PDF Viewer

When to Use

• Embedding contracts, invoices, or reports inline in a Blazor page without leaving the app
• Document preview surfaces where the browser's built-in viewer behaves inconsistently across platforms
• Read-only flows that benefit from page navigation, zoom, and full-text search (e.g. audit trails, e-signatures)
• Dashboards that surface generated PDF reports alongside live data
• Admin panels that need to display uploaded user documents with a controlled, branded UI

Self-hosting pdf.js

By default the viewer lazy-loads pdf.js + its worker from jsDelivr the first time a PdfViewer mounts. That's the right tradeoff for low-traffic apps and demos, but it doesn't work behind a strict CSP, on an air-gapped intranet, or in compliance scenarios where every third-party script call is a no-go.

The Lumeo CLI ships a one-shot installer that vendors pdf.js into wwwroot/lib/lumeo-vendor/ and wires up window.lumeoCdn so the runtime loads from your own origin instead of the CDN:

# 1. Install the Lumeo CLI as a global dotnet tool
$ dotnet tool install -g Lumeo.Cli

# 2. Vendor pdf.js into wwwroot/lib/lumeo-vendor/ and write the bootstrap
$ lumeo deps install --lib pdfjs --write-bootstrap

# 3. Include the bootstrap before _content/Lumeo.PdfViewer/js/* in index.html
#    <script src="js/lumeo-cdn-init.js"></script>

See CDN dependencies for the full list of self-hostable libraries and the window.lumeoCdn override surface. For more granular control (custom URL, integrity hash, alternative CDN) you can set window.lumeoCdn = { pdfJs: "/my/cdn/pdf.min.mjs", pdfJsWorker: "/my/cdn/pdf.worker.min.mjs" }; before the first PdfViewer mounts.