Add .mcpb Claude Desktop bundle with zero-config token handling

New scripts/build-mcpb.mjs packs a Claude Desktop extension bundle (scripts/mcpb-wrapper.mjs + manifest + icon) into dist-mcpb/tiletopia.mcpb. The wrapper reads the bearer token from %APPDATA% at launch and execs `npx -y mcp-remote`, so no secrets are baked in and Regenerate keeps working transparently. Run via `pnpm run build:mcpb`. McpPanel gets a "Download .mcpb" button linking to the releases page; the help-overlay tip and README MCP section both lead with the bundle install path and keep the .mcp.json shim recipe as the Claude Code fallback. Session-log entry in memory.md covers the design choices, especially why the wrapper-script approach beat the alternatives (user_config prompt would defeat one-click; baked-in token would be wrong for everyone else).
2026-05-26 17:31:34 +01:00 · 2026-05-26 17:31:34 +01:00 · b29233a012
commit b29233a012
parent 25aac634ab
9 changed files with 505 additions and 3 deletions
--- a/.gitignore
+++ b/.gitignore
@ -1,6 +1,7 @@
 # Node / build
 node_modules/
 dist/
+dist-mcpb/
 .svelte-kit/
 .pnpm-store/
 *.tsbuildinfo
--- a/README.md
+++ b/README.md
@ -114,9 +114,25 @@ The titlebar 🤖 button opens a small panel that starts an MCP (Model Context P
 - **Saved SSH passwords are never exposed** through the MCP surface.
 - **Bound to all interfaces** (`0.0.0.0`). The bearer token is the only auth — don't enable the server on an untrusted network.

-#### Claude Code setup (via `mcp-remote` stdio shim)
+#### Claude Desktop setup (one-click via `.mcpb` bundle — recommended)

-Claude Code's HTTP-MCP client currently tries OAuth discovery and ignores static `headers` auth (Anthropic [#17152](https://github.com/anthropics/claude-code/issues/17152), [#46879](https://github.com/anthropics/claude-code/issues/46879)). The [`mcp-remote`](https://www.npmjs.com/package/mcp-remote) stdio shim transparently proxies the HTTP endpoint with the bearer header attached, sidestepping the OAuth flow.
+The MCP panel has a **Download .mcpb** button that fetches a packaged Claude Desktop extension (an `.mcpb` file). Drag it into Claude Desktop's *Settings → Extensions* pane and Claude will auto-discover tiletopia — no config editing, no copy-pasting tokens.
+
+The bundle ships a tiny wrapper that reads your per-install bearer token straight from `%APPDATA%\com.megaproxy.tiletopia\mcp.json` at launch, so:
+
+- It carries **no secrets** — the same file works for every tiletopia install.
+- **Token regeneration** in the panel keeps working transparently; the next time Claude Desktop launches the extension, it'll pick up the new token.
+- Requires `npx` (Node 18+) on PATH because the wrapper still talks to tiletopia through `mcp-remote` (same reason as the manual recipe below).
+
+You can also rebuild the bundle from source:
+
+```sh
+pnpm run build:mcpb     # writes dist-mcpb/tiletopia.mcpb
+```
+
+#### Claude Code setup (via `mcp-remote` stdio shim — fallback / manual recipe)
+
+Claude Code (the terminal CLI) doesn't accept `.mcpb` bundles yet, and its HTTP-MCP client currently tries OAuth discovery and ignores static `headers` auth (Anthropic [#17152](https://github.com/anthropics/claude-code/issues/17152), [#46879](https://github.com/anthropics/claude-code/issues/46879)). The [`mcp-remote`](https://www.npmjs.com/package/mcp-remote) stdio shim transparently proxies the HTTP endpoint with the bearer header attached, sidestepping the OAuth flow.

 The panel's config snippet uses this shim by default — paste it into your project's `.mcp.json`:

--- a/memory.md
+++ b/memory.md
@ -106,6 +106,41 @@ The keyboard-shortcut table in README and the in-app help overlay used to be han

 **Verified:** ran twice, second run reports "already up to date" with empty `git diff`. `pnpm check` clean (tsc --noEmit, exit 0).

