diff --git a/eslint.config.mjs b/eslint.config.mjs
index d6c20f329..23bf73aa5 100644
--- a/eslint.config.mjs
+++ b/eslint.config.mjs
@@ -114,17 +114,6 @@ export default [
     },
   },
 
-  // Module installer scripts use CommonJS for compatibility
-  {
-    files: ['**/_module-installer/**/*.js'],
-    rules: {
-      // Allow CommonJS patterns for installer scripts
-      'unicorn/prefer-module': 'off',
-      'n/no-missing-require': 'off',
-      'n/no-unpublished-require': 'off',
-    },
-  },
-
   // ESLint config file should not be checked for publish-related Node rules
   {
     files: ['eslint.config.mjs'],
diff --git a/src/bmm/_module-installer/installer.js b/src/bmm/_module-installer/installer.js
deleted file mode 100644
index 7b844a15d..000000000
--- a/src/bmm/_module-installer/installer.js
+++ /dev/null
@@ -1,48 +0,0 @@
-const fs = require('fs-extra');
-const path = require('node:path');
-const chalk = require('chalk');
-
-// Directories to create from config
-const DIRECTORIES = ['output_folder', 'planning_artifacts', 'implementation_artifacts'];
-
-/**
- * BMM Module Installer
- * Creates output directories configured in module config
- *
- * @param {Object} options - Installation options
- * @param {string} options.projectRoot - The root directory of the target project
- * @param {Object} options.config - Module configuration from module.yaml
- * @param {Array<string>} options.installedIDEs - Array of IDE codes that were installed
- * @param {Object} options.logger - Logger instance for output
- * @returns {Promise<boolean>} - Success status
- */
-async function install(options) {
-  const { projectRoot, config, logger } = options;
-
-  try {
-    logger.log(chalk.blue('🚀 Installing BMM Module...'));
-
-    // Create configured directories
-    for (const configKey of DIRECTORIES) {
-      const configValue = config[configKey];
-      if (!configValue) continue;
-
-      const dirPath = configValue.replace('{project-root}/', '');
-      const fullPath = path.join(projectRoot, dirPath);
-
-      if (!(await fs.pathExists(fullPath))) {
-        const dirName = configKey.replace('_', ' ');
-        logger.log(chalk.yellow(`Creating ${dirName} directory: ${dirPath}`));
-        await fs.ensureDir(fullPath);
-      }
-    }
-
-    logger.log(chalk.green('✓ BMM Module installation complete'));
-    return true;
-  } catch (error) {
-    logger.error(chalk.red(`Error installing BMM module: ${error.message}`));
-    return false;
-  }
-}
-
-module.exports = { install };
diff --git a/src/bmm/module.yaml b/src/bmm/module.yaml
index a9884e586..76f6b7433 100644
--- a/src/bmm/module.yaml
+++ b/src/bmm/module.yaml
@@ -42,3 +42,9 @@ project_knowledge: # Artifacts from research, document-project output, other lon
   prompt: "Where should long-term project knowledge be stored? (docs, research, references)"
   default: "docs"
   result: "{project-root}/{value}"
+
+# Directories to create during installation (declarative, no code execution)
+directories:
+  - "{planning_artifacts}"
+  - "{implementation_artifacts}"
+  - "{project_knowledge}"
diff --git a/src/core/_module-installer/installer.js b/src/core/_module-installer/installer.js
deleted file mode 100644
index d77bc62fa..000000000
--- a/src/core/_module-installer/installer.js
+++ /dev/null
@@ -1,60 +0,0 @@
-const chalk = require('chalk');
-
-/**
- * Core Module Installer
- * Standard module installer function that executes after IDE installations
- *
- * @param {Object} options - Installation options
- * @param {string} options.projectRoot - The root directory of the target project
- * @param {Object} options.config - Module configuration from module.yaml
- * @param {Array<string>} options.installedIDEs - Array of IDE codes that were installed
- * @param {Object} options.logger - Logger instance for output
- * @returns {Promise<boolean>} - Success status
- */
-async function install(options) {
-  const { projectRoot, config, installedIDEs, logger } = options;
-
-  try {
-    logger.log(chalk.blue('🏗️  Installing Core Module...'));
-
-    // Core agent configs are created by the main installer's createAgentConfigs method
-    // No need to create them here - they'll be handled along with all other agents
-
-    // Handle IDE-specific configurations if needed
-    if (installedIDEs && installedIDEs.length > 0) {
-      logger.log(chalk.cyan(`Configuring Core for IDEs: ${installedIDEs.join(', ')}`));
-
-      // Add any IDE-specific Core configurations here
-      for (const ide of installedIDEs) {
-        await configureForIDE(ide, projectRoot, config, logger);
-      }
-    }
-
-    logger.log(chalk.green('✓ Core Module installation complete'));
-    return true;
-  } catch (error) {
-    logger.error(chalk.red(`Error installing Core module: ${error.message}`));
-    return false;
-  }
-}
-
-/**
- * Configure Core module for specific IDE
- * @private
- */
-async function configureForIDE(ide) {
-  // Add IDE-specific configurations here
-  switch (ide) {
-    case 'claude-code': {
-      // Claude Code specific Core configurations
-      break;
-    }
-    // Add more IDEs as needed
-    default: {
-      // No specific configuration needed
-      break;
-    }
-  }
-}
-
-module.exports = { install };
diff --git a/tools/cli/external-official-modules.yaml b/tools/cli/external-official-modules.yaml
index 431ded4a3..d6ae06ee6 100644
--- a/tools/cli/external-official-modules.yaml
+++ b/tools/cli/external-official-modules.yaml
@@ -42,13 +42,12 @@ modules:
     type: bmad-org
     npmPackage: bmad-method-test-architecture-enterprise
 
