electron-builder.config.mjs

/**
 * electron-builder configuration for the Agent Canvas desktop app.
 *
 * `directories.app: 'electron'` tells electron-builder to use electron/package.json
 * as the app manifest (with `"main": "main.mjs"`). This sidesteps the root
 * package.json's `"main": "./dist/index.cjs"` without any afterPack patching.
 *
 * NODE_MODULES NOTE:
 *
 *   Even with zero `dependencies` in electron/package.json, electron-builder's
 *   "search for node modules" routine walks UP from directories.app looking
 *   for the first node_modules in scope. It runs `npm list --json` in the
 *   project root, gets the full hoisted tree (~342 dirs, ~600 MB: Vite,
 *   React, Monaco, HeroUI, etc.), and copies all of it into the packaged
 *   app at Resources/app/node_modules/.
 *
 *   Almost none of those packages are imported at desktop runtime — main.mjs
 *   and the launcher (dev-with-automation.mjs) use only Node built-ins. The
 *   exception is the two child-process servers: static-server.mjs imports
 *   `sirv` and ingress.mjs (via proxy-utils.mjs) imports `httpxy`. Node
 *   resolves those bare specifiers by walking UP from the script's own path,
 *   so an app tested from dist-electron/ inside a repo checkout accidentally
 *   resolves them against the repo's node_modules and works — while the same
 *   app in /Applications crashes both servers with ERR_MODULE_NOT_FOUND and
 *   the splash times out waiting for port 8000. We can't disable the search
 *   from the config (it's hardcoded in app-builder-lib), and creating an
 *   empty electron/node_modules/ doesn't help because `npm list` from the
 *   project root still reports the full hoisted tree.
 *
 *   The fix is the `afterPack` hook below: after electron-builder has
 *   finished copying files, we rm -rf the bundled Resources/app/node_modules/
 *   directory, then copy back the dependency closure of RUNTIME_PACKAGES
 *   (~200 KB). The build wastes a few seconds copying files we immediately
 *   delete, but the final artifact is correctly tiny (~10 MB vs ~600 MB).
 *
 * Packaged app layout (Resources/app/ = electron/ contents):
 *   main.mjs        ← Electron entry point
 *   loading.html    ← loading splash
 *   package.json    ← {"main":"main.mjs"} (from electron/package.json)
 *   scripts/        ← backend scripts
 *   node_modules/   ← runtime closure of RUNTIME_PACKAGES (restored by afterPack)
 *   config/         ← defaults.json
 *   build/          ← static frontend (npm run build:app output)
 *
 * The bundled uv binary (resources/bin/) lands in <Resources>/bin/ via
 * extraResources so Electron can inject it into PATH on startup.
 *
 * The bundled Node.js distribution (resources/node/) lands in
 * <Resources>/node/ via extraResources — except for its root-level
 * node_modules (npm itself), which electron-builder refuses to copy and the
 * afterPack hook restores; see restoreBundledNodeNpm below.
 *
 * Electron prepends its bin dir to PATH at startup so backend scripts (`node
 * scripts/ingress.mjs` etc.) and stdio MCP servers spawned via `npx -y …`
 * (Slack, GitHub, Figma, etc.) can find a working node/npm/npx — the OS gives
 * a Finder-launched .app a minimal PATH (/usr/bin:/bin) that has none of those.
 */

import { cp, rm } from "node:fs/promises";
import { existsSync, readFileSync, readdirSync, statSync } from "node:fs";
import { dirname, join, relative } from "node:path";
import { fileURLToPath } from "node:url";

// npm packages the packaged app's child-process scripts import at runtime:
//   scripts/static-server.mjs  → sirv
//   scripts/proxy-utils.mjs    → httpxy   (imported by ingress.mjs)
// Their dependency closure is copied back into Resources/app/node_modules
// after the strip below. If a spawned script gains a new bare import, add
// the package here — a missing one crashes that service in the installed
// app with ERR_MODULE_NOT_FOUND (invisible under Finder, where stdout goes
// to /dev/null) and the splash times out waiting for port 8000.
const RUNTIME_PACKAGES = ["sirv", "httpxy"];

const repoRoot = dirname(fileURLToPath(import.meta.url));

// Root package.json is the single source of truth for the app version
// (release-please bumps it). electron/package.json is a minimal manifest
// stub pinned at 1.0.0 — `extraMetadata` below overrides its version at
// pack time so artifact names and app.getVersion() carry the released
// version instead.
const rootPackageJson = JSON.parse(
  readFileSync(join(repoRoot, "package.json"), "utf8"),
);