+### 2026-05-26 — `.mcpb` Claude Desktop bundle (zero-config token handling)
+
+Long-standing follow-up shipped. Build script + tiny Node wrapper produce `dist-mcpb/tiletopia.mcpb` — a one-click Claude Desktop install replacing the hand-paste of `.mcp.json`.
+
+**Key design choice — per-install token handling.** The `.mcpb` spec offers two ways to handle credentials: `user_config` prompts at install time (copy-paste), or bake them in (wrong). Both lose: copy-paste defeats the whole point of one-click, and token rotation (the Regenerate button) would silently invalidate any saved `user_config` value. Picked a **third option not in the spec docs**: bundle a tiny Node wrapper as `entry_point` that reads `%APPDATA%\com.megaproxy.tiletopia\mcp.json` at launch and execs `npx -y mcp-remote ...` with the live token. Zero secrets in the bundle → safe to publish on the releases page; works for any tiletopia install; transparently picks up the new token after Regenerate without the user re-doing anything.
+
+**Bundle shape (`scripts/build-mcpb.mjs`):**
+- `manifest.json` — `type: "node"`, `entry_point: "server/index.mjs"`, `mcp_config: { command: "node", args: ["${__dirname}/server/index.mjs"] }`, version mirrors `package.json`, icon points at the 128×128 brand PNG.
+- `server/index.mjs` — the wrapper. Reads `mcp.json`, validates port + token, spawns `npx -y mcp-remote http://127.0.0.1:<port>/mcp --allow-http --header "Authorization: Bearer <token>"` with `stdio: "inherit"`, forwards SIGINT/SIGTERM/SIGHUP to clean up the child on extension disable.
+- `icon.png` — copy of `src-tauri/icons/128x128.png`.
+
+**Build path.** `pnpm run build:mcpb` → `dist-mcpb/tiletopia.mcpb` (gitignored). Pure-Node store-only ZIP writer (~70 lines, no `archiver`/`jszip` devDep). Validated end-to-end with Python `zipfile`: 3 entries, valid CRCs, manifest parses. ~9 KB output.
+
+**Distribution.** The script is committed; the artifact isn't (regenerable). The intent is to attach `tiletopia.mcpb` to each Forgejo release alongside the NSIS installer — `scripts/release.sh` doesn't do this yet (follow-up). The new "Download .mcpb" button in `McpPanel` opens the releases page; once the artifact is up there, users grab it from there.
+
+**UI changes.**
+- `McpPanel.tsx`: new "Claude Desktop (one-click install)" field above the .mcp.json snippet with a "Download .mcpb" button (opens the releases URL via `plugin-opener`) and a brief hint explaining zero-config token handling + the regen script. Styled in `McpPanel.css` (`.mcp-mcpb-row`, `.mcp-mcpb-btn`, `.mcp-mcpb-hint`).
+- `McpPanel.css`: also added an explicit `.mcp-hint` style that was previously inheriting (used by both the token hint and the .mcpb hint).
+- `shortcuts.ts`: MCP tip now leads with the `.mcpb` install path; the mcp-remote shim is described as the fallback for Claude Code (the terminal CLI, which doesn't accept `.mcpb` yet).
+- `README.md`: same restructure under the MCP section — Claude Desktop install via `.mcpb` first, Claude Code via mcp-remote second.
+
+**Why no in-app file save dialog?** I considered bundling the `.mcpb` inside the Tauri NSIS as a Rust resource + exposing a `download_mcpb` Tauri command that opens a save dialog. Would let the panel button work fully in-app. Rejected because (a) it'd require Rust changes which I can't compile-check in WSL, (b) it duplicates what releases do for free, and (c) "Download .mcpb" landing on the releases page is the more discoverable distribution flow long-term.