-# TODO: Enable once fixes applied:
-
-# whiteport-design-system:
-#   url: https://github.com/bmad-code-org/bmad-method-wds-expansion
-#   module-definition: src/module.yaml
-#   code: WDS
-#   name: "Whiteport UX Design System"
-#   description: "UX design framework with Figma integration"
-#   defaultSelected: false
-#   type: community
+  # whiteport-design-system:
+  #   url: https://github.com/bmad-code-org/bmad-method-wds-expansion
+  #   module-definition: src/module.yaml
+  #   code: wds
+  #   name: "Whiteport UX Design System"
+  #   description: "UX design framework with Figma integration"
+  #   defaultSelected: false
+  #   type: community
+  #   npmPackage: bmad-method-wds-expansion
diff --git a/tools/cli/installers/lib/core/config-collector.js b/tools/cli/installers/lib/core/config-collector.js
index 1a0f50d29..1fd410fa3 100644
--- a/tools/cli/installers/lib/core/config-collector.js
+++ b/tools/cli/installers/lib/core/config-collector.js
@@ -188,20 +188,18 @@ class ConfigCollector {
       this.allAnswers = {};
     }
 
-    // Load module's install config schema
+    // Load module's config schema from module.yaml
     // First, try the standard src/modules location
-    let installerConfigPath = path.join(getModulePath(moduleName), '_module-installer', 'module.yaml');
     let moduleConfigPath = path.join(getModulePath(moduleName), 'module.yaml');
 
     // If not found in src/modules, we need to find it by searching the project
-    if (!(await fs.pathExists(installerConfigPath)) && !(await fs.pathExists(moduleConfigPath))) {
+    if (!(await fs.pathExists(moduleConfigPath))) {
       // Use the module manager to find the module source
       const { ModuleManager } = require('../modules/manager');
       const moduleManager = new ModuleManager();
       const moduleSourcePath = await moduleManager.findModuleSource(moduleName);
 
       if (moduleSourcePath) {
-        installerConfigPath = path.join(moduleSourcePath, '_module-installer', 'module.yaml');
         moduleConfigPath = path.join(moduleSourcePath, 'module.yaml');
       }
     }
@@ -211,8 +209,6 @@ class ConfigCollector {
 
     if (await fs.pathExists(moduleConfigPath)) {
       configPath = moduleConfigPath;
-    } else if (await fs.pathExists(installerConfigPath)) {
-      configPath = installerConfigPath;
     } else {
       // Check if this is a custom module with custom.yaml
       const { ModuleManager } = require('../modules/manager');
@@ -221,9 +217,8 @@ class ConfigCollector {
 
       if (moduleSourcePath) {
         const rootCustomConfigPath = path.join(moduleSourcePath, 'custom.yaml');
-        const moduleInstallerCustomPath = path.join(moduleSourcePath, '_module-installer', 'custom.yaml');
 
