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

* 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)

.github/workflows/ci.yml

@@ -103,7 +103,15 @@ jobs:
 
       - name: Build MCPB bundle (pdf-server)
         if: runner.os == 'Linux' && matrix.name == 'Linux x64'
-        run: npx -y @anthropic-ai/mcpb pack
+        run: node build-mcpb.mjs
+        working-directory: examples/pdf-server
+
+      - name: Smoke-test MCPB bundle starts
+        if: runner.os == 'Linux' && matrix.name == 'Linux x64'
+        run: |
+          unzip -q pdf-server.mcpb -d .mcpb-smoke
+          node .mcpb-smoke/dist/index.js --stdio < /dev/null 2>&1 | tee /tmp/mcpb-smoke.log
+          grep -q "Ready" /tmp/mcpb-smoke.log
         working-directory: examples/pdf-server
 
   e2e:

.github/workflows/npm-publish.yml

@@ -159,12 +159,8 @@ jobs:
           cache: npm
       - run: npm ci
 
-      - name: Build pdf-server
-        run: npm run build --workspace examples/pdf-server
-
-      - name: Pack MCPB bundle
-        run: npx -y @anthropic-ai/mcpb pack
-        working-directory: examples/pdf-server
+      - name: Build pdf-server + MCPB bundle
+        run: npm run build:mcpb --workspace examples/pdf-server
 
       - name: Upload MCPB to release
         run: gh release upload "${{ github.event.release.tag_name }}" examples/pdf-server/*.mcpb --clobber

.gitignore

@@ -16,3 +16,5 @@ __pycache__/
 
 # MCPB bundles (built artifacts)
 *.mcpb
+.mcpb-stage/
+.mcpb-smoke/

examples/pdf-server/build-mcpb.mjs

@@ -0,0 +1,56 @@
+#!/usr/bin/env node
+/**
+ * Build a self-contained .mcpb bundle for pdf-server.
+ *
+ * `mcpb pack` zips whatever is on disk; in this monorepo all runtime deps
+ * are hoisted to the root node_modules, so packing in-place produces a
+ * bundle with no pdfjs-dist/ajv/etc. that crashes in Claude Desktop.
+ *
+ * This script stages dist/ + manifest into a clean temp dir, runs a fresh
+ * non-workspace `npm install --omit=dev --omit=optional` (the polyfill in
+ * dist/pdfjs-polyfill.js makes @napi-rs/canvas's ~130MB of native binaries
+ * unnecessary), syncs the manifest version to package.json, then packs.
+ */
+
+import {
+  cpSync,
+  rmSync,
+  mkdirSync,
+  readFileSync,
+  writeFileSync,
+} from "node:fs";
+import { execSync } from "node:child_process";
+import { fileURLToPath } from "node:url";
+import path from "node:path";
+
+const here = path.dirname(fileURLToPath(import.meta.url));
+const stage = path.join(here, ".mcpb-stage");
+const out = path.join(here, "pdf-server.mcpb");
+
+const pkg = JSON.parse(readFileSync(path.join(here, "package.json"), "utf8"));
+const manifest = JSON.parse(
+  readFileSync(path.join(here, "manifest.json"), "utf8"),
+);
+manifest.version = pkg.version;
+
+rmSync(stage, { recursive: true, force: true });
+mkdirSync(stage);
+
+for (const f of ["dist", "icon.png", "README.md", ".mcpbignore"]) {
+  cpSync(path.join(here, f), path.join(stage, f), { recursive: true });
+}
+writeFileSync(
+  path.join(stage, "manifest.json"),
+  JSON.stringify(manifest, null, 2),
+);
+writeFileSync(path.join(stage, "package.json"), JSON.stringify(pkg, null, 2));
+
+const run = (cmd) => execSync(cmd, { cwd: stage, stdio: "inherit" });
+run(
+  "npm install --omit=dev --omit=optional --no-audit --no-fund --no-package-lock " +
+    "--registry=https://registry.npmjs.org/",
+);
+run(`npx -y @anthropic-ai/mcpb pack . ${JSON.stringify(out)}`);
+
+rmSync(stage, { recursive: true, force: true });
+console.log(`\n✅ ${path.relative(process.cwd(), out)}`);

examples/pdf-server/manifest.json

@@ -1,7 +1,7 @@
 {
   "manifest_version": "0.3",
   "name": "@modelcontextprotocol/server-pdf",
-  "display_name": "PDF (By Anthropic)",
+  "display_name": "pdf-viewer",
   "version": "1.0.1",
   "description": "Read and interact with PDF files using an interactive viewer with search, navigation, and text extraction",
   "author": {
@@ -34,8 +34,8 @@
       "description": "Display an interactive PDF viewer with search and navigation"
     },
     {
-      "name": "read_pdf_bytes",
-      "description": "Read a range of bytes from a PDF file (max 512KB per request)"
+      "name": "interact",
+      "description": "Interact with a PDF viewer: annotate, navigate, search, extract text/screenshots, fill forms"
     }
   ],
   "keywords": ["pdf", "documents", "viewer", "reading"],

examples/pdf-server/package.json

@@ -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",

examples/pdf-server/pdfjs-polyfill.ts

@@ -0,0 +1,26 @@
+/**
+ * Stub polyfills for pdfjs-dist's legacy build under Node.js.
+ *
+ * pdfjs-dist/legacy/build/pdf.mjs eagerly does `new DOMMatrix()` at module
+ * scope. Its own polyfill loads `@napi-rs/canvas` (an optionalDependency),
+ * but `npx` / fresh installs frequently miss the platform-native binary
+ * (npm optional-deps bug, see https://github.com/npm/cli/issues/4828),
+ * so the import crashes before our server code runs.
+ *
+ * The server only uses pdfjs for text/metadata/form-field extraction —
+ * never canvas rendering — so no-op stubs are sufficient and avoid
+ * shipping ~130MB of native binaries we don't need.
+ *
+ * MUST be a separate ESM module imported before pdfjs-dist (and kept
+ * `--external` in the bun bundle) so it executes before pdfjs's
+ * module-level initializer. Inlined body code would run too late
+ * because static imports are hoisted.
+ */
+
+/* eslint-disable @typescript-eslint/no-explicit-any */
+const g = globalThis as any;
+
+// Only stub if missing — let a real @napi-rs/canvas (or jsdom) win.
+g.DOMMatrix ??= class DOMMatrix {};
+g.ImageData ??= class ImageData {};
+g.Path2D ??= class Path2D {};

examples/pdf-server/server.ts

@@ -25,7 +25,10 @@ import {
   type CallToolResult,
   type ReadResourceResult,
 } from "@modelcontextprotocol/sdk/types.js";
-// Use the legacy build to avoid DOMMatrix dependency in Node.js
+// Stub DOMMatrix/ImageData/Path2D before pdfjs-dist loads — its legacy
+// build instantiates DOMMatrix at module scope and the @napi-rs/canvas
+// polyfill is unreliable under npx. See ./pdfjs-polyfill.ts for details.
+import "./pdfjs-polyfill.js";
 import {
   getDocument,
   VerbosityLevel,