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2.11.0: standard-fonts JSON imports missing "type: json" import attribute, breaks under plain Node ESM #156
Description
Since 2.10.0/2.11.0 vendored @cantoo/standard-fonts, importing @cantoo/pdf-lib's ESM build under plain Node (not a bundler) throws:
Module ".../@cantoo/pdf-lib/es/packages/standard-fonts/Courier-Bold.compressed.json" needs an import attribute of "type: json"
Bundlers like Vite tolerate a bare import x from './foo.json', but Node's ESM loader requires with { type: 'json' } (or an equivalent import attribute) as of Node 22. This breaks any consumer that imports pdf-lib during a Node-executed SSR/prerender step rather than through a bundler — e.g. Astro's static-route generation, which runs built page modules directly under Node.
Repro:
node --input-type=module -e "import '@cantoo/pdf-lib'"
on 2.11.0 with Node 22.x.
2.9.1 didn't hit this since @cantoo/standard-fonts wasn't vendored as raw JSON imports yet.
Reacted by electrovir
Activity
Sharcoux commentedon Sep 15, 2026
Can you check if 2.11.1 solves it?
shlomsh commentedon Sep 15, 2026
Yes, 2.11.1 fixes it. Thanks for the quick turnaround.
Checked on Node 24.13. The repro from the report now imports, embeds Helvetica and saves. 2.11.0 still throws
ERR_IMPORT_ATTRIBUTE_MISSINGin the same sandbox, so it's the version and not the environment. The Astro build that first hit this is green on 2.11.1 too.I also diffed the two npm tarballs to see what actually changed. It's the 14
*.compressed.jsonimports ines/packages/standard-fonts/Font.jsplusall-encodings.compressed.jsoninEncoding.js, all nowwith { type: 'json' }, and no other JSON import is left underes/. That matches the failure exactly:cjs/goes throughrequire()and never needed the attribute,dist/inlines the JSON so it has no.jsonreferences, and the ESM entry was the only path Node resolves file by file. Small fix, right scope.One thing worth knowing:
with { ... }is the finalized syntax (Node 20.10+ and 22+). Node 18 only understoodassert { ... }, but 18 is EOL, so that seems like the right trade.