+
+**Confirmed: bundle contains zero secrets.** Scanned both `manifest.json` and `server/index.mjs` for `Bearer ey`, `token=`, `secret`, `password`, `api_key` — all clean. The wrapper reads the token from `%APPDATA%` at runtime on the *user's* machine; nothing is ever baked in.
+
+**`pnpm check` clean, vitest 72/72 passing.**
+
+Open follow-ups specific to this session:
+
+- **Wire `.mcpb` into the release.** `scripts/release.sh` currently uploads only the NSIS installer; it should also run `node scripts/build-mcpb.mjs` and attach the resulting `dist-mcpb/tiletopia.mcpb` to the Forgejo release. Two lines + one `tea releases create --asset` flag. Until that's done, the "Download .mcpb" button lands on a releases page where the asset doesn't exist yet for old tags.
+- **Direct in-app save flow.** If we ever want fully-offline install (no roundtrip through the web), add a Rust-side `download_mcpb` command that returns the bundled bytes + use `@tauri-apps/plugin-dialog` save() in the panel. Not blocking — current flow is sufficient and matches how Tauri apps usually distribute extension files.
+- **Pre-flight on the wrapper.** Could detect missing `npx` / Node 18+ and emit a more directed message. Currently we just let `spawn` fail with whatever Node says. The "make sure Node 18+ is installed and `npx` is on PATH" line in the error path is the band-aid.
+- **`.mcpb` for Claude Code (CLI).** Claude Code doesn't accept `.mcpb` bundles yet — Anthropic may add it. When they do, the same bundle should Just Work since the wrapper is platform-agnostic re: which Claude is calling it.
+- **Bundle compatibility field.** Manifest declares `platforms: ["win32"]` and `runtimes: { node: ">=18.0.0" }`. The wrapper has a hard `%APPDATA%` requirement so this is correct, but if anyone ever wants macOS / Linux tiletopia support, the wrapper needs a portable config-path lookup.
+
 ### 2026-05-26 — Hard-deny: PowerShell patterns + label list de-duplicated

 Mirrors the POSIX hard-deny rules with their Windows/PowerShell equivalents. Four new patterns:
--- a/package.json
+++ b/package.json
@ -10,6 +10,7 @@
    "test": "vitest run",
    "test:watch": "vitest",
    "check": "tsc --noEmit",
+    "build:mcpb": "node scripts/build-mcpb.mjs",
    "gen:readme": "node scripts/gen-readme-shortcuts.mjs",
    "tauri": "tauri"
  },
--- a/scripts/build-mcpb.mjs
+++ b/scripts/build-mcpb.mjs
@ -0,0 +1,259 @@
+#!/usr/bin/env node
+// build-mcpb.mjs — package tiletopia's Claude Desktop MCP bundle.
+//
+// Produces dist-mcpb/tiletopia.mcpb — an .mcpb (MCP Bundle, the format
+// formerly known as DXT) zip containing:
+//   manifest.json          → declares a node-type server pointing at the wrapper
+//   server/index.mjs       → the wrapper script that reads %APPDATA% and
+//                            execs `npx -y mcp-remote ...` (see mcpb-wrapper.mjs)
+//   icon.png               → 128×128 brand icon
+//
+// Usage:
+//   pnpm run build:mcpb
+// or
+//   node scripts/build-mcpb.mjs
+//
+// Output:
+//   dist-mcpb/tiletopia.mcpb   — drag-and-drop this into Claude Desktop's
+//                                Extensions panel to install.
+//
+// Design notes:
+//   - The bundle bakes in NO secrets. The bearer token + port are read at
+//     runtime from %APPDATA%\com.megaproxy.tiletopia\mcp.json on the user's
+//     own machine. Each install of tiletopia generates its own token; the
+//     bundle is the same for everyone.
+//   - We write the zip ourselves (store-only, no compression) to avoid a
+//     devDep on archiver/jszip/etc. The MCPB spec is just a regular zip;
+//     three small files = trivial.
+//   - The manifest's `version` mirrors package.json so the panel UI can show
+//     "Bundle v0.2.3 — matches running app".
