add claude desktop extension

.github/workflows/build.yml

@@ -17,3 +17,5 @@ jobs:
       - run: bun install
 
       - run: bun run build
+
+      - run: bun ./scripts/validate-mcpb-artifact.mjs

.gitignore

@@ -15,5 +15,7 @@ node_modules
 tmp/
 temp/
 
-# Built assets
-*.mcpb
+# Built assets (keep committed MCPB; un-ignore dist/ first so children can match)
+**/dist/**
+!**/dist/
+!**/dist/paper.mcpb

README.md

@@ -25,3 +25,13 @@ Are we missing one, you have feedback for us, or just want to chat? Join us on o
 ```sh
 /plugin install paper-desktop@paper
 ```
+
+## Claude Desktop
+
+Pack the config-only MCPB extension, then open or drag `claude-extensions/paper-desktop/dist/paper.mcpb` into Claude Desktop → Extensions:
+
+```sh
+bun run pack:mcpb
+```
+
+Requires Paper Desktop installed and opened once (so `~/.paper/bin/paper` exists). See [`claude-extensions/paper-desktop`](claude-extensions/paper-desktop).

claude-extensions/paper-desktop/README.md

@@ -0,0 +1 @@
+../../plugins/paper-desktop/README.md

claude-extensions/paper-desktop/assets

@@ -0,0 +1 @@
+../../plugins/paper-desktop/assets

claude-extensions/paper-desktop/manifest.json

@@ -0,0 +1,53 @@
+{
+  "$schema": "https://raw.githubusercontent.com/anthropics/mcpb/main/schemas/mcpb-manifest-v0.4.schema.json",
+  "manifest_version": "0.4",
+  "name": "paper",
+  "display_name": "Paper",
+  "version": "0.1.0",
+  "description": "Design on a canvas that Claude can read and write to — built on web standards.",
+  "author": {
+    "name": "Paper",
+    "email": "team@paper.design",
+    "url": "https://paper.design"
+  },
+  "homepage": "https://paper.design",
+  "documentation": "https://paper.design/docs/mcp",
+  "support": "mailto:team@paper.design",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/paper-design/agent-plugins"
+  },
+  "license": "MIT",
+  "privacy_policies": ["https://paper.design/privacy"],
+  "icon": "assets/logo@512w.png",
+  "screenshots": [
+    "assets/barley-layout.png",
+    "assets/barley-feedback.png",
+    "assets/barley-responsive-frames.png"
+  ],
+  "keywords": [
+    "paper",
+    "design",
+    "ui",
+    "canvas",
+    "html",
+    "css",
+    "design-to-code",
+    "code-to-design",
+    "mcp",
+    "design-system"
+  ],
+  "server": {
+    "type": "binary",
+    "entry_point": "${HOME}/.paper/bin/paper",
+    "mcp_config": {
+      "command": "${HOME}/.paper/bin/paper",
+      "args": ["mcp"]
+    }
+  },
+  "compatibility": {
+    "claude_desktop": ">=0.1.0",
+    "platforms": ["darwin", "win32", "linux"]
+  },
+  "tools_generated": true
+}

claude-extensions/paper-desktop/package.json

@@ -0,0 +1,8 @@
+{
+  "name": "@paper/claude-desktop-mcpb",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "pack": "bun ./scripts/pack.ts"
+  }
+}