-        if ((await fs.pathExists(rootCustomConfigPath)) || (await fs.pathExists(moduleInstallerCustomPath))) {
+        if (await fs.pathExists(rootCustomConfigPath)) {
           isCustomModule = true;
           // For custom modules, we don't have an install-config schema, so just use existing values
           // The custom.yaml values will be loaded and merged during installation
@@ -500,28 +495,24 @@ class ConfigCollector {
     }
     // Load module's config
     // First, check if we have a custom module path for this module
-    let installerConfigPath = null;
     let moduleConfigPath = null;
 
     if (this.customModulePaths && this.customModulePaths.has(moduleName)) {
       const customPath = this.customModulePaths.get(moduleName);
-      installerConfigPath = path.join(customPath, '_module-installer', 'module.yaml');
       moduleConfigPath = path.join(customPath, 'module.yaml');
     } else {
       // Try the standard src/modules location
-      installerConfigPath = path.join(getModulePath(moduleName), '_module-installer', 'module.yaml');
       moduleConfigPath = path.join(getModulePath(moduleName), 'module.yaml');
     }
 
     // If not found in src/modules or custom paths, search the project
-    if (!(await fs.pathExists(installerConfigPath)) && !(await fs.pathExists(moduleConfigPath))) {
+    if (!(await fs.pathExists(moduleConfigPath))) {
       // Use the module manager to find the module source
       const { ModuleManager } = require('../modules/manager');
       const moduleManager = new ModuleManager();
       const moduleSourcePath = await moduleManager.findModuleSource(moduleName);
 
       if (moduleSourcePath) {
-        installerConfigPath = path.join(moduleSourcePath, '_module-installer', 'module.yaml');
         moduleConfigPath = path.join(moduleSourcePath, 'module.yaml');
       }
     }
@@ -529,8 +520,6 @@ class ConfigCollector {
     let configPath = null;
     if (await fs.pathExists(moduleConfigPath)) {
       configPath = moduleConfigPath;
-    } else if (await fs.pathExists(installerConfigPath)) {
-      configPath = installerConfigPath;
     } else {
       // No config for this module
       return;
diff --git a/tools/cli/installers/lib/core/installer.js b/tools/cli/installers/lib/core/installer.js
index 44f31090d..c25b76748 100644
--- a/tools/cli/installers/lib/core/installer.js
+++ b/tools/cli/installers/lib/core/installer.js
@@ -1070,11 +1070,11 @@ class Installer {
         warn: (msg) => console.warn(msg), // Always show warnings
       };
 
-      // Run core module installer if core was installed
+      // Create directories for core module if core was installed
       if (config.installCore || resolution.byModule.core) {
-        spinner.message('Running core module installer...');
+        spinner.message('Creating core module directories...');
 
-        await this.moduleManager.runModuleInstaller('core', bmadDir, {
+        await this.moduleManager.createModuleDirectories('core', bmadDir, {
           installedIDEs: config.ides || [],
           moduleConfig: moduleConfigs.core || {},
           coreConfig: moduleConfigs.core || {},
@@ -1083,13 +1083,13 @@ class Installer {
         });
       }
 
-      // Run installers for user-selected modules
+      // Create directories for user-selected modules
       if (config.modules && config.modules.length > 0) {
         for (const moduleName of config.modules) {
-          spinner.message(`Running ${moduleName} module installer...`);
+          spinner.message(`Creating ${moduleName} module directories...`);
 
-          // Pass installed IDEs and module config to module installer
-          await this.moduleManager.runModuleInstaller(moduleName, bmadDir, {
+          // Pass installed IDEs and module config to directory creator
+          await this.moduleManager.createModuleDirectories(moduleName, bmadDir, {
             installedIDEs: config.ides || [],
             moduleConfig: moduleConfigs[moduleName] || {},
             coreConfig: moduleConfigs.core || {},
@@ -1904,8 +1904,8 @@ class Installer {
         continue;
       }
 