/**
 * Resolve the packaged app's Resources directory.
 *
 * On macOS it lives inside the `.app` bundle; on Linux/Windows it's a flat
 * `resources/` subdirectory. We resolve both shapes from `context.appOutDir`
 * + the productFilename.
 */
function packagedResourcesDir(context) {
  const platform = context.electronPlatformName;
  const productFilename = context.packager.appInfo.productFilename;
  return platform === "darwin" || platform === "mas"
    ? join(context.appOutDir, `${productFilename}.app`, "Contents", "Resources")
    : join(context.appOutDir, "resources");
}

/**
 * afterPack entry point. Invoked by electron-builder once per platform target
 * after the unpacked directory has been populated but before installer-format
 * packaging (DMG, NSIS, deb).
 */
async function afterPack(context) {
  await stripBundledNodeModules(context);
  await restoreBundledNodeNpm(context);
}

/**
 * Strip the auto-bundled node_modules from the packaged app, then restore
 * the small runtime closure of RUNTIME_PACKAGES.
 *
 * See the NODE_MODULES NOTE in the file header for the why.
 */
async function stripBundledNodeModules(context) {
  const appDir = join(packagedResourcesDir(context), "app");

  const nm = join(appDir, "node_modules");
  if (existsSync(nm)) {
    // Best-effort size report so the log line shows what we saved. Skip if
    // walking the tree fails for any reason — the rm below is what matters.
    let sizeMb = null;
    try {
      sizeMb = Math.round(getDirSizeBytes(nm) / (1024 * 1024));
    } catch {}

    await rm(nm, { recursive: true, force: true });

    const rel = relative(process.cwd(), nm);
    const human = sizeMb != null ? ` (~${sizeMb} MB)` : "";
    // eslint-disable-next-line no-console -- electron-builder build log
    console.log(
      `[electron-builder] stripped bundled node_modules${human}: ${rel}`,
    );
  }

  await restoreRuntimeNodeModules(appDir);
}

/**
 * Copy the dependency closure of RUNTIME_PACKAGES from the repo's
 * node_modules into the packaged app's Resources/app/node_modules so the
 * spawned `node scripts/…` servers can resolve their bare imports outside
 * a repo checkout (see RUNTIME_PACKAGES above).
 *
 * Resolution is deliberately simple: every package (and every transitive
 * `dependencies` entry) is looked up at the repo root's flat npm tree, and
 * a miss throws so the build fails loudly instead of shipping a DMG whose
 * ingress/static-server crash on launch.
 */
async function restoreRuntimeNodeModules(appDir) {
  const rootNodeModules = join(repoRoot, "node_modules");

  // name → source dir, walking `dependencies` breadth-first.
  const packages = new Map();
  const queue = [...RUNTIME_PACKAGES];
  while (queue.length) {
    const name = queue.shift();
    if (packages.has(name)) continue;
    const srcDir = join(rootNodeModules, ...name.split("/"));
    const manifestPath = join(srcDir, "package.json");
    if (!existsSync(manifestPath)) {
      throw new Error(
        `[electron-builder] runtime package "${name}" not found in ` +
          `${rootNodeModules} — run npm install and rebuild`,
      );
    }
    packages.set(name, srcDir);
    const manifest = JSON.parse(readFileSync(manifestPath, "utf8"));
    queue.push(...Object.keys(manifest.dependencies ?? {}));
  }

  let totalBytes = 0;
  for (const [name, srcDir] of packages) {
    const destDir = join(appDir, "node_modules", ...name.split("/"));
    await cp(srcDir, destDir, { recursive: true });
    totalBytes += getDirSizeBytes(destDir);
  }

  // eslint-disable-next-line no-console -- electron-builder build log
  console.log(
    `[electron-builder] restored runtime node_modules ` +
      `(${[...packages.keys()].join(", ")}; ~${Math.round(totalBytes / 1024)} KB)`,
  );
}

/**
 * Restore the bundled Node distribution's root-level `node_modules` (npm
 * itself), which electron-builder silently refuses to copy, then verify the
 * packed result.
 *
 * WHY THIS IS NEEDED — app-builder-lib's copy filter drops a `node_modules`
 * directory sitting at the ROOT of a `from` dir, before any `filter` pattern
 * is consulted (packages/app-builder-lib/src/util/filter.ts):
 *
 *     // filter the root node_modules, but not a subnode_modules
 *     if (relative === "node_modules") {
 *       return false
 *     }
 *
 * That check is reached for extraResources too — `copyFiles()` builds the
 * copy filter with the same `createFilter()`. Our extraResources entry copies
 * `resources/node/` → `<Resources>/node/`, and the Windows Node zip puts npm
 * at `<root>/node_modules/npm`, i.e. exactly `node_modules` relative to the
 * copy root. So it is skipped, and no `filter` value can opt back in.
 *
 * POSIX tarballs put npm at `<root>/lib/node_modules/npm`, which is not the
 * root entry and copies fine — which is why this only ever broke Windows and
 * went unnoticed on macOS.
 *
 * Symptom when it goes wrong: `<Resources>/node/` ships a working `node.exe`
 * next to `npm.cmd` / `npx.cmd` shims that exec
 * `%~dp0\node_modules\npm\bin\npx-cli.js` — a file that isn't there. Every
 * `npx -y <pkg>` spawn (stdio MCP servers, ACP servers) then dies with
 * MODULE_NOT_FOUND, and because injectBundledNode() PREPENDS this directory
 * to PATH it also shadows the user's own working npm installation.
 */
async function restoreBundledNodeNpm(context) {
  const isWin = context.electronPlatformName === "win32";
  const nodeDir = join(packagedResourcesDir(context), "node");