claude-extensions/paper-desktop/scripts/pack.ts

@@ -0,0 +1,101 @@
+#!/usr/bin/env bun
+/**
+ * Pack a config-only MCPB (zip with manifest.json at archive root).
+ *
+ * Injects README.md as long_description at pack time — the source
+ * manifest.json is left unchanged.
+ *
+ * Bundles icon/screenshot paths referenced by the built manifest (resolving
+ * symlinks into the archive).
+ *
+ * Uses a plain zip instead of `mcpb pack` because the binary entry_point is an
+ * external `${HOME}/.paper/bin/paper` path installed by Paper Desktop — not a
+ * file inside the bundle.
+ */
+import {
+  chmod,
+  cp,
+  mkdir,
+  readdir,
+  rm,
+  stat,
+  utimes,
+  writeFile,
+} from "node:fs/promises";
+import { dirname, join } from "node:path";
+import { fileURLToPath } from "node:url";
+import { $ } from "bun";
+import { buildMcpbManifest } from "../../../scripts/mcpb-manifest.mjs";
+
+/** DOS-era zip epoch — fixed so rebuilds are bit-identical across runs. */
+const ZIP_EPOCH = new Date(Date.UTC(1980, 0, 1, 0, 0, 0));
+/** Fixed Unix modes so Info-ZIP external attributes ignore umask / cp defaults. */
+const FILE_MODE = 0o644;
+const DIR_MODE = 0o755;
+
+async function normalizeStaging(dir: string) {
+  await chmod(dir, DIR_MODE);
+  await utimes(dir, ZIP_EPOCH, ZIP_EPOCH);
+  for (const name of await readdir(dir)) {
+    const path = join(dir, name);
+    if ((await stat(path)).isDirectory()) {
+      await normalizeStaging(path);
+    } else {
+      await chmod(path, FILE_MODE);
+      await utimes(path, ZIP_EPOCH, ZIP_EPOCH);
+    }
+  }
+}
+
+const extensionDir = join(dirname(fileURLToPath(import.meta.url)), "..");
+const repoRoot = join(extensionDir, "../..");
+const distDir = join(extensionDir, "dist");
+const stageDir = join(distDir, "stage");
+const outFile = join(distDir, "paper.mcpb");
+const builtManifestPath = join(stageDir, "manifest.json");
+
+const { manifest, readmeLabel } = buildMcpbManifest(extensionDir, {
+  root: repoRoot,
+});
+
+const assetPaths = [
+  ...(typeof manifest.icon === "string" ? [manifest.icon] : []),
+  ...(Array.isArray(manifest.screenshots) ? manifest.screenshots : []),
+];
+
+await rm(distDir, { recursive: true, force: true });
+await mkdir(stageDir, { recursive: true });
+await writeFile(builtManifestPath, `${JSON.stringify(manifest, null, 2)}\n`);
+
+for (const rel of assetPaths) {
+  if (typeof rel !== "string" || rel.includes("..") || rel.startsWith("/")) {
+    console.error(`Refusing to pack unsafe asset path: ${rel}`);
+    process.exit(1);
+  }
+  const src = join(extensionDir, rel);
+  const dest = join(stageDir, rel);
+  await mkdir(dirname(dest), { recursive: true });
+  await cp(src, dest);
+}
+
+await normalizeStaging(stageDir);
+
+// TZ=UTC so DOS timestamps in the zip are timezone-independent (CI is UTC).
+const result = await $`zip -r -X ${outFile} manifest.json ${assetPaths}`
+  .cwd(stageDir)
+  .env({ ...process.env, TZ: "UTC" })
+  .nothrow();
+
+if (result.exitCode !== 0) {
+  console.error(result.stderr.toString() || result.stdout.toString());
+  process.exit(result.exitCode ?? 1);
+}
+
+// Keep a copy of the built manifest next to the .mcpb for inspection
+await cp(builtManifestPath, join(distDir, "manifest.json"));
+await rm(stageDir, { recursive: true, force: true });
+
+const listing = await $`unzip -l ${outFile}`.text();
+console.log(listing.trimEnd());
+console.log(`\nInjected long_description from ${readmeLabel}`);
+console.log(`Wrote ${outFile}`);

package.json

@@ -3,9 +3,12 @@
   "type": "module",
   "private": true,
   "scripts": {
-    "build": "bun ./scripts/validate-cursor-schema.mjs && bun ./scripts/validate-cursor-structure.mjs"
+    "build": "bun ./scripts/validate-cursor-schema.mjs && bun ./scripts/validate-cursor-structure.mjs && bun ./scripts/validate-mcpb.mjs && bun run pack:mcpb",
+    "pack:mcpb": "bun ./claude-extensions/paper-desktop/scripts/pack.ts",
+    "test": "bun run build"
   },
   "devDependencies": {
+    "@anthropic-ai/mcpb": "^2.1.2",
     "@types/bun": "latest",
     "ajv": "^8.18.0",
     "ajv-formats": "^3.0.1"