-      // Skip _module-installer directory - it's only needed at install time
-      if (file.startsWith('_module-installer/') || file === 'module.yaml') {
+      // Skip module.yaml at root - it's only needed at install time
+      if (file === 'module.yaml') {
         continue;
       }
 
@@ -1958,10 +1958,6 @@ class Installer {
       const fullPath = path.join(dir, entry.name);
 
       if (entry.isDirectory()) {
-        // Skip _module-installer directories
-        if (entry.name === '_module-installer') {
-          continue;
-        }
         const subFiles = await this.getFileList(fullPath, baseDir);
         files.push(...subFiles);
       } else {
diff --git a/tools/cli/installers/lib/custom/handler.js b/tools/cli/installers/lib/custom/handler.js
index 6256e3cd2..52595e4ff 100644
--- a/tools/cli/installers/lib/custom/handler.js
+++ b/tools/cli/installers/lib/custom/handler.js
@@ -55,7 +55,7 @@ class CustomHandler {
             // Found a custom.yaml file
             customPaths.push(fullPath);
           } else if (
-            entry.name === 'module.yaml' && // Check if this is a custom module (either in _module-installer or in root directory)
+            entry.name === 'module.yaml' && // Check if this is a custom module (in root directory)
             // Skip if it's in src/modules (those are standard modules)
             !fullPath.includes(path.join('src', 'modules'))
           ) {
diff --git a/tools/cli/installers/lib/modules/manager.js b/tools/cli/installers/lib/modules/manager.js
index a0b50048c..bc199a53d 100644
--- a/tools/cli/installers/lib/modules/manager.js
+++ b/tools/cli/installers/lib/modules/manager.js
@@ -236,17 +236,11 @@ class ModuleManager {
   async getModuleInfo(modulePath, defaultName, sourceDescription) {
     // Check for module structure (module.yaml OR custom.yaml)
     const moduleConfigPath = path.join(modulePath, 'module.yaml');
-    const installerConfigPath = path.join(modulePath, '_module-installer', 'module.yaml');
-    const customConfigPath = path.join(modulePath, '_module-installer', 'custom.yaml');
     const rootCustomConfigPath = path.join(modulePath, 'custom.yaml');
     let configPath = null;
 
     if (await fs.pathExists(moduleConfigPath)) {
       configPath = moduleConfigPath;
-    } else if (await fs.pathExists(installerConfigPath)) {
-      configPath = installerConfigPath;
-    } else if (await fs.pathExists(customConfigPath)) {
-      configPath = customConfigPath;
     } else if (await fs.pathExists(rootCustomConfigPath)) {
       configPath = rootCustomConfigPath;
     }
@@ -268,7 +262,7 @@ class ModuleManager {
       description: 'BMAD Module',
       version: '5.0.0',
       source: sourceDescription,
-      isCustom: configPath === customConfigPath || configPath === rootCustomConfigPath || isCustomSource,
+      isCustom: configPath === rootCustomConfigPath || isCustomSource,
     };
 
     // Read module config for metadata
@@ -541,7 +535,6 @@ class ModuleManager {
     // Check if this is a custom module and read its custom.yaml values
     let customConfig = null;
     const rootCustomConfigPath = path.join(sourcePath, 'custom.yaml');
-    const moduleInstallerCustomPath = path.join(sourcePath, '_module-installer', 'custom.yaml');
 
     if (await fs.pathExists(rootCustomConfigPath)) {
       try {
@@ -550,13 +543,6 @@ class ModuleManager {
       } catch (error) {
         await prompts.log.warn(`Warning: Failed to read custom.yaml for ${moduleName}: ${error.message}`);
       }
-    } else if (await fs.pathExists(moduleInstallerCustomPath)) {
-      try {
-        const customContent = await fs.readFile(moduleInstallerCustomPath, 'utf8');
-        customConfig = yaml.parse(customContent);
-      } catch (error) {
-        await prompts.log.warn(`Warning: Failed to read custom.yaml for ${moduleName}: ${error.message}`);
-      }
     }
 