+
+import { readFile, writeFile, mkdir, stat } from "node:fs/promises";
+import { existsSync } from "node:fs";
+import { dirname, join, resolve } from "node:path";
+import { fileURLToPath } from "node:url";
+import { deflateRawSync, crc32 } from "node:zlib";
+
+const HERE = dirname(fileURLToPath(import.meta.url));
+const REPO_ROOT = resolve(HERE, "..");
+const PKG_PATH = join(REPO_ROOT, "package.json");
+const WRAPPER_PATH = join(HERE, "mcpb-wrapper.mjs");
+const ICON_PATH = join(REPO_ROOT, "src-tauri", "icons", "128x128.png");
+const OUT_DIR = join(REPO_ROOT, "dist-mcpb");
+const OUT_PATH = join(OUT_DIR, "tiletopia.mcpb");
+
+// ----------------------------------------------------------------------------
+// Read inputs
+// ----------------------------------------------------------------------------
+
+if (!existsSync(WRAPPER_PATH)) {
+  console.error(`missing wrapper: ${WRAPPER_PATH}`);
+  process.exit(1);
+}
+if (!existsSync(ICON_PATH)) {
+  console.error(`missing icon: ${ICON_PATH}`);
+  process.exit(1);
+}
+
+const pkg = JSON.parse(await readFile(PKG_PATH, "utf8"));
+const wrapperSrc = await readFile(WRAPPER_PATH);
+const iconBytes = await readFile(ICON_PATH);
+
+// ----------------------------------------------------------------------------
+// Manifest
+//
+// Schema reference: https://github.com/modelcontextprotocol/mcpb/blob/main/MANIFEST.md
+//
+// type=node + entry_point pointing at server/index.mjs + mcp_config.command
+// = "node" matches Claude Desktop's expectations. We avoid a `user_config`
+// block on purpose — the wrapper reads the token from %APPDATA% so the user
+// doesn't have to copy-paste it at install time.
+// ----------------------------------------------------------------------------
+
+const manifest = {
+  manifest_version: "0.3",
+  name: "tiletopia",
+  display_name: "tiletopia (workspace driver)",
+  version: pkg.version,
+  description:
+    "Drive your tiletopia workspace from Claude Desktop — inspect panes, " +
+    "read scrollback, reshape the layout, and (with policy approval) send " +
+    "commands.",
+  long_description:
+    "tiletopia is a Windows tiling terminal manager for WSL. This bundle " +
+    "lets Claude Desktop connect to a running tiletopia process on the same " +
+    "machine via its embedded MCP server. The bundle reads the per-install " +
+    "bearer token and port from %APPDATA%\\com.megaproxy.tiletopia\\mcp.json " +
+    "at launch, so you don't need to paste any credentials during install. " +
+    "Start the MCP server once from tiletopia's 🤖 panel (Server: ON), then " +
+    "drop this bundle into Claude Desktop and it will connect automatically. " +
+    "All write operations (spawn, write keystrokes, reshape) are gated by " +
+    "the per-pane allow-list and the user-editable policy inside tiletopia.",
+  author: {
+    name: "megaproxy",
+    url: "https://git.rdx4.com/megaproxy/tiletopia",
+  },
+  repository: {
+    type: "git",
+    url: "https://git.rdx4.com/megaproxy/tiletopia.git",
+  },
+  homepage: "https://git.rdx4.com/megaproxy/tiletopia",
+  documentation: "https://git.rdx4.com/megaproxy/tiletopia#mcp-server-claude-can-drive-the-workspace",
+  support: "https://git.rdx4.com/megaproxy/tiletopia/issues",
+  icon: "icon.png",
+  server: {
+    type: "node",
+    entry_point: "server/index.mjs",
+    mcp_config: {
+      command: "node",
+      args: ["${__dirname}/server/index.mjs"],
+    },
+  },
+  keywords: ["tiletopia", "wsl", "terminal", "mcp", "claude"],
+  license: "Proprietary",
+  compatibility: {
+    // Claude Desktop runtime requirements — the bundle launches node, which
+    // shells out to npx mcp-remote; both need Node 18+ on PATH.
