This routes on `economy` bias deliberately: it's bulk read-and-summarise across
a whole repo.

## The index-note pattern

The pattern that makes this work: **every folder has a master note named after
the folder**, wiki-linked to everything inside it.

```markdown vault/jobs/release/release.md theme={null}
# Release

1. Confirm CI is green on `main`
2. Follow [[changelog]] to write release notes
3. Run the steps in [[deploy-steps]]
4. Announce per [[announce-template]]
```

9p reads one note, follows the links, and arrives fully briefed. You don't have
to tell it which files to read.

## Decisions

The highest-value notes are the ones git can't reconstruct — *why* something is
the way it is:

```markdown vault/decisions/why-no-orm.md theme={null}
# Why we don't use an ORM

Decided 2026-03-14. Query shapes are join-heavy and we kept fighting the query
planner. Rejected: Prisma (migration story), Drizzle (fine, but the win didn't
justify the rewrite). Affects [[db-layer]], [[repository-pattern]].
```

Months later, "why was this decided?" has an answer.

## Daily notes

Ask 9p to log at the end of a session:

```
9p ❯ write today's daily note: what we finished, what's next, what's blocked
```

Put a short index at the top of each daily note. Future sessions scan indexes
instead of reading every note in full.

## Anti-bloat

Worth stating in your [`9P.md`](/memory):

```markdown theme={null}
Vault rules:
- Append to an existing note; only create a new note when genuinely necessary
- Every new note must be linked from its folder's master note
```

Without a rule like that you accumulate hundreds of near-duplicate notes, and a
sprawling vault is worse than none — the agent trusts stale notes over the code.

<Note>
  Point Obsidian at the folder if you want the graph view. It's a good way for
  *you* to see the shape of the knowledge; 9p reads the markdown either way.
</Note>