     // If this is a custom module, merge its values into the module config
@@ -585,9 +571,9 @@ class ModuleManager {
     // Process agent files to inject activation block
     await this.processAgentFiles(targetPath, moduleName);
 
-    // Call module-specific installer if it exists (unless explicitly skipped)
+    // Create directories declared in module.yaml (unless explicitly skipped)
     if (!options.skipModuleInstaller) {
-      await this.runModuleInstaller(moduleName, bmadDir, options);
+      await this.createModuleDirectories(moduleName, bmadDir, options);
     }
 
     // Capture version info for manifest
@@ -743,8 +729,8 @@ class ModuleManager {
         continue;
       }
 
-      // Skip _module-installer directory - it's only needed at install time
-      if (file.startsWith('_module-installer/') || file === 'module.yaml') {
+      // Skip module.yaml at root - it's only needed at install time
+      if (file === 'module.yaml') {
         continue;
       }
 
@@ -1259,80 +1245,101 @@ class ModuleManager {
   }
 
   /**
-   * Run module-specific installer if it exists
+   * Create directories declared in module.yaml's `directories` key
+   * This replaces the security-risky module installer pattern with declarative config
    * @param {string} moduleName - Name of the module
    * @param {string} bmadDir - Target bmad directory
    * @param {Object} options - Installation options
+   * @param {Object} options.moduleConfig - Module configuration from config collector
+   * @param {Object} options.coreConfig - Core configuration
    */
-  async runModuleInstaller(moduleName, bmadDir, options = {}) {
+  async createModuleDirectories(moduleName, bmadDir, options = {}) {
+    const moduleConfig = options.moduleConfig || {};
+    const projectRoot = path.dirname(bmadDir);
+
     // Special handling for core module - it's in src/core not src/modules
     let sourcePath;
     if (moduleName === 'core') {
       sourcePath = getSourcePath('core');
     } else {
-      sourcePath = await this.findModuleSource(moduleName, { silent: options.silent });
+      sourcePath = await this.findModuleSource(moduleName, { silent: true });
       if (!sourcePath) {
-        // No source found, skip module installer
-        return;
+        return; // No source found, skip
       }
     }
 
-    const installerDir = path.join(sourcePath, '_module-installer');
-    // Prefer .cjs (always CommonJS) then fall back to .js
-    const cjsPath = path.join(installerDir, 'installer.cjs');
-    const jsPath = path.join(installerDir, 'installer.js');
-    const hasCjs = await fs.pathExists(cjsPath);
-    const installerPath = hasCjs ? cjsPath : jsPath;
-
-    // Check if module has a custom installer
-    if (!hasCjs && !(await fs.pathExists(jsPath))) {
-      return; // No custom installer
+    // Read module.yaml to find the `directories` key
+    const moduleYamlPath = path.join(sourcePath, 'module.yaml');
+    if (!(await fs.pathExists(moduleYamlPath))) {
+      return; // No module.yaml, skip
     }
 
+    let moduleYaml;
     try {
-      // .cjs files are always CommonJS and safe to require().
-      // .js files may be ESM (when the package sets "type":"module"),
-      // so use dynamic import() which handles both CJS and ESM.
-      let moduleInstaller;
-      if (hasCjs) {
-        moduleInstaller = require(installerPath);
-      } else {
-        const { pathToFileURL } = require('node:url');
-        const imported = await import(pathToFileURL(installerPath).href);
-        // CJS module.exports lands on .default; ESM default can be object, function, or class
-        moduleInstaller = imported.default == null ? imported : imported.default;
+      const yamlContent = await fs.readFile(moduleYamlPath, 'utf8');
+      moduleYaml = yaml.parse(yamlContent);
+    } catch {
+      return; // Invalid YAML, skip
+    }
+
+    if (!moduleYaml || !moduleYaml.directories) {
+      return; // No directories declared, skip
+    }
+
+    // Get color utility for styled output
+    const color = await prompts.getColor();
+    const directories = moduleYaml.directories;
+    const wdsFolders = moduleYaml.wds_folders || [];
+
+    for (const dirRef of directories) {
+      // Parse variable reference like "{design_artifacts}"
+      const varMatch = dirRef.match(/^\{([^}]+)\}$/);
+      if (!varMatch) {
+        // Not a variable reference, skip
+        continue;
       }
 