+    platforms: ["win32"],
+    runtimes: {
+      node: ">=18.0.0",
+    },
+  },
+};
+
+const manifestBytes = Buffer.from(JSON.stringify(manifest, null, 2), "utf8");
+
+// ----------------------------------------------------------------------------
+// Build the .mcpb zip
+//
+// The MCPB spec is a plain ZIP file. We're writing three small files, so a
+// pure-Node store-only writer is simplest. Avoids adding archiver as a
+// devDep. Format reference: APPNOTE.TXT 6.3.4 sections 4.3 (local file
+// header), 4.4 (data descriptor), 4.5 (central directory).
+// ----------------------------------------------------------------------------
+
+const SIG_LFH = 0x04034b50;
+const SIG_CDH = 0x02014b50;
+const SIG_EOCD = 0x06054b50;
+
+function dosTimeDate(date) {
+  // DOS time/date format (2-second resolution; epoch 1980-01-01).
+  const yr = Math.max(date.getFullYear(), 1980) - 1980;
+  const time =
+    ((date.getHours() & 0x1f) << 11) |
+    ((date.getMinutes() & 0x3f) << 5) |
+    ((Math.floor(date.getSeconds() / 2)) & 0x1f);
+  const dt =
+    ((yr & 0x7f) << 9) |
+    (((date.getMonth() + 1) & 0x0f) << 5) |
+    (date.getDate() & 0x1f);
+  return { time, date: dt };
+}
+
+function buildZip(entries) {
+  const now = dosTimeDate(new Date());
+  const chunks = [];
+  const centralDir = [];
+  let offset = 0;
+
+  for (const { name, data } of entries) {
+    const nameBuf = Buffer.from(name, "utf8");
+    const crc = crc32(data); // store-only — uncompressed crc == compressed crc
+    const size = data.length;
+
+    // Local file header (4.3.7)
+    const lfh = Buffer.alloc(30);
+    lfh.writeUInt32LE(SIG_LFH, 0);
+    lfh.writeUInt16LE(20, 4); // version needed (2.0)
+    lfh.writeUInt16LE(0, 6); // general purpose bit flag
+    lfh.writeUInt16LE(0, 8); // compression: store
+    lfh.writeUInt16LE(now.time, 10);
+    lfh.writeUInt16LE(now.date, 12);
+    lfh.writeUInt32LE(crc, 14);
+    lfh.writeUInt32LE(size, 18); // compressed size (== size for store)
+    lfh.writeUInt32LE(size, 22); // uncompressed size
+    lfh.writeUInt16LE(nameBuf.length, 26);
+    lfh.writeUInt16LE(0, 28); // extra field length
+    chunks.push(lfh, nameBuf, data);
+
+    // Central directory header (4.4.7)
+    const cdh = Buffer.alloc(46);
+    cdh.writeUInt32LE(SIG_CDH, 0);
+    cdh.writeUInt16LE(20, 4); // version made by
+    cdh.writeUInt16LE(20, 6); // version needed
+    cdh.writeUInt16LE(0, 8); // gp flag
+    cdh.writeUInt16LE(0, 10); // compression
+    cdh.writeUInt16LE(now.time, 12);
+    cdh.writeUInt16LE(now.date, 14);
+    cdh.writeUInt32LE(crc, 16);
+    cdh.writeUInt32LE(size, 20); // compressed size
+    cdh.writeUInt32LE(size, 24); // uncompressed
+    cdh.writeUInt16LE(nameBuf.length, 28);
+    cdh.writeUInt16LE(0, 30); // extra len
+    cdh.writeUInt16LE(0, 32); // comment len
+    cdh.writeUInt16LE(0, 34); // disk number
+    cdh.writeUInt16LE(0, 36); // internal attrs
+    cdh.writeUInt32LE(0, 38); // external attrs
+    cdh.writeUInt32LE(offset, 42); // local header offset
+    centralDir.push(cdh, nameBuf);
+
+    offset += lfh.length + nameBuf.length + data.length;
+  }
+
+  const cdStart = offset;
+  for (const buf of centralDir) {
+    chunks.push(buf);
+    offset += buf.length;
+  }
+  const cdSize = offset - cdStart;
+
+  // End of central directory record (4.5)
+  const eocd = Buffer.alloc(22);
+  eocd.writeUInt32LE(SIG_EOCD, 0);
+  eocd.writeUInt16LE(0, 4); // disk number
+  eocd.writeUInt16LE(0, 6); // start disk
+  eocd.writeUInt16LE(entries.length, 8); // entries on this disk
+  eocd.writeUInt16LE(entries.length, 10); // total entries
+  eocd.writeUInt32LE(cdSize, 12);
+  eocd.writeUInt32LE(cdStart, 16);
+  eocd.writeUInt16LE(0, 20); // comment length
+  chunks.push(eocd);
+
+  // Silence the "unused on store path" lint trip; deflateRawSync stays
+  // imported so a future maintainer who wants to add compression doesn't
+  // have to re-figure out the right symbol.
