---
type: ApplicationType
title: library (application type)
description: An importable public API with no runtime entrypoint of its own. Existing layout vocabulary value (byte-preserved).
tags: [application-type, catalog, rfc-114, library]
timestamp: 2026-07-03T00:00:00Z
---

# library (application type)

The **library** type: an importable public API consumed by other programs, with
no runtime entrypoint of its own. Existing value in the layout vocabulary
(`LAYOUT_PROJECT_TYPES`), byte-preserved on the wire.

## Entry (structured — the judgment-carrying-catalog schema)

```yaml
kind: application-type
id: library
question: application-type
features:
  - id: importable-api-no-entrypoint
    signal: "an importable public API (packaged module surface) with no runtime entrypoint of its own"
    observed_via: manifest-field
lineage:
  tradition: "software libraries"
  exemplars: ["PyPI libraries", "npm packages"]
  reference: "layout_record.LAYOUT_PROJECT_TYPES (RFC #100; wire value byte-preserved)"
examples:
  - "layout_bootstrap's library classification for entrypoint-less packaged trees (RFC #100)"
```
