# externals

**How a repository records what it depends on, and finds out when it changes.**

- [Externals](.loom/published/externals.md) — the convention

**Built on [bedrock](https://git.hypertheory-labs.dev/loom/bedrock)'s sibling
facets**, whose three open choices we answer in
[our usages of `annotating`](.loom/externals/git.hypertheory-labs.dev/loom/annotating/annotating.usages.md).

*And `annotating` is here as an external of ours — **fetched, locked, annotated**
— which is the convention describing itself using itself. **If that had not
worked, the convention would be wrong**, and it is the cheapest test available.*

> **The first copy was written by hand.** *You cannot fetch-and-annotate before
> the thing that says how exists. **Self-hosting is a test, not a
> derivation.***