+  void deflateRawSync;
+
+  return Buffer.concat(chunks);
+}
+
+const entries = [
+  { name: "manifest.json", data: manifestBytes },
+  { name: "server/index.mjs", data: wrapperSrc },
+  { name: "icon.png", data: iconBytes },
+];
+
+const zipBytes = buildZip(entries);
+
+await mkdir(OUT_DIR, { recursive: true });
+await writeFile(OUT_PATH, zipBytes);
+
+const sizeKB = (zipBytes.length / 1024).toFixed(1);
+console.log(`wrote ${OUT_PATH} (${sizeKB} KB, ${entries.length} entries)`);
+for (const e of entries) {
+  console.log(`  ${e.name.padEnd(20)} ${e.data.length} bytes`);
+}
+console.log(
+  `manifest version ${manifest.version} (mirrors package.json); ` +
+    "to install, drag the .mcpb file into Claude Desktop's Extensions panel.",
+);
+
+// Touch stat() so any "wrote nothing" CI bug surfaces here, not at the user's
+// next install.
+const written = await stat(OUT_PATH);
+if (written.size !== zipBytes.length) {
+  console.error(
+    `size mismatch: wrote ${zipBytes.length} bytes, file is ${written.size}`,
+  );
+  process.exit(1);
+}
--- a/scripts/mcpb-wrapper.mjs
+++ b/scripts/mcpb-wrapper.mjs
@ -0,0 +1,110 @@
+#!/usr/bin/env node
+// tiletopia .mcpb wrapper — entry_point for the bundled MCP server.
+//
+// What this is: a thin stdio shim Claude Desktop launches when the user
+// installs `tiletopia.mcpb`. It reads the per-install MCP server settings
+// (port + bearer token) that the running tiletopia app persisted to
+// %APPDATA%\com.megaproxy.tiletopia\mcp.json, then execs `npx -y mcp-remote`
+// with the right URL + Authorization header. Claude talks stdio to us; we
+// proxy through mcp-remote, which talks HTTP to the tiletopia process.
+//
+// Why a wrapper (not just static args in the manifest):
+//   - The bearer token is per-install — generated at first server start, also
+//     rotated whenever the user clicks "Regenerate" in the MCP panel. We
+//     can't bake it into the bundle (that'd be wrong for every other user)
+//     and we don't want to make the user paste it into a user_config prompt
+//     at install time. Reading it from %APPDATA% at launch makes the whole
+//     thing zero-config and survives token rotation transparently.
+//   - The port may also drift (if the saved port is taken, tiletopia falls
+//     back to an OS-picked one and re-persists). Reading at launch keeps us
+//     correct across that too.
+//
+// Failure modes & messages: every error we emit goes to stderr so the user
+// sees it in Claude Desktop's extension log. We deliberately do NOT swallow
+// or transform mcp-remote's own output beyond piping it.
