diff --git a/test/test-installation-components.js b/test/test-installation-components.js
index 0a5ebed5b..db715eadc 100644
--- a/test/test-installation-components.js
+++ b/test/test-installation-components.js
@@ -18,6 +18,7 @@ const { Installer } = require('../tools/installer/core/installer');
 const { ManifestGenerator } = require('../tools/installer/core/manifest-generator');
 const { OfficialModules } = require('../tools/installer/modules/official-modules');
 const { IdeManager } = require('../tools/installer/ide/manager');
+const { ExternalModuleManager } = require('../tools/installer/modules/external-manager');
 const { clearCache, loadPlatformCodes } = require('../tools/installer/ide/platform-codes');
 
 // ANSI colors
@@ -85,6 +86,28 @@ async function createTestBmadFixture() {
   return fixtureDir;
 }
 
+async function createAutomatorSourceRootFixture() {
+  const repoRoot = await fs.mkdtemp(path.join(os.tmpdir(), 'bmad-automator-source-'));
+  const sourceRoot = path.join(repoRoot, 'skills');
+
+  for (const skillName of ['bmad-story-automator', 'bmad-story-automator-review']) {
+    const skillDir = path.join(sourceRoot, skillName);
+    await fs.ensureDir(skillDir);
+    await fs.writeFile(
+      path.join(skillDir, 'SKILL.md'),
+      ['---', `name: ${skillName}`, 'description: Automator skill', '---', '', 'Automator body.'].join('\n'),
+    );
+  }
+
+  const storySkillDir = path.join(sourceRoot, 'bmad-story-automator');
+  await fs.ensureDir(path.join(storySkillDir, 'scripts'));
+  await fs.writeFile(path.join(storySkillDir, 'scripts', 'story-automator'), '#!/usr/bin/env bash\n');
+  await fs.ensureDir(path.join(storySkillDir, 'src', 'story_automator'));
+  await fs.writeFile(path.join(storySkillDir, 'src', 'story_automator', 'cli.py'), 'def main():\n    return 0\n');
+
+  return { repoRoot, sourceRoot };
+}
+
 async function createSkillCollisionFixture() {
   const fixtureRoot = await fs.mkdtemp(path.join(os.tmpdir(), 'bmad-skill-collision-'));
   const fixtureDir = path.join(fixtureRoot, '_bmad');
@@ -3520,6 +3543,73 @@ async function runTests() {
 
   console.log('');
 
+  // ============================================================
+  // Test Suite 45: Automator External Skill-Only Module
+  // ============================================================
+  console.log(`${colors.yellow}Test Suite 45: Automator External Skill-Only Module${colors.reset}\n`);
+
+  let automatorSourceFixture42;
+  let runtimeTargetRoot42;
+  try {
+    const yaml42 = require('yaml');
+    const fallbackConfig42 = yaml42.parse(
+      await fs.readFile(path.join(__dirname, '..', 'tools', 'installer', 'modules', 'registry-fallback.yaml'), 'utf8'),
+    );
+    const automatorEntry42 = fallbackConfig42.modules['bmad-automator'];
+    assert(automatorEntry42?.code === 'baut', 'BMad Automator fallback registry code is baut');
+    assert(automatorEntry42?.['source-root'] === 'skills', 'BMad Automator fallback registry points at root skills');
+
+    const externalManager42 = new ExternalModuleManager();
+    const automatorInfo42 = externalManager42._normalizeModule(automatorEntry42);
+    assert(automatorInfo42.type === 'experimental', 'BMad Automator is marked experimental');
+    assert(automatorInfo42.sourceRoot === 'skills', 'BMad Automator uses root skills source-root for pure skill payload');
+    assert(automatorInfo42.defaultChannel === 'next', 'BMad Automator defaults to next for latest payload compatibility fixes');
+
+    automatorSourceFixture42 = await createAutomatorSourceRootFixture();
+    runtimeTargetRoot42 = await fs.mkdtemp(path.join(os.tmpdir(), 'bmad-automator-runtime-target-'));
+    const runtimeBmadDir42 = path.join(runtimeTargetRoot42, '_bmad');
+    const officialModules42 = new OfficialModules();
+    officialModules42.findModuleSource = async () => automatorSourceFixture42.sourceRoot;
+    await officialModules42.install('baut', runtimeBmadDir42, null, { skipModuleInstaller: true, silent: true });
+    assert(
+      await fs.pathExists(path.join(runtimeBmadDir42, 'baut', 'bmad-story-automator', 'scripts', 'story-automator')),
+      'BMad Automator self-contained skill install includes runtime helper',
+    );
+    assert(
+      await fs.pathExists(path.join(runtimeBmadDir42, 'baut', 'bmad-story-automator', 'src', 'story_automator', 'cli.py')),
+      'BMad Automator self-contained skill install includes Python runtime source',
+    );
+    await fs.remove(runtimeTargetRoot42).catch(() => {});
+    runtimeTargetRoot42 = null;
+
+    const escapeRoot42 = await fs.mkdtemp(path.join(os.tmpdir(), 'bmad-source-root-'));
+    const escapeRepo42 = path.join(escapeRoot42, 'repo');
+    await fs.ensureDir(escapeRepo42);
+    const escapeManager42 = new ExternalModuleManager();
+    escapeManager42.getModuleByCode = async () => ({
+      code: 'escape',
+      builtIn: false,
+      sourceRoot: '../outside',
+    });
+    escapeManager42.cloneExternalModule = async () => escapeRepo42;
+    let rejectedEscapingSourceRoot42 = false;
+    try {
+      await escapeManager42.findExternalModuleSource('escape');
+    } catch (error) {
+      rejectedEscapingSourceRoot42 = error.message.includes('source-root escapes repository');
+    } finally {
+      await fs.remove(escapeRoot42).catch(() => {});
+    }
+    assert(rejectedEscapingSourceRoot42, 'External module source-root cannot escape cloned repository');
+  } catch (error) {
+    assert(false, `Automator external skill-only module test succeeds: ${error.message}`);
+  } finally {
+    if (automatorSourceFixture42) await fs.remove(automatorSourceFixture42.repoRoot).catch(() => {});
+    if (runtimeTargetRoot42) await fs.remove(runtimeTargetRoot42).catch(() => {});
+  }
+
+  console.log('');
+
   // ============================================================
   // Summary
   // ============================================================
diff --git a/tools/installer/modules/external-manager.js b/tools/installer/modules/external-manager.js
index 7d2add4fb..e666f8612 100644
--- a/tools/installer/modules/external-manager.js
+++ b/tools/installer/modules/external-manager.js
@@ -124,6 +124,7 @@ class ExternalModuleManager {
       key: key || mod.name,
       url: mod.repository || mod.url,
       moduleDefinition: mod.module_definition || mod['module-definition'],
+      sourceRoot: mod.source_root || mod['source-root'] || mod.sourceRoot || null,
       code: mod.code,
       name: mod.display_name || mod.name,
       description: mod.description || '',
@@ -489,6 +490,19 @@ class ExternalModuleManager {
     // Clone the external module repo
     const cloneDir = await this.cloneExternalModule(moduleCode, options);
 
+    if (moduleInfo.sourceRoot) {
+      const repoRoot = path.resolve(cloneDir);
+      const sourceRoot = path.resolve(repoRoot, moduleInfo.sourceRoot);
+      const relativeSourceRoot = path.relative(repoRoot, sourceRoot);
+      if (relativeSourceRoot === '..' || relativeSourceRoot.startsWith(`..${path.sep}`) || path.isAbsolute(relativeSourceRoot)) {
+        throw new Error(`External module '${moduleCode}' source-root escapes repository: ${moduleInfo.sourceRoot}`);
+      }
+      if (!(await fs.pathExists(sourceRoot))) {
+        throw new Error(`External module '${moduleCode}' source-root not found: ${moduleInfo.sourceRoot}`);
+      }
+      return sourceRoot;
+    }
+
     // The module-definition specifies the path to module.yaml relative to repo root
     // We need to return the directory containing module.yaml
     const moduleDefinitionPath = moduleInfo.moduleDefinition; // e.g., 'skills/module.yaml'
diff --git a/tools/installer/modules/registry-fallback.yaml b/tools/installer/modules/registry-fallback.yaml
index 52bc4b4fc..139045de0 100644
--- a/tools/installer/modules/registry-fallback.yaml
+++ b/tools/installer/modules/registry-fallback.yaml
@@ -50,3 +50,14 @@ modules:
     type: bmad-org
     npmPackage: bmad-method-test-architecture-enterprise
     default_channel: stable
+
+  bmad-automator:
+    url: https://github.com/bmad-code-org/bmad-automator
+    source-root: skills
+    code: baut
+    name: "BMad Automator (Experimental)"
+    description: "Experimental pure-skill story automation. Runs only from Claude Code; supports Claude Code and Codex worker sessions; requires tmux on macOS."
+    defaultSelected: false
+    type: experimental
+    npmPackage: bmad-story-automator
+    default_channel: next