diff --git a/packages/rules/__tests__/init/detect-stack.test.js b/packages/rules/__tests__/init/detect-stack.test.js
new file mode 100644
index 00000000..20f4154c
--- /dev/null
+++ b/packages/rules/__tests__/init/detect-stack.test.js
@@ -0,0 +1,120 @@
+const { describe, it, beforeEach, afterEach } = require('node:test');
+const assert = require('node:assert/strict');
+const fs = require('node:fs');
+const path = require('node:path');
+const os = require('node:os');
+
+const { detectStack } = require('../../lib/init/detect-stack');
+
+describe('detectStack', () => {
+  let tmpDir;
+
+  beforeEach(() => {
+    tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'cb-test-'));
+  });
+
+  afterEach(() => {
+    fs.rmSync(tmpDir, { recursive: true, force: true });
+  });
+
+  it('detects Node.js project from package.json', () => {
+    fs.writeFileSync(
+      path.join(tmpDir, 'package.json'),
+      JSON.stringify({ name: 'my-app', dependencies: { express: '^4.0.0' } })
+    );
+    const result = detectStack(tmpDir);
+    assert.equal(result.runtime, 'node');
+    assert.ok(result.frameworks.includes('express'));
+  });
+
+  it('detects React project', () => {
+    fs.writeFileSync(
+      path.join(tmpDir, 'package.json'),
+      JSON.stringify({ dependencies: { react: '^18.0.0', 'react-dom': '^18.0.0' } })
+    );
+    const result = detectStack(tmpDir);
+    assert.equal(result.runtime, 'node');
+    assert.ok(result.frameworks.includes('react'));
+    assert.equal(result.category, 'frontend');
+  });
+
+  it('detects Next.js project', () => {
+    fs.writeFileSync(
+      path.join(tmpDir, 'package.json'),
+      JSON.stringify({ dependencies: { next: '^14.0.0', react: '^18.0.0' } })
+    );
+    const result = detectStack(tmpDir);
+    assert.ok(result.frameworks.includes('next'));
+    assert.equal(result.category, 'fullstack');
+  });
+
+  it('detects NestJS backend project', () => {
+    fs.writeFileSync(
+      path.join(tmpDir, 'package.json'),
+      JSON.stringify({ dependencies: { '@nestjs/core': '^10.0.0' } })
+    );
+    const result = detectStack(tmpDir);
+    assert.ok(result.frameworks.includes('nestjs'));
+    assert.equal(result.category, 'backend');
+  });
+
+  it('detects Python project from pyproject.toml', () => {
+    fs.writeFileSync(path.join(tmpDir, 'pyproject.toml'), '[project]\nname = "myapp"\n');
+    const result = detectStack(tmpDir);
+    assert.equal(result.runtime, 'python');
+    assert.equal(result.category, 'backend');
+  });
+
+  it('detects Django in pyproject.toml', () => {
+    fs.writeFileSync(
+      path.join(tmpDir, 'pyproject.toml'),
+      '[project]\ndependencies = ["django>=4.0"]\n'
+    );
+    const result = detectStack(tmpDir);
+    assert.equal(result.runtime, 'python');
+    assert.ok(result.frameworks.includes('django'));
+  });
+
+  it('detects Go project from go.mod', () => {
+    fs.writeFileSync(path.join(tmpDir, 'go.mod'), 'module example.com/myapp\n\ngo 1.21\n');
+    const result = detectStack(tmpDir);
+    assert.equal(result.runtime, 'go');
+    assert.equal(result.category, 'backend');
+  });
+
+  it('detects Rust project from Cargo.toml', () => {
+    fs.writeFileSync(
+      path.join(tmpDir, 'Cargo.toml'),
+      '[package]\nname = "myapp"\nversion = "0.1.0"\n'
+    );
+    const result = detectStack(tmpDir);
+    assert.equal(result.runtime, 'rust');
+    assert.equal(result.category, 'backend');
+  });
+
+  it('returns unknown for empty directory', () => {
+    const result = detectStack(tmpDir);
+    assert.equal(result.runtime, 'unknown');
+    assert.deepEqual(result.frameworks, []);
+    assert.equal(result.category, 'unknown');
+  });
+
+  it('detects TypeScript usage', () => {
+    fs.writeFileSync(
+      path.join(tmpDir, 'package.json'),
+      JSON.stringify({ devDependencies: { typescript: '^5.0.0' } })
