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fix(pdf-server): npx DOMMatrix crash + broken MCPB bundle (#584)

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* fix(pdf-server): stub DOMMatrix/ImageData/Path2D for npx without @napi-rs/canvas

pdfjs-dist/legacy/build/pdf.mjs does `new DOMMatrix()` at module scope.
Its own polyfill loads @napi-rs/canvas (an optionalDependency), but npx
frequently misses the platform-native binary (npm/cli#4828), so the
server crashed on `npx @modelcontextprotocol/server-pdf --stdio`:

    ReferenceError: DOMMatrix is not defined
        at pdfjs-dist/legacy/build/pdf.mjs:17078

The server only uses pdfjs for text/metadata/form-field extraction —
never canvas rendering — so no-op stubs suffice and avoid shipping
~130MB of native binaries.

The polyfill is a separate ESM module kept --external in the bun bundle
so it executes before pdfjs's hoisted static import; inlined body code
would run too late.

Broken since 1.3.0 (#506). Thanks to Bryan Thompson for the analysis
and fix shape from the npm-to-mcpb pipeline.

* fix(pdf-server): MCPB bundle missing runtime deps + display_name with spaces

`mcpb pack` zips whatever is on disk; in this monorepo all runtime deps
are hoisted to root node_modules, so the published .mcpb shipped without
pdfjs-dist/ajv/express/etc. and crashed on import in Claude Desktop.

build-mcpb.mjs stages dist/ + manifest into a clean temp dir, runs a
non-workspace `npm install --omit=dev --omit=optional` (the new
DOMMatrix polyfill makes @napi-rs/canvas's ~130MB of native binaries
unnecessary), syncs manifest.version to package.json, then packs.
Result: 12.3MB / 38.8MB unpacked, full MCP handshake + tools/list pass.

Also rename display_name "PDF (By Anthropic)" → "pdf-viewer" — spaces
in display_name break MCP App UI rendering for MCPBs in Claude Desktop.

CI now smoke-tests the extracted bundle starts (`dist/index.js --stdio`
prints "Ready") so a deps-less bundle can't ship again.

* fix(pdf-server): list interact in MCPB manifest tools (was stale since #491)
This commit is contained in:
Olivier Chafik 2026-04-02 04:16:33 +01:00 • committed by GitHub
commit 04fed524a9
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1 changed files with 106 additions and 14 deletions
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5
examples/pdf-server/package.json
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@ -14,14 +14,15 @@
"dist"
],
"scripts": {
"build": "tsc --noEmit && cross-env INPUT=mcp-app.html vite build && tsc -p tsconfig.server.json && bun build server.ts --outdir dist --target node --external pdfjs-dist && bun build main.ts --outfile dist/index.js --target node --external \"./server.js\" --external pdfjs-dist --banner \"#!/usr/bin/env node\"",
"build": "tsc --noEmit && cross-env INPUT=mcp-app.html vite build && tsc -p tsconfig.server.json && bun build pdfjs-polyfill.ts --outdir dist --target node && bun build server.ts --outdir dist --target node --external pdfjs-dist --external \"./pdfjs-polyfill.js\" && bun build main.ts --outfile dist/index.js --target node --external \"./server.js\" --external pdfjs-dist --banner \"#!/usr/bin/env node\"",
"watch": "cross-env INPUT=mcp-app.html vite build --watch",
"serve": "bun --watch main.ts --enable-interact",
"serve:stdio": "bun main.ts --stdio",
"start": "cross-env NODE_ENV=development npm run build && npm run serve",
"start:stdio": "cross-env NODE_ENV=development npm run build 1>&2 && npm run serve:stdio",
"dev": "cross-env NODE_ENV=development concurrently \"npm run watch\" \"npm run serve\"",
"prepublishOnly": "npm run build"
"prepublishOnly": "npm run build",
"build:mcpb": "npm run build && node build-mcpb.mjs"
},
"dependencies": {
"@modelcontextprotocol/ext-apps": "^1.0.0",