diff --git a/package.json b/package.json
index 875d788f5..a26398fdf 100644
--- a/package.json
+++ b/package.json
@@ -70,7 +70,6 @@
     "chalk": "^4.1.2",
     "commander": "^14.0.0",
     "csv-parse": "^6.1.0",
-    "fs-extra": "^11.3.0",
     "glob": "^11.0.3",
     "ignore": "^7.0.5",
     "js-yaml": "^4.1.0",
diff --git a/test/test-installation-components.js b/test/test-installation-components.js
index 10639bab8..f1c1be486 100644
--- a/test/test-installation-components.js
+++ b/test/test-installation-components.js
@@ -13,7 +13,7 @@
 
 const path = require('node:path');
 const os = require('node:os');
-const fs = require('fs-extra');
+const fs = require('../tools/installer/fs-native');
 const { Installer } = require('../tools/installer/core/installer');
 const { ManifestGenerator } = require('../tools/installer/core/manifest-generator');
 const { OfficialModules } = require('../tools/installer/modules/official-modules');
diff --git a/tools/installer/commands/status.js b/tools/installer/commands/status.js
index 49c0afd73..c7f4a816c 100644
--- a/tools/installer/commands/status.js
+++ b/tools/installer/commands/status.js
@@ -19,7 +19,7 @@ module.exports = {
       const { bmadDir } = await installer.findBmadDir(projectDir);
 
       // Check if bmad directory exists
-      const fs = require('fs-extra');
+      const fs = require('../fs-native');
       if (!(await fs.pathExists(bmadDir))) {
         await prompts.log.warn('No BMAD installation found in the current directory.');
         await prompts.log.message(`Expected location: ${bmadDir}`);
diff --git a/tools/installer/commands/uninstall.js b/tools/installer/commands/uninstall.js
index d0e168a15..727b7b0ef 100644
--- a/tools/installer/commands/uninstall.js
+++ b/tools/installer/commands/uninstall.js
@@ -1,5 +1,5 @@
 const path = require('node:path');
-const fs = require('fs-extra');
+const fs = require('../fs-native');
 const prompts = require('../prompts');
 const { Installer } = require('../core/installer');
 
diff --git a/tools/installer/core/existing-install.js b/tools/installer/core/existing-install.js
index 643f1d946..6bbf191d1 100644
--- a/tools/installer/core/existing-install.js
+++ b/tools/installer/core/existing-install.js
@@ -1,5 +1,5 @@
 const path = require('node:path');
-const fs = require('fs-extra');
+const fs = require('../fs-native');
 const yaml = require('yaml');
 const { Manifest } = require('./manifest');
 
diff --git a/tools/installer/core/install-paths.js b/tools/installer/core/install-paths.js
index f1c50ee43..e7fb98b6d 100644
--- a/tools/installer/core/install-paths.js
+++ b/tools/installer/core/install-paths.js
@@ -1,5 +1,5 @@
 const path = require('node:path');
-const fs = require('fs-extra');
+const fs = require('../fs-native');
 const { getProjectRoot } = require('../project-root');
 const { BMAD_FOLDER_NAME } = require('../ide/shared/path-utils');
 
diff --git a/tools/installer/core/installer.js b/tools/installer/core/installer.js
index 95e16adfe..2a9ff3272 100644
--- a/tools/installer/core/installer.js
+++ b/tools/installer/core/installer.js
@@ -1,5 +1,5 @@
 const path = require('node:path');
-const fs = require('fs-extra');
+const fs = require('../fs-native');
 const { Manifest } = require('./manifest');
 const { OfficialModules } = require('../modules/official-modules');
 const { IdeManager } = require('../ide/manager');
diff --git a/tools/installer/core/manifest-generator.js b/tools/installer/core/manifest-generator.js
index 13e33af56..477142888 100644
--- a/tools/installer/core/manifest-generator.js
+++ b/tools/installer/core/manifest-generator.js
@@ -1,5 +1,5 @@
 const path = require('node:path');
-const fs = require('fs-extra');
+const fs = require('../fs-native');
 const yaml = require('yaml');
 const crypto = require('node:crypto');
 const csv = require('csv-parse/sync');
diff --git a/tools/installer/core/manifest.js b/tools/installer/core/manifest.js
index aaa86649a..2dc94ae9f 100644
--- a/tools/installer/core/manifest.js
+++ b/tools/installer/core/manifest.js
@@ -1,5 +1,5 @@
 const path = require('node:path');
-const fs = require('fs-extra');
+const fs = require('../fs-native');
 const crypto = require('node:crypto');
 const { getProjectRoot } = require('../project-root');
 const prompts = require('../prompts');
diff --git a/tools/installer/file-ops.js b/tools/installer/file-ops.js
index 5cd7970d8..2a2869930 100644
--- a/tools/installer/file-ops.js
+++ b/tools/installer/file-ops.js
@@ -1,4 +1,4 @@
-const fs = require('fs-extra');
+const fs = require('./fs-native');
 const path = require('node:path');
 const crypto = require('node:crypto');
 