+    );
+    const result = detectStack(tmpDir);
+    assert.equal(result.language, 'typescript');
+  });
+
+  it('detects Vue.js frontend project', () => {
+    fs.writeFileSync(
+      path.join(tmpDir, 'package.json'),
+      JSON.stringify({ dependencies: { vue: '^3.0.0' } })
+    );
+    const result = detectStack(tmpDir);
+    assert.ok(result.frameworks.includes('vue'));
+    assert.equal(result.category, 'frontend');
+  });
+});
diff --git a/packages/rules/__tests__/init/generate-config.test.js b/packages/rules/__tests__/init/generate-config.test.js
new file mode 100644
index 00000000..e9627527
--- /dev/null
+++ b/packages/rules/__tests__/init/generate-config.test.js
@@ -0,0 +1,77 @@
+const { describe, it, beforeEach, afterEach } = require('node:test');
+const assert = require('node:assert/strict');
+const fs = require('node:fs');
+const path = require('node:path');
+const os = require('node:os');
+
+const { generateConfig } = require('../../lib/init/generate-config');
+
+describe('generateConfig', () => {
+  let tmpDir;
+
+  beforeEach(() => {
+    tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'cb-cfg-'));
+  });
+
+  afterEach(() => {
+    fs.rmSync(tmpDir, { recursive: true, force: true });
+  });
+
+  it('creates codingbuddy.config.json with defaults', () => {
+    const options = {
+      language: 'en',
+      primaryAgent: 'software-engineer',
+      techStack: { runtime: 'node', language: 'typescript', frameworks: ['next'], category: 'fullstack' },
+    };
+    generateConfig(tmpDir, options);
+
+    const configPath = path.join(tmpDir, 'codingbuddy.config.json');
+    assert.ok(fs.existsSync(configPath));
+
+    const config = JSON.parse(fs.readFileSync(configPath, 'utf-8'));
+    assert.equal(config.language, 'en');
+    assert.equal(config.primaryAgent, 'software-engineer');
+    assert.equal(config.techStack.runtime, 'node');
+  });
+
+  it('includes all required fields', () => {
+    generateConfig(tmpDir, {
+      language: 'ko',
+      primaryAgent: 'backend-developer',
+      techStack: { runtime: 'python', language: 'python', frameworks: ['django'], category: 'backend' },
+    });
+
+    const config = JSON.parse(fs.readFileSync(path.join(tmpDir, 'codingbuddy.config.json'), 'utf-8'));
+    assert.ok('language' in config);
+    assert.ok('primaryAgent' in config);
+    assert.ok('techStack' in config);
+    assert.ok('version' in config);
+  });
+
+  it('does not overwrite existing config', () => {
+    const configPath = path.join(tmpDir, 'codingbuddy.config.json');
+    fs.writeFileSync(configPath, JSON.stringify({ language: 'ja', custom: true }));
+
+    const result = generateConfig(tmpDir, {
+      language: 'en',
+      primaryAgent: 'software-engineer',
+      techStack: { runtime: 'node', language: 'javascript', frameworks: [], category: 'backend' },
+    });
+
+    assert.equal(result.skipped, true);
+    const config = JSON.parse(fs.readFileSync(configPath, 'utf-8'));
+    assert.equal(config.language, 'ja');
+    assert.equal(config.custom, true);
+  });
+
+  it('writes formatted JSON', () => {
+    generateConfig(tmpDir, {
+      language: 'en',
+      primaryAgent: 'frontend-developer',
+      techStack: { runtime: 'node', language: 'typescript', frameworks: ['react'], category: 'frontend' },
+    });
+
+    const raw = fs.readFileSync(path.join(tmpDir, 'codingbuddy.config.json'), 'utf-8');
+    assert.ok(raw.includes('\n'), 'should be formatted with newlines');
+  });
+});
diff --git a/packages/rules/__tests__/init/scaffold.test.js b/packages/rules/__tests__/init/scaffold.test.js
new file mode 100644
index 00000000..9de6007d
--- /dev/null
+++ b/packages/rules/__tests__/init/scaffold.test.js
@@ -0,0 +1,59 @@
+const { describe, it, beforeEach, afterEach } = require('node:test');
+const assert = require('node:assert/strict');