-      if (typeof moduleInstaller.install === 'function') {
-        // Get project root (parent of bmad directory)
-        const projectRoot = path.dirname(bmadDir);
+      const configKey = varMatch[1];
+      const dirValue = moduleConfig[configKey];
+      if (!dirValue || typeof dirValue !== 'string') {
+        continue; // No value or not a string, skip
+      }
 
-        // Prepare logger (use console if not provided)
-        const logger = options.logger || {
-          log: console.log,
-          error: console.error,
-          warn: console.warn,
-        };
+      // Strip {project-root}/ prefix if present
+      let dirPath = dirValue.replace(/^\{project-root\}\/?/, '');
 
-        // Call the module installer
-        const result = await moduleInstaller.install({
-          projectRoot,
-          config: options.moduleConfig || {},
-          coreConfig: options.coreConfig || {},
-          installedIDEs: options.installedIDEs || [],
-          logger,
-        });
+      // Handle remaining {project-root} anywhere in the path
+      dirPath = dirPath.replaceAll('{project-root}', '');
 
-        if (!result) {
-          await prompts.log.warn(`Module installer for ${moduleName} returned false`);
+      // Resolve to absolute path
+      const fullPath = path.join(projectRoot, dirPath);
+
+      // Validate path is within project root (prevent directory traversal)
+      const normalizedPath = path.normalize(fullPath);
+      const normalizedRoot = path.normalize(projectRoot);
+      if (!normalizedPath.startsWith(normalizedRoot + path.sep) && normalizedPath !== normalizedRoot) {
+        await prompts.log.warn(color.yellow(`Warning: ${configKey} path escapes project root, skipping: ${dirPath}`));
+        continue;
+      }
+
+      // Create directory if it doesn't exist
+      if (!(await fs.pathExists(fullPath))) {
+        const dirName = configKey.replaceAll('_', ' ');
+        await prompts.log.message(color.yellow(`Creating ${dirName} directory: ${dirPath}`));
+        await fs.ensureDir(fullPath);
+      }
+
+      // Create WDS subfolders if this is the design_artifacts directory
+      if (configKey === 'design_artifacts' && wdsFolders.length > 0) {
+        await prompts.log.message(color.cyan('Creating WDS folder structure...'));
+        for (const subfolder of wdsFolders) {
+          const subPath = path.join(fullPath, subfolder);
+          if (!(await fs.pathExists(subPath))) {
+            await fs.ensureDir(subPath);
+            await prompts.log.message(color.dim(`  ✓ ${subfolder}/`));
+          }
         }
       }
-    } catch {
-      // Post-install scripts are optional; module files are already installed.
-      // TODO: Eliminate post-install scripts entirely by adding a `directories` key
-      // to module.yaml that declares which config keys are paths to auto-create.
-      // The main installer can then handle directory creation centrally, removing
-      // the need for per-module installer.js scripts and their CJS/ESM issues.
     }
   }
 
@@ -1402,10 +1409,6 @@ class ModuleManager {
       const fullPath = path.join(dir, entry.name);
 
       if (entry.isDirectory()) {
-        // Skip _module-installer directories
-        if (entry.name === '_module-installer') {
-          continue;
-        }
         const subFiles = await this.getFileList(fullPath, baseDir);
         files.push(...subFiles);
       } else {
diff --git a/tools/validate-file-refs.js b/tools/validate-file-refs.js
index 22b02da7f..bf92f31f8 100644
--- a/tools/validate-file-refs.js
+++ b/tools/validate-file-refs.js
@@ -42,7 +42,7 @@ const STRICT = process.argv.includes('--strict');
 const SCAN_EXTENSIONS = new Set(['.yaml', '.yml', '.md', '.xml', '.csv']);
 
 // Skip directories
-const SKIP_DIRS = new Set(['node_modules', '_module-installer', '.git']);
+const SKIP_DIRS = new Set(['node_modules', '.git']);
 
 // Pattern: {project-root}/_bmad/ references
 const PROJECT_ROOT_REF = /\{project-root\}\/_bmad\/([^\s'"<>})\]`]+)/g;