diff --git a/tools/installer/fs-native.js b/tools/installer/fs-native.js
new file mode 100644
index 000000000..b6a4abfa5
--- /dev/null
+++ b/tools/installer/fs-native.js
@@ -0,0 +1,111 @@
+// Drop-in replacement for fs-extra using native node:fs APIs.
+// Eliminates graceful-fs monkey-patching that causes non-deterministic
+// file loss during multi-module installs on macOS (issue #1779).
+const fsp = require('node:fs/promises');
+const fs = require('node:fs');
+const path = require('node:path');
+
+async function pathExists(p) {
+  try {
+    await fsp.access(p);
+    return true;
+  } catch {
+    return false;
+  }
+}
+
+async function ensureDir(dir) {
+  await fsp.mkdir(dir, { recursive: true });
+}
+
+async function remove(p) {
+  await fsp.rm(p, { recursive: true, force: true });
+}
+
+async function copy(src, dest, options = {}) {
+  const filterFn = options.filter;
+  const overwrite = options.overwrite !== false;
+  const srcStat = await fsp.stat(src);
+
+  if (srcStat.isFile()) {
+    if (filterFn && !(await filterFn(src, dest))) return;
+    await fsp.mkdir(path.dirname(dest), { recursive: true });
+    if (!overwrite) {
+      try {
+        await fsp.access(dest);
+        if (options.errorOnExist) throw new Error(`${dest} already exists`);
+        return;
+      } catch (error) {
+        if (error.message.includes('already exists')) throw error;
+      }
+    }
+    await fsp.copyFile(src, dest);
+    return;
+  }
+
+  if (srcStat.isDirectory()) {
+    if (filterFn && !(await filterFn(src, dest))) return;
+    await fsp.mkdir(dest, { recursive: true });
+    const entries = await fsp.readdir(src, { withFileTypes: true });
+    for (const entry of entries) {
+      await copy(path.join(src, entry.name), path.join(dest, entry.name), options);
+    }
+  }
+}
+
+async function move(src, dest) {
+  try {
+    await fsp.rename(src, dest);
+  } catch (error) {
+    if (error.code === 'EXDEV') {
+      await copy(src, dest);
+      await fsp.rm(src, { recursive: true, force: true });
+    } else {
+      throw error;
+    }
+  }
+}
+
+function readJsonSync(p) {
+  return JSON.parse(fs.readFileSync(p, 'utf8'));
+}
+
+async function writeJson(p, data, options = {}) {
+  const spaces = options.spaces ?? 2;
+  await fsp.writeFile(p, JSON.stringify(data, null, spaces) + '\n', 'utf8');
+}
+
+module.exports = {
+  // Native async (node:fs/promises)
+  readFile: fsp.readFile,
+  writeFile: fsp.writeFile,
+  stat: fsp.stat,
+  readdir: fsp.readdir,
+  access: fsp.access,
+  rename: fsp.rename,
+  unlink: fsp.unlink,
+  chmod: fsp.chmod,
+  mkdir: fsp.mkdir,
+  mkdtemp: fsp.mkdtemp,
+  copyFile: fsp.copyFile,
+  rm: fsp.rm,
+
+  // fs-extra compatible helpers (native implementations)
+  pathExists,
+  ensureDir,
+  remove,
+  copy,
+  move,
+  readJsonSync,
+  writeJson,
+
+  // Sync methods from core node:fs
+  existsSync: fs.existsSync.bind(fs),
+  readFileSync: fs.readFileSync.bind(fs),
+  writeFileSync: fs.writeFileSync.bind(fs),
+  createReadStream: fs.createReadStream.bind(fs),
+  pathExistsSync: fs.existsSync.bind(fs),
+
+  // Constants
+  constants: fs.constants,
+};
diff --git a/tools/installer/ide/_config-driven.js b/tools/installer/ide/_config-driven.js
index 9c7df4bc5..563818f67 100644
--- a/tools/installer/ide/_config-driven.js
+++ b/tools/installer/ide/_config-driven.js
@@ -1,6 +1,6 @@
 const os = require('node:os');
 const path = require('node:path');
-const fs = require('fs-extra');
+const fs = require('../fs-native');
 const yaml = require('yaml');
 const prompts = require('../prompts');
 const csv = require('csv-parse/sync');
diff --git a/tools/installer/ide/platform-codes.js b/tools/installer/ide/platform-codes.js
index 32d82e9cc..f29be8fcb 100644
--- a/tools/installer/ide/platform-codes.js
+++ b/tools/installer/ide/platform-codes.js
@@ -1,4 +1,4 @@
-const fs = require('fs-extra');
+const fs = require('../fs-native');
 const path = require('node:path');
 const yaml = require('yaml');
 
diff --git a/tools/installer/ide/shared/skill-manifest.js b/tools/installer/ide/shared/skill-manifest.js
index 746d5d16f..1dfc7eb35 100644
--- a/tools/installer/ide/shared/skill-manifest.js
+++ b/tools/installer/ide/shared/skill-manifest.js
@@ -1,5 +1,5 @@
 const path = require('node:path');
-const fs = require('fs-extra');
+const fs = require('../../fs-native');
 const yaml = require('yaml');
 