+const fs = require('node:fs');
+const path = require('node:path');
+const os = require('node:os');
+
+const { scaffold } = require('../../lib/init/scaffold');
+
+describe('scaffold', () => {
+  let tmpDir;
+  const rulesSource = path.resolve(__dirname, '../../.ai-rules');
+
+  beforeEach(() => {
+    tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'cb-scaffold-'));
+  });
+
+  afterEach(() => {
+    fs.rmSync(tmpDir, { recursive: true, force: true });
+  });
+
+  it('creates .ai-rules directory in target', () => {
+    scaffold(tmpDir, { source: rulesSource });
+    assert.ok(fs.existsSync(path.join(tmpDir, '.ai-rules')));
+  });
+
+  it('copies rules/ directory', () => {
+    scaffold(tmpDir, { source: rulesSource });
+    assert.ok(fs.existsSync(path.join(tmpDir, '.ai-rules', 'rules')));
+    assert.ok(fs.existsSync(path.join(tmpDir, '.ai-rules', 'rules', 'core.md')));
+  });
+
+  it('copies agents/ directory', () => {
+    scaffold(tmpDir, { source: rulesSource });
+    assert.ok(fs.existsSync(path.join(tmpDir, '.ai-rules', 'agents')));
+  });
+
+  it('copies README.md', () => {
+    scaffold(tmpDir, { source: rulesSource });
+    assert.ok(fs.existsSync(path.join(tmpDir, '.ai-rules', 'README.md')));
+  });
+
+  it('does not overwrite existing .ai-rules', () => {
+    const existingDir = path.join(tmpDir, '.ai-rules');
+    fs.mkdirSync(existingDir);
+    fs.writeFileSync(path.join(existingDir, 'custom.md'), 'my rules');
+
+    const result = scaffold(tmpDir, { source: rulesSource });
+    assert.equal(result.skipped, true);
+    assert.ok(fs.existsSync(path.join(existingDir, 'custom.md')));
+  });
+
+  it('returns list of copied directories', () => {
+    const result = scaffold(tmpDir, { source: rulesSource });
+    assert.equal(result.skipped, false);
+    assert.ok(result.dirs.length > 0);
+    assert.ok(result.dirs.includes('rules'));
+    assert.ok(result.dirs.includes('agents'));
+  });
+});
diff --git a/packages/rules/__tests__/init/suggest-agent.test.js b/packages/rules/__tests__/init/suggest-agent.test.js
new file mode 100644
index 00000000..7cc8dd38
--- /dev/null
+++ b/packages/rules/__tests__/init/suggest-agent.test.js
@@ -0,0 +1,56 @@
+const { describe, it } = require('node:test');
+const assert = require('node:assert/strict');
+
+const { suggestAgent } = require('../../lib/init/suggest-agent');
+
+describe('suggestAgent', () => {
+  it('suggests frontend-developer for React projects', () => {
+    const result = suggestAgent({ runtime: 'node', category: 'frontend', frameworks: ['react'] });
+    assert.equal(result, 'frontend-developer');
+  });
+
+  it('suggests frontend-developer for Vue projects', () => {
+    const result = suggestAgent({ runtime: 'node', category: 'frontend', frameworks: ['vue'] });
+    assert.equal(result, 'frontend-developer');
+  });
+
+  it('suggests software-engineer for Next.js fullstack', () => {
+    const result = suggestAgent({ runtime: 'node', category: 'fullstack', frameworks: ['next', 'react'] });
+    assert.equal(result, 'software-engineer');
+  });
+
+  it('suggests backend-developer for NestJS', () => {
+    const result = suggestAgent({ runtime: 'node', category: 'backend', frameworks: ['nestjs'] });
+    assert.equal(result, 'backend-developer');
+  });
+
+  it('suggests backend-developer for Python', () => {
+    const result = suggestAgent({ runtime: 'python', category: 'backend', frameworks: ['django'] });
+    assert.equal(result, 'backend-developer');
+  });
+
+  it('suggests backend-developer for Go', () => {
+    const result = suggestAgent({ runtime: 'go', category: 'backend', frameworks: [] });
+    assert.equal(result, 'backend-developer');
+  });
+
+  it('suggests systems-developer for Rust', () => {
+    const result = suggestAgent({ runtime: 'rust', category: 'backend', frameworks: [] });
