0041. Element libraries and the built-in provider icon sets

Status: accepted (element-libraries change, 14 October 2026)

Context

The owner liked the icon picker and asked for what draw.io offers: libraries of ready-made elements for AWS, Google Cloud, Azure and Kubernetes, by category, to pick from a panel. The built-in pack was Tabler; provider icons had to be added to each project by hand, under the project’s own licence entries; the palette offered only the language’s kinds. The owner approved downloading the vendors’ official sets and @iconify-json/logos.

Decision

• Vendor sets converted once, kept in the repository. pnpm vendor:icons turns the vendors’ downloads into Iconify files in packages/assets/vendor/ with the vendor’s categories, a label per icon and info naming the version, the author, the licence and the vendor’s terms. Icons keep their geometry and colours; <style> rules are inlined, clip paths and filters dropped, editor metadata removed; icons the sanitiser still refuses are left out. Google Cloud’s icons take categories from a table kept beside the script, since the download has none.
• Terms travel with the sets. The packs of AWS, Azure and Google Cloud are marked as not freely redistributable, as project packs of provider icons already could be; the licence inventory, the extension’s and the playground’s notices repeat each set’s terms.
• Libraries are data. A library file lists elements by category (icon, label, optional kind). Every pack with categories is a library of its own; the built-in tech library curates the logos; projects add assets/libraries/*.json and plugins declare libraries under the icons permission.
• The panel creates through the language. A library element becomes a node (a box in free compositions) with the label and style <id> { icon "…" } on the next line: nothing new in the language, and the text stays the truth.
• Packs load lazily in the browser. The playground fetches a provider pack the first time a document or the panel needs it; the extension bundles them.

Alternatives considered

• Fetching the vendors’ sets at run time. Nothing a project uses is fetched (decision 0030); and the vendors’ URLs change every release.
• Only CC0 sets from npm. Clean, but uneven: AWS is well covered by the logos, Azure and Google Cloud are not, Kubernetes has only its mark.
• Provider shapes beyond a box with an icon. The language’s kinds and groups cover architecture diagrams; a group with an icon stands for a VPC or a cluster.

Consequences

• @meltemi/diagrams-assets grows by about 3 MB of JSON and depends on @iconify-json/logos (7.8 MB); the extension and the playground bundle them, the playground fetching on demand.
• A new vendor release is adopted by rerunning the script and reviewing the icons it leaves out.
• The icons added from the editor are listed in a Project library, assets/libraries/project.json, a category per pack (decision 0054).