 /**
diff --git a/tools/installer/message-loader.js b/tools/installer/message-loader.js
index 03ba7eca1..97f02d6e4 100644
--- a/tools/installer/message-loader.js
+++ b/tools/installer/message-loader.js
@@ -1,4 +1,4 @@
-const fs = require('fs-extra');
+const fs = require('./fs-native');
 const path = require('node:path');
 const yaml = require('yaml');
 const prompts = require('./prompts');
diff --git a/tools/installer/modules/community-manager.js b/tools/installer/modules/community-manager.js
index 0f88cffff..3e0217688 100644
--- a/tools/installer/modules/community-manager.js
+++ b/tools/installer/modules/community-manager.js
@@ -1,4 +1,4 @@
-const fs = require('fs-extra');
+const fs = require('../fs-native');
 const os = require('node:os');
 const path = require('node:path');
 const { execSync } = require('node:child_process');
diff --git a/tools/installer/modules/custom-module-manager.js b/tools/installer/modules/custom-module-manager.js
index e0f8b7085..482c4dc43 100644
--- a/tools/installer/modules/custom-module-manager.js
+++ b/tools/installer/modules/custom-module-manager.js
@@ -1,4 +1,4 @@
-const fs = require('fs-extra');
+const fs = require('../fs-native');
 const os = require('node:os');
 const path = require('node:path');
 const { execSync } = require('node:child_process');
diff --git a/tools/installer/modules/external-manager.js b/tools/installer/modules/external-manager.js
index 0b8f5074c..5169ffb50 100644
--- a/tools/installer/modules/external-manager.js
+++ b/tools/installer/modules/external-manager.js
@@ -1,4 +1,4 @@
-const fs = require('fs-extra');
+const fs = require('../fs-native');
 const os = require('node:os');
 const path = require('node:path');
 const { execSync } = require('node:child_process');
diff --git a/tools/installer/modules/official-modules.js b/tools/installer/modules/official-modules.js
index 6158a7863..19dc0f4dc 100644
--- a/tools/installer/modules/official-modules.js
+++ b/tools/installer/modules/official-modules.js
@@ -1,5 +1,5 @@
 const path = require('node:path');
-const fs = require('fs-extra');
+const fs = require('../fs-native');
 const yaml = require('yaml');
 const prompts = require('../prompts');
 const { getProjectRoot, getSourcePath, getModulePath } = require('../project-root');
diff --git a/tools/installer/modules/plugin-resolver.js b/tools/installer/modules/plugin-resolver.js
index 9fbf325a2..58e20ab88 100644
--- a/tools/installer/modules/plugin-resolver.js
+++ b/tools/installer/modules/plugin-resolver.js
@@ -1,4 +1,4 @@
-const fs = require('fs-extra');
+const fs = require('../fs-native');
 const path = require('node:path');
 const yaml = require('yaml');
 
diff --git a/tools/installer/project-root.js b/tools/installer/project-root.js
index 26063f81f..037f1a430 100644
--- a/tools/installer/project-root.js
+++ b/tools/installer/project-root.js
@@ -1,5 +1,5 @@
 const path = require('node:path');
-const fs = require('fs-extra');
+const fs = require('./fs-native');
 
 /**
  * Find the BMAD project root directory by looking for package.json
diff --git a/tools/installer/ui.js b/tools/installer/ui.js
index 9e48c647a..d1c5189e9 100644
--- a/tools/installer/ui.js
+++ b/tools/installer/ui.js
@@ -1,6 +1,6 @@
 const path = require('node:path');
 const os = require('node:os');
-const fs = require('fs-extra');
+const fs = require('./fs-native');
 const { CLIUtils } = require('./cli-utils');
 const { ExternalModuleManager } = require('./modules/external-manager');
 const { getProjectRoot } = require('./project-root');
diff --git a/tools/migrate-custom-module-paths.js b/tools/migrate-custom-module-paths.js
index 13aa3e710..b199e8bfe 100755
--- a/tools/migrate-custom-module-paths.js
+++ b/tools/migrate-custom-module-paths.js
@@ -3,7 +3,7 @@
  * This should be run once to update existing installations
  */
 
-const fs = require('fs-extra');
+const fs = require('./installer/fs-native');
 const path = require('node:path');
 const yaml = require('yaml');
 const chalk = require('chalk');