# Files as Graph Database

A plain directory of markdown files with wikilinks satisfies the structural requirements of a graph database: nodes (files), edges (links), and optional labels (folders, frontmatter tags). You don't need a graph store to query a graph — you need a graph.

The mapping is literal:

- **Node** = one markdown file, identified by its filename
- **Edge** = a wikilink `[[other-file]]` inside the file's body
- **Node properties** = YAML frontmatter
- **Edge type / label** = context around the link, or dedicated frontmatter fields like `parent:` or `sources:`
- **Index / taxonomy** = folder structure

What you give up compared to a real graph database: no indexed edge traversal, no query language, no ACID guarantees, no multi-hop joins in constant time. What you gain: every tool on your machine already reads it. Grep is a query engine. Git is version control. Obsidian is a visualizer. An LLM with file access is a natural-language query interface.

The approach scales further than expected. [[filesystem-is-graph-database]] reports ~52k files maintained this way. The reason it holds up is that most PKM queries aren't graph queries in the Cypher sense — they're "find everything related to X and show me the content." Ripgrep handles that in milliseconds. Actual multi-hop traversal is rare; when it matters, an LLM doing a bounded search through linked files is usually good enough.

The key design choice is making the graph *legible* to tools that don't know it's a graph. Filenames must be unique so wikilinks resolve unambiguously. Folders should be shallow enough that link-following, not directory-walking, is the primary navigation pattern. Frontmatter should be consistent so it can be parsed without per-file special cases.

This is the underlying bet behind the [[llm-wiki-pattern]] and behind this Second Brain itself. It also connects to [[obsidian]] at the convention level — Obsidian happens to treat files exactly this way, which is why vaults port cleanly between Obsidian and pure-CLI workflows. The same shape carries through to publication: a [[digital-garden]] published with [[quartz]] preserves nodes, edges, and frontmatter without any translation step.