  // No bundled Node at all — `npm run download-node` was skipped. That is a
  // different (and already loudly reported) situation; main.mjs warns at
  // startup. Don't turn it into a build failure here.
  if (!existsSync(nodeDir)) return;

  const srcNodeModules = join(repoRoot, "resources", "node", "node_modules");
  const destNodeModules = join(nodeDir, "node_modules");
  if (!existsSync(destNodeModules) && existsSync(srcNodeModules)) {
    await cp(srcNodeModules, destNodeModules, { recursive: true });
    const rel = relative(process.cwd(), destNodeModules);
    // eslint-disable-next-line no-console -- electron-builder build log
    console.log(
      `[electron-builder] restored bundled Node node_modules: ${rel}`,
    );
  }

  // Mirror the check scripts/download-node.mjs runs on the source tree, but
  // against the packed output — the last point where a broken npm is still a
  // build failure instead of a broken install.
  const npmCli = isWin
    ? join(nodeDir, "node_modules", "npm", "bin", "npm-cli.js")
    : join(nodeDir, "lib", "node_modules", "npm", "bin", "npm-cli.js");
  if (!existsSync(npmCli)) {
    throw new Error(
      `[electron-builder] packaged Node is missing npm-cli.js at ${npmCli} — ` +
        "npm/npx would fail with MODULE_NOT_FOUND in the installed app. " +
        "Run `npm run download-node` and rebuild.",
    );
  }
}

function getDirSizeBytes(dir) {
  // Synchronous walk so we can run it before the rm without async juggling
  // in the hook. The directory we're sizing is always small enough (<1 GB)
  // that this is negligible compared to the rm itself.
  let total = 0;
  const stack = [dir];
  while (stack.length) {
    const next = stack.pop();
    let entries;
    try {
      entries = readdirSync(next, { withFileTypes: true });
    } catch {
      // Best-effort: skip unreadable dirs (symlink races, permission
      // errors on platform-specific node_modules subtrees, etc.). The
      // size number is only used in a build-log line, so under-counting
      // is preferable to aborting the strip.
      continue;
    }
    for (const entry of entries) {
      const p = join(next, entry.name);
      if (entry.isDirectory()) {
        stack.push(p);
      } else {
        try {
          total += statSync(p).size;
        } catch {}
      }
    }
  }
  return total;
}

/** @type {import('electron-builder').Configuration} */
const config = {
  appId: "dev.openhands.agent-canvas",
  productName: "OpenHands Agent Canvas",
  copyright: "Copyright © 2025 OpenHands contributors",

  // Stamp the packaged app with the released version (see rootPackageJson
  // note above).
  extraMetadata: { version: rootPackageJson.version },

  // Treat electron/ as the app root. electron/package.json provides the
  // Electron entry point without touching the npm-published root package.json.
  // `buildResources` points at electron/build-resources so electron-builder
  // can auto-discover the committed icon.icns / icon.ico (generated from the
  // 1024×1024 icon.png master via `npm run generate-icons`) and, for Linux,
  // icon.png itself.
  directories: {
    app: "electron",
    output: "dist-electron",
    buildResources: "electron/build-resources",
  },

  // Do not pack into asar — scripts are spawned as child processes by
  // dev-with-automation.mjs and must exist as real files on disk.
  asar: false,

  // Skip native-module rebuild — the app has no native deps.
  npmRebuild: false,

  // Strip auto-bundled node_modules (see NODE_MODULES NOTE at top of file),
  // then restore the bundled Node distribution's own npm (see
  // restoreBundledNodeNpm).
  afterPack,