+    assert.equal(result, 'systems-developer');
+  });
+
+  it('suggests mobile-developer for React Native', () => {
+    const result = suggestAgent({ runtime: 'node', category: 'mobile', frameworks: ['react-native'] });
+    assert.equal(result, 'mobile-developer');
+  });
+
+  it('suggests software-engineer for unknown stack', () => {
+    const result = suggestAgent({ runtime: 'unknown', category: 'unknown', frameworks: [] });
+    assert.equal(result, 'software-engineer');
+  });
+
+  it('suggests data-scientist for Python with jupyter/pandas', () => {
+    const result = suggestAgent({ runtime: 'python', category: 'backend', frameworks: ['pandas'] });
+    assert.equal(result, 'data-scientist');
+  });
+});
diff --git a/packages/rules/bin/cli.js b/packages/rules/bin/cli.js
index 69ff29fc..06f5e201 100755
--- a/packages/rules/bin/cli.js
+++ b/packages/rules/bin/cli.js
@@ -139,11 +139,11 @@ function validate() {
 }
 
 function init() {
-  console.log(
-    'codingbuddy init is not yet implemented.\n' +
-      'See https://github.com/JeremyDev87/codingbuddy/issues/813 for progress.',
-  );
-  process.exit(0);
+  const { run } = require('../lib/init');
+  run().catch((err) => {
+    console.error('Error:', err.message);
+    process.exit(1);
+  });
 }
 
 // --- Main ---
diff --git a/packages/rules/lib/init/detect-stack.js b/packages/rules/lib/init/detect-stack.js
new file mode 100644
index 00000000..f6c3f2fa
--- /dev/null
+++ b/packages/rules/lib/init/detect-stack.js
@@ -0,0 +1,148 @@
+'use strict';
+
+const fs = require('node:fs');
+const path = require('node:path');
+
+const FRONTEND_FRAMEWORKS = ['react', 'vue', 'angular', 'svelte', 'solid-js'];
+const FULLSTACK_FRAMEWORKS = ['next', 'nuxt', 'remix', 'sveltekit', 'astro'];
+const BACKEND_FRAMEWORKS = [
+  '@nestjs/core', 'express', 'fastify', 'koa', 'hapi',
+  '@hono/node-server', 'hono',
+];
+const MOBILE_FRAMEWORKS = ['react-native', 'expo', '@capacitor/core', 'ionic'];
+
+/**
+ * Detect tech stack from project files in the given directory.
+ * @param {string} cwd - Directory to scan
+ * @returns {{ runtime: string, language: string, frameworks: string[], category: string }}
+ */
+function detectStack(cwd) {
+  const result = { runtime: 'unknown', language: 'javascript', frameworks: [], category: 'unknown' };
+
+  if (tryDetectNode(cwd, result)) return result;
+  if (tryDetectPython(cwd, result)) return result;
+  if (tryDetectGo(cwd, result)) return result;
+  if (tryDetectRust(cwd, result)) return result;
+
+  result.language = 'unknown';
+  return result;
+}
+
+function tryDetectNode(cwd, result) {
+  const pkgPath = path.join(cwd, 'package.json');
+  if (!fs.existsSync(pkgPath)) return false;
+
+  let pkg;
+  try {
+    pkg = JSON.parse(fs.readFileSync(pkgPath, 'utf-8'));
+  } catch {
+    return false;
+  }
+
+  result.runtime = 'node';
+
+  const allDeps = {
+    ...pkg.dependencies,
+    ...pkg.devDependencies,
+  };
+
+  // Detect language
+  if (allDeps.typescript) {
+    result.language = 'typescript';
+  }
+
+  // Detect frameworks
+  const detected = [];
+
+  for (const fw of FULLSTACK_FRAMEWORKS) {
+    if (allDeps[fw]) detected.push(fw);
+  }
+  for (const fw of FRONTEND_FRAMEWORKS) {
+    if (allDeps[fw]) detected.push(fw);
+  }
+  for (const fw of BACKEND_FRAMEWORKS) {
+    if (allDeps[fw]) {
+      const name = fw.startsWith('@nestjs') ? 'nestjs' : fw;
+      detected.push(name);
+    }
+  }
+  for (const fw of MOBILE_FRAMEWORKS) {
+    if (allDeps[fw]) detected.push(fw);
+  }
+
+  result.frameworks = detected;
+
+  // Determine category
+  if (detected.some(f => MOBILE_FRAMEWORKS.includes(f) || f === 'react-native' || f === 'expo')) {
+    result.category = 'mobile';
+  } else if (detected.some(f => FULLSTACK_FRAMEWORKS.includes(f))) {
+    result.category = 'fullstack';
+  } else if (detected.some(f => FRONTEND_FRAMEWORKS.includes(f))) {
