Licensing

petal-elements is licensed under the Apache License 2.0, like the projects it builds on. This page records how we handle attribution and third-party material.

Upstream sources

Link to “Upstream sources”

Source	License	Copyright	Used for
material-components/material-web	Apache-2.0	Google LLC	The whole code base, including the Material Design web tokens in `tokens/versions/`
androidx/androidx (Jetpack Compose Material 3 `tokens/*Tokens.kt`, pinned commit in `tokens/sources.json`)	Apache-2.0	The Android Open Source Project	`tokens/dtcg/compose/` (cross-check) and the expressive springs in `tokens/css/sys.css`; see tokens.md

Sources added later (for example material-color-utilities) are added to this table and to NOTICE in the same change that first brings their material into the repository.

File headers

Link to “File headers”

Files from upstream keep their original @license / SPDX header.
Upstream files we change get one extra line under the SPDX line (Apache-2.0 section 4(b)):
```
Modified for petal-elements; modifications Copyright <year> Saki. See NOTICE.
```
scripts/rebrand.ts adds it automatically to the files it changes. Add it by hand when editing other upstream files. Files without comments (JSON, images) are covered by NOTICE and the git history.
New files use:
```
Copyright <year> Saki
SPDX-License-Identifier: Apache-2.0
```
Generated files must say where they come from: source repository, pinned commit, that they are generated, and the original copyright and license notice of the source. The token scripts do this: CSS files in a comment header, DTCG JSON files in the root $description and $extensions["dev.petal-elements"].

Names and content

Link to “Names and content”

Package, tag and brand names do not contain material or md-. CSS custom properties keep the --md-* names so existing themes keep working.
We do not copy text or images from m3.material.io. Values come from the token sources above.

Dependencies

Link to “Dependencies”

npm run check:licenses reads every installed package (after npm ci) and fails on licenses outside the allowlist in scripts/check-licenses.ts. Runtime dependencies must be permissive (MIT, ISC, BSD, Apache-2.0, 0BSD, W3C). A few more licenses are allowed for build and test tools only. CI runs this check.

Third-party asset audit (2026-10-08)

Link to “Third-party asset audit (2026-10-08)”

Audit of fonts and images in docs/ and catalog/ at the start of the project.

Asset	Finding	Action
`catalog/site/fonts/google-sans/regular.woff2`, `mono.woff2`	Google Sans and Google Sans Mono. No license file in the repository, and we could not confirm an open font license for these files.	Removed, with their `@font-face` rules. The catalog falls back to Roboto / system fonts.
`docs/../images/what-is-material.webp`	Sample app screenshot with photos of people. Source unknown.	Removed.
`docs/theming/../images/theming.webp`	Collage with Google product logos and stock photos. Source unknown.	Removed.
`docs/theming/../images/color-scheme-light.webp`, `color-scheme-dark.webp`, `token-types.webp`	Diagrams in Material Design site style. Source not recorded.	Replaced (2026-10-09) by figures rendered from `tokens/css/sys.css` and our components (`docs/theming/figures/`).
`docs/../images/material-web.gif`	Animation of upstream components.	Kept; not used by our README.
`docs/components/../images/**`	Screenshots of the upstream components; the hero images were phone mockups with stock photos.	Replaced (2026-10-09) by images rendered from our own components with `npm run docs:images` (`scripts/docs-../images/`). Animated GIFs became still images or were dropped.
Google logos in docs and demos (four-color plus in the branded FAB examples, "G" logo in the chip demo), Lit / Polymer / Angular logos in the list docs, `placekitten.com` images	Third-party brand marks and an external image service.	Replaced (2026-10-09) with our own flower logo, Material Symbols icons and inline placeholder images.
`catalog/site/../images/favicon.svg`, `catalog/src/svg/material-design-logo.ts`	Upstream catalog icon and the Material Design logo in the catalog's top bar.	Replaced (2026-10-09) with our own flower logo (`catalog/src/svg/logo.ts`).
Google Sans / Google Sans Mono in catalog CSS	Font names left after the font files were removed.	Removed (2026-10-09); the catalog uses Roboto / system fonts.
Web fonts loaded from fonts.googleapis.com (Roboto, Open Sans, Google Sans, Material Symbols) in demos, the catalog and the landing page	Loaded at runtime, not redistributed.	No action. We do not bundle fonts.
Site bundles (`landing/`, `catalog/`, published to GitHub Pages)	Bundles npm packages such as lit (BSD-3-Clause), playground-elements (BSD-3-Clause) and @material/material-color-utilities (Apache-2.0).	esbuild writes their license comments to `*.LEGAL.txt` files next to the bundles, which are published with the site.
`@fontsource/roboto` (OFL-1.1), `material-symbols` (Apache-2.0)	Dev dependencies used to render test screenshots and doc images.	Not in the npm package. Only the rendered images are committed.

The removed files still exist in the upstream git history, which this repository keeps in full.