  // Files included in the packaged app.
  // Paths with `from` are relative to directories.app (electron/).
  // Bare globs are also relative to directories.app.
  files: [
    // electron/ base files (main.mjs, loading.html, package.json)
    "**/*",
    // Bundle the raw 1024×1024 PNG into Resources/app/build-resources/ so
    // main.mjs can set it as the BrowserWindow icon at runtime (used for the
    // Linux taskbar; macOS reads from the .icns inside the .app bundle).
    "build-resources/icon.png",
    // Windows runtime BrowserWindow icon (main.mjs picks .ico on win32).
    "build-resources/icon.ico",
    // Scripts from project root. Mostly Node built-ins; the two spawned
    // servers additionally need RUNTIME_PACKAGES, restored into
    // Resources/app/node_modules by the afterPack hook.
    { from: "../scripts", to: "scripts", filter: ["**/*.mjs", "**/*.cjs"] },
    // Centralised version / port / path config
    { from: "../config", to: "config" },
    // Pre-built static frontend (npm run build:app output)
    { from: "../build", to: "build" },
    // Custom Python tools (canvas_ui_tool.py). dev-safe.mjs sets
    // OH_EXTRA_PYTHON_PATH to this directory so the agent-server can import
    // canvas_ui_tool at runtime. The path is computed as ../tools relative to
    // scripts/dev-safe.mjs, which resolves correctly in both dev and packaged mode.
    { from: "../tools", to: "tools" },
  ],

  // Bundled prerequisites — placed in <Resources>/ so Electron can put
  // them on PATH before starting the backend stack.
  //   bin/   — uv + uvx (downloaded by `npm run download-uv`)
  //   node/  — official Node.js distribution; provides `node` plus the
  //            bundled `npm` / `npx` that stdio MCP servers (Slack, GitHub,
  //            Figma, etc.) spawn via `npx -y <package>` (downloaded by
  //            `npm run download-node`)
  // `from` is relative to the project root (not directories.app).
  // build:desktop calls both download scripts before invoking electron-builder.
  extraResources: [
    { from: "resources/bin/", to: "bin/", filter: ["**/*"] },
    { from: "resources/node/", to: "node/", filter: ["**/*"] },
  ],

  // ── macOS ──────────────────────────────────────────────────────────────────
  //
  // Default to the native CPU arch so day-to-day `npm run build:desktop`
  // is fast (one Electron binary, one packaging pass).
  //
  // For a distributable universal build set ELECTRON_ARCH=universal:
  //   ELECTRON_ARCH=universal npm run build:desktop
  //
  // Or use the dedicated script:
  //   npm run build:desktop:universal
  //
  // CAUTION: the bundled uv/node extraResources are downloaded for the
  // BUILD HOST's architecture only (scripts/download-uv.mjs and
  // download-node.mjs have no arch override), so a "universal" build still
  // ships single-arch runtimes and breaks on the other architecture. Don't
  // distribute universal DMGs until the download scripts support multi-arch.
  //
  mac: {
    category: "public.app-category.developer-tools",
    target: [
      {
        target: "dmg",
        arch: [
          process.env.ELECTRON_ARCH ??
            (process.arch === "arm64" ? "arm64" : "x64"),
        ],
      },
    ],
    // Icon auto-discovered from directories.buildResources/icon.icns
    // (committed; regenerate with `npm run generate-icons`).
  },

  dmg: {
    title: "OpenHands Agent Canvas",
    contents: [
      { x: 130, y: 220 },
      { x: 410, y: 220, type: "link", path: "/Applications" },
    ],
    window: { width: 540, height: 380 },
    // Default is "OpenHands Agent Canvas-<version>-<arch>.dmg"; GitHub release
    // assets mangle spaces, so keep the asset name literal (matches the nsis
    // convention). ${version}/${arch}/${ext} are electron-builder macros.
    artifactName: "OpenHands-Agent-Canvas-${version}-${arch}.${ext}",
  },

  // ── Windows ────────────────────────────────────────────────────────────────
  win: {
    target: [{ target: "nsis", arch: ["x64"] }],
    // Icon auto-discovered from directories.buildResources/icon.ico
    // (committed; regenerate with `npm run generate-icons`). Also used for
    // the NSIS installer/uninstaller and the rcedit exe icon resource.
  },

  nsis: {
    oneClick: false,
    perMachine: false,
    allowToChangeInstallationDirectory: true,
    createDesktopShortcut: true,
    createStartMenuShortcut: true,
    // The default artifact name is "OpenHands Agent Canvas Setup <version>.exe";
    // GitHub release assets mangle spaces, so ship a space-free name.
    // ${version}/${ext} are electron-builder macros, not JS interpolation.
    artifactName: "OpenHands-Agent-Canvas-Setup-${version}.${ext}",
  },

  // ── Linux ──────────────────────────────────────────────────────────────────
  linux: {
    target: [
      { target: "AppImage", arch: ["x64"] },
      { target: "deb", arch: ["x64"] },
    ],
    category: "Development",
    // Icon auto-discovered from directories.buildResources/icon.png.
    // fpm-backed targets (deb) require a maintainer with an email address;
    // electron/package.json carries no author, so set it here. Without this
    // the deb step fails with "Please specify author 'email'".
    maintainer: "OpenHands <contact@all-hands.dev>",
  },
};

export default config;