+    result.category = 'frontend';
+  } else if (detected.some(f => ['nestjs', ...BACKEND_FRAMEWORKS.map(b => b.startsWith('@') ? 'nestjs' : b)].includes(f))) {
+    result.category = 'backend';
+  } else {
+    result.category = 'backend'; // default for Node without frameworks
+  }
+
+  return true;
+}
+
+function tryDetectPython(cwd, result) {
+  const pyprojectPath = path.join(cwd, 'pyproject.toml');
+  if (!fs.existsSync(pyprojectPath)) return false;
+
+  result.runtime = 'python';
+  result.language = 'python';
+  result.category = 'backend';
+
+  const content = fs.readFileSync(pyprojectPath, 'utf-8');
+  const pyFrameworks = {
+    django: 'django',
+    flask: 'flask',
+    fastapi: 'fastapi',
+    starlette: 'starlette',
+  };
+
+  for (const [key, name] of Object.entries(pyFrameworks)) {
+    if (content.toLowerCase().includes(key)) {
+      result.frameworks.push(name);
+    }
+  }
+
+  return true;
+}
+
+function tryDetectGo(cwd, result) {
+  const goModPath = path.join(cwd, 'go.mod');
+  if (!fs.existsSync(goModPath)) return false;
+
+  result.runtime = 'go';
+  result.language = 'go';
+  result.category = 'backend';
+
+  const content = fs.readFileSync(goModPath, 'utf-8');
+  if (content.includes('github.com/gin-gonic/gin')) result.frameworks.push('gin');
+  if (content.includes('github.com/gofiber/fiber')) result.frameworks.push('fiber');
+  if (content.includes('github.com/labstack/echo')) result.frameworks.push('echo');
+
+  return true;
+}
+
+function tryDetectRust(cwd, result) {
+  const cargoPath = path.join(cwd, 'Cargo.toml');
+  if (!fs.existsSync(cargoPath)) return false;
+
+  result.runtime = 'rust';
+  result.language = 'rust';
+  result.category = 'backend';
+
+  const content = fs.readFileSync(cargoPath, 'utf-8');
+  if (content.includes('actix-web')) result.frameworks.push('actix-web');
+  if (content.includes('axum')) result.frameworks.push('axum');
+  if (content.includes('rocket')) result.frameworks.push('rocket');
+
+  return true;
+}
+
+module.exports = { detectStack };
diff --git a/packages/rules/lib/init/generate-config.js b/packages/rules/lib/init/generate-config.js
new file mode 100644
index 00000000..5aecdb50
--- /dev/null
+++ b/packages/rules/lib/init/generate-config.js
@@ -0,0 +1,31 @@
+'use strict';
+
+const fs = require('node:fs');
+const path = require('node:path');
+
+/**
+ * Generate codingbuddy.config.json in the target directory.
+ * @param {string} cwd - Target directory
+ * @param {{ language: string, primaryAgent: string, techStack: object }} options
+ * @returns {{ created: boolean, skipped: boolean, path: string }}
+ */
+function generateConfig(cwd, options) {
+  const configPath = path.join(cwd, 'codingbuddy.config.json');
+
+  if (fs.existsSync(configPath)) {
+    return { created: false, skipped: true, path: configPath };
+  }
+
+  const config = {
+    version: '1.0.0',
+    language: options.language || 'en',
+    primaryAgent: options.primaryAgent || 'software-engineer',
+    techStack: options.techStack || {},
+  };
+
+  fs.writeFileSync(configPath, JSON.stringify(config, null, 2) + '\n', 'utf-8');
+
+  return { created: true, skipped: false, path: configPath };
+}
+
+module.exports = { generateConfig };
diff --git a/packages/rules/lib/init/index.js b/packages/rules/lib/init/index.js
new file mode 100644
index 00000000..cdd07d0d
--- /dev/null
+++ b/packages/rules/lib/init/index.js
@@ -0,0 +1,86 @@
+'use strict';
+
+const path = require('node:path');
+const { detectStack } = require('./detect-stack');
+const { suggestAgent } = require('./suggest-agent');
+const { generateConfig } = require('./generate-config');
+const { scaffold } = require('./scaffold');
+const { ask, select, confirm } = require('./prompt');
+
+const LANGUAGES = ['en', 'ko', 'ja', 'zh', 'es'];
+
+/**
+ * Run the codingbuddy init wizard.
