Wiki front matter: the typed edges

foundations
graph
A few lines of YAML at the top of each page carry the relationships that turn linked markdown into something an agent can reason over.
Author

Chris Sweet

Published

May 6, 2026

What front matter is. If you have used a static-site generator or a modern note app, you have already met front matter: the small block of YAML metadata fenced by --- at the top of a file. Jekyll, Hugo, Obsidian, and Quarto (which renders this page) all use it to attach structured fields, a title, a date, tags, to an otherwise free-text document.

Making the links between pages typed and machine-readable is also established prior art, most cleanly in Semantic MediaWiki: instead of a plain link, you annotate it with a property ([[author::Ada Lovelace]]), and the property name classifies the relationship, turning a wiki into a queryable database. The idea is that a link should carry what kind of link it is, not just point somewhere.

How this wiki uses it. Every page opens with front matter. Two fields are required, type: (what kind of page) and up: (its parent). The rest are optional typed edges: extends:, supports:, criticizes:, requires:, related:. Each names a relationship to another page. These particular edge names are this schema’s choice, not the general pattern; related: is an honest catch-all, while extends:, supports:, and criticizes: are stronger claims used only where the material makes them.

Here is the top of a real page:

---
type: synthesis
up: "[[Retrieval-Vision]]"
extends: "[[Distribution-vs-Pattern-Retrieval]]"
criticizes: "[[Heavy-Content-Graphs]]"
related: ["[[Lightweight-Structural-Graphs]]"]
---

That block alone tells you the page is a synthesis, sits under the retrieval vision, builds on one page, disputes another, and is loosely tied to a third, all before you read a word of its prose. A human skims it; an agent parses it.

The payoff is that this metadata reifies to a graph. Reify just means turning an implicit relationship into an explicit data record, so every typed edge becomes an RDF triple, a subject-predicate-object fact. The criticizes: line above becomes the triple this-page criticizes Heavy-Content-Graphs, which a database can query. The same annotation a human reads is a structure software can walk. The discipline is calibrated to content: an experimental wiki keeps placement strict and treats related: as a catch-all; a review wiki over a fixed corpus can afford aggressive typed edges. Forcing crisp edges onto provisional work manufactures a confidence the material does not have.

Sources