+
+import { spawn } from "node:child_process";
+import { readFileSync, existsSync } from "node:fs";
+import { join } from "node:path";
+
+const APPDATA = process.env.APPDATA;
+if (!APPDATA) {
+  console.error(
+    "[tiletopia-mcpb] %APPDATA% is unset — this bundle only runs on Windows.",
+  );
+  process.exit(2);
+}
+
+const CFG_PATH = join(APPDATA, "com.megaproxy.tiletopia", "mcp.json");
+if (!existsSync(CFG_PATH)) {
+  console.error(
+    `[tiletopia-mcpb] config not found at ${CFG_PATH}. ` +
+      "Launch tiletopia, open the 🤖 MCP panel, and click Server: ON at least " +
+      "once so the port + token get persisted, then retry.",
+  );
+  process.exit(3);
+}
+
+let cfg;
+try {
+  cfg = JSON.parse(readFileSync(CFG_PATH, "utf8"));
+} catch (e) {
+  console.error(`[tiletopia-mcpb] failed to read/parse ${CFG_PATH}: ${e.message}`);
+  process.exit(4);
+}
+
+const port = Number(cfg.port);
+const token = String(cfg.token ?? "");
+if (!Number.isInteger(port) || port <= 0 || port > 65535 || !token) {
+  console.error(
+    `[tiletopia-mcpb] ${CFG_PATH} is missing a valid port or token. ` +
+      "Toggle the MCP server off and on in the tiletopia panel to regenerate it.",
+  );
+  process.exit(5);
+}
+
+const url = `http://127.0.0.1:${port}/mcp`;
+
+// `npx.cmd` on Windows is the actual launcher; bare `npx` is a shim that
+// node spawns from PATH and that's also fine. spawn() with shell:true ensures
+// PATHEXT resolution picks up the .cmd correctly.
+const child = spawn(
+  "npx",
+  [
+    "-y",
+    "mcp-remote",
+    url,
+    "--allow-http",
+    "--header",
+    `Authorization: Bearer ${token}`,
+  ],
+  {
+    stdio: "inherit",
+    shell: true,
+  },
+);
+
+child.on("error", (e) => {
+  console.error(
+    `[tiletopia-mcpb] failed to spawn npx: ${e.message}. ` +
+      "Make sure Node.js 18+ is installed and `npx` is on PATH.",
+  );
+  process.exit(6);
+});
+
+child.on("exit", (code, signal) => {
+  if (signal) process.kill(process.pid, signal);
+  else process.exit(code ?? 0);
+});
+
+// Forward terminate signals to the child so Claude Desktop's "disable
+// extension" cleans up the mcp-remote subprocess.
+for (const sig of ["SIGINT", "SIGTERM", "SIGHUP"]) {
+  process.on(sig, () => {
+    try {
+      child.kill(sig);
+    } catch {
+      /* child may already be gone */
+    }
+  });
+}
--- a/src/components/McpPanel.css
+++ b/src/components/McpPanel.css
@ -187,6 +187,55 @@
  color: #ccd;
 }

+/* Inline small-print under inputs — small, muted, tight line-height. Used by
+ * the token hint and the .mcpb install hint. */
+.mcp-hint {
+  margin: 4px 0 0;
+  color: #888;
+  font-size: 11px;
+  line-height: 1.4;
+}
+.mcp-hint code {
+  background: #0c0c0c;
+  padding: 1px 4px;
+  border-radius: 2px;
+  font-family: inherit;
+  color: #aac;
+}
+
+/* ---- Claude Desktop .mcpb install row ----------------------------------- */
+
+.mcp-mcpb-row {
+  display: flex;
+  align-items: flex-start;
+  gap: 12px;
+}
+
+.mcp-mcpb-btn {
+  font: inherit;
+  font-family: inherit;
+  font-size: 11px;
+  font-weight: 600;
+  background: #1a2a3a;
+  color: #cce6ff;
+  border: 1px solid #2a4a6a;
+  border-radius: 3px;
+  padding: 6px 14px;
+  cursor: pointer;
+  flex-shrink: 0;
+  white-space: nowrap;
+}
+.mcp-mcpb-btn:hover {
+  background: #2a4a6a;
+  color: #e0f0ff;
+  border-color: #4488cc;
+}
+
+.mcp-mcpb-hint {
+  flex: 1 1 auto;
+  margin: 0;
+}
+
 .mcp-snippet {
  font: inherit;
  font-family: inherit;
--- a/src/components/McpPanel.tsx
+++ b/src/components/McpPanel.tsx
@ -2,12 +2,18 @@ import { useEffect, useState, useCallback } from "react";
 import {
  writeText as clipboardWriteText,
 } from "@tauri-apps/plugin-clipboard-manager";
+import { openUrl } from "@tauri-apps/plugin-opener";
 import type { McpStatus, McpAuditEntry } from "../ipc";
 import AuditTab from "./AuditTab";
 import PolicyTab from "./PolicyTab";
 import ErrorBoundary from "./ErrorBoundary";
 import "./McpPanel.css";

+// URL of the GitHub-style releases page where each tagged build attaches the
+// prebuilt `.mcpb` bundle (sibling to the NSIS installer). Source bundle is
+// regeneratable via `pnpm run build:mcpb`.
+const MCPB_RELEASES_URL = "https://git.rdx4.com/megaproxy/tiletopia/releases";
+
 interface McpPanelProps {
  status: McpStatus;
  onStart: () => Promise<void>;
@ -196,6 +202,31 @@ export default function McpPanel({
                    </p>
                  </div>

+                  <div className="mcp-field">
+                    <label>Claude Desktop (one-click install)</label>
+                    <div className="mcp-mcpb-row">
+                      <button
+                        className="mcp-mcpb-btn"
+                        onClick={() => {
+                          void openUrl(MCPB_RELEASES_URL).catch((e) =>
+                            console.warn("open releases page failed:", e),
+                          );
+                        }}
+                      >
+                        Download .mcpb
+                      </button>
+                      <p className="mcp-hint mcp-mcpb-hint">
+                        Grab <code>tiletopia.mcpb</code> from the releases
+                        page, then drag it into Claude Desktop's{" "}
+                        <em>Settings → Extensions</em>. The bundle reads your
+                        bearer token from <code>%APPDATA%</code> at launch —
+                        zero copy-paste, and token regeneration above keeps
+                        working transparently. (Bundle is regeneratable from
+                        source via <code>pnpm run build:mcpb</code>.)
+                      </p>
+                    </div>
+                  </div>
+
                  <div className="mcp-field">
                    <label>Claude Code config snippet (.mcp.json)</label>
                    <pre className="mcp-snippet">
--- a/src/lib/shortcuts.ts
+++ b/src/lib/shortcuts.ts
@ -110,6 +110,6 @@ export const TIPS: TipSpec[] = [
  },
  {
    title: "MCP server (let Claude drive the workspace)",
-    body: "Titlebar 🤖 opens the MCP control panel — start the server and paste the snippet into your Claude Code .mcp.json. The snippet uses npx mcp-remote as a stdio shim because Claude Code's HTTP-MCP client ignores static bearer auth and tries OAuth instead; the shim proxies the HTTP endpoint with the bearer baked in. URL + token persist across restarts; Regenerate the token in the panel if it leaks. Default-deny per pane: toggle 🤖 on each pane's toolbar to expose it to MCP. Read-only in v1 (no spawn or write yet).",
+    body: "Titlebar 🤖 opens the MCP control panel. Start the server, then for Claude Desktop click 'Download .mcpb' and drag the file into Settings → Extensions — zero-config because the bundle reads your bearer token from %APPDATA% at launch (no copy-paste, survives token rotation). For Claude Code (terminal CLI) use the fallback snippet in the panel: it wires npx mcp-remote as a stdio shim because Claude Code's HTTP-MCP client ignores static bearer auth and tries OAuth instead. URL + token persist across restarts; Regenerate the token in the panel if it leaks. Default-deny per pane: toggle 🤖 on each pane's toolbar to expose it to MCP.",
  },
 ];