+ * @param {string} [cwd=process.cwd()]
+ */
+async function run(cwd) {
+  const targetDir = cwd || process.cwd();
+
+  console.log('\n  codingbuddy init\n');
+  console.log('  Initializing codingbuddy for your project...\n');
+
+  // Step 1: Detect tech stack
+  console.log('  Detecting tech stack...');
+  const stack = detectStack(targetDir);
+
+  if (stack.runtime !== 'unknown') {
+    console.log(`  Detected: ${stack.runtime} (${stack.language})`);
+    if (stack.frameworks.length > 0) {
+      console.log(`  Frameworks: ${stack.frameworks.join(', ')}`);
+    }
+    console.log(`  Category: ${stack.category}`);
+  } else {
+    console.log('  No recognized project files found.');
+  }
+
+  // Step 2: Language selection
+  const language = await select('Select communication language:', LANGUAGES, 0);
+  console.log(`  Language: ${language}`);
+
+  // Step 3: Agent suggestion
+  const suggested = suggestAgent(stack);
+  console.log(`\n  Recommended primary agent: ${suggested}`);
+  const useAgent = await confirm(`  Use ${suggested} as primary agent?`, true);
+
+  let primaryAgent = suggested;
+  if (!useAgent) {
+    primaryAgent = await ask('  Enter agent name', 'software-engineer');
+  }
+
+  // Step 4: Generate config
+  console.log('\n  Creating codingbuddy.config.json...');
+  const configResult = generateConfig(targetDir, {
+    language,
+    primaryAgent,
+    techStack: stack,
+  });
+
+  if (configResult.skipped) {
+    console.log('  codingbuddy.config.json already exists, skipped.');
+  } else {
+    console.log('  Created codingbuddy.config.json');
+  }
+
+  // Step 5: Scaffold .ai-rules
+  const doScaffold = await confirm('  Scaffold .ai-rules/ directory with default rules?', true);
+
+  if (doScaffold) {
+    console.log('  Scaffolding .ai-rules/...');
+    const scaffoldResult = scaffold(targetDir);
+
+    if (scaffoldResult.skipped) {
+      console.log('  .ai-rules/ already exists, skipped.');
+    } else {
+      console.log(`  Created .ai-rules/ with: ${scaffoldResult.dirs.join(', ')}`);
+    }
+  }
+
+  // Done
+  console.log('\n  Done! codingbuddy is ready.\n');
+  console.log('  Next steps:');
+  console.log('    1. Review codingbuddy.config.json');
+  console.log('    2. Customize .ai-rules/ for your project');
+  console.log('    3. Start coding with your AI assistant\n');
+}
+
+module.exports = { run };
diff --git a/packages/rules/lib/init/prompt.js b/packages/rules/lib/init/prompt.js
new file mode 100644
index 00000000..08bd5578
--- /dev/null
+++ b/packages/rules/lib/init/prompt.js
@@ -0,0 +1,60 @@
+'use strict';
+
+const readline = require('node:readline');
+
+/**
+ * Ask a question via stdin and return the answer.
+ * @param {string} question
+ * @param {string} [defaultValue]
+ * @returns {Promise<string>}
+ */
+function ask(question, defaultValue) {
+  const rl = readline.createInterface({ input: process.stdin, output: process.stdout });
+  const suffix = defaultValue ? ` (${defaultValue})` : '';
+
+  return new Promise((resolve) => {
+    rl.question(`${question}${suffix}: `, (answer) => {
+      rl.close();
+      resolve(answer.trim() || defaultValue || '');
+    });
+  });
+}
+
+/**
+ * Ask user to select from a list of options.
+ * @param {string} question
+ * @param {string[]} options
+ * @param {number} [defaultIndex=0]
+ * @returns {Promise<string>}
+ */
+async function select(question, options, defaultIndex = 0) {
+  console.log(`\n${question}`);
+  options.forEach((opt, i) => {
+    const marker = i === defaultIndex ? '>' : ' ';
+    console.log(`  ${marker} ${i + 1}. ${opt}`);
+  });
+
+  const answer = await ask('Select', String(defaultIndex + 1));
+  const index = parseInt(answer, 10) - 1;
+
+  if (index >= 0 && index < options.length) {
+    return options[index];
+  }
+  return options[defaultIndex];
+}
+
+/**
+ * Ask yes/no question.
+ * @param {string} question
+ * @param {boolean} [defaultValue=true]
+ * @returns {Promise<boolean>}
+ */
+async function confirm(question, defaultValue = true) {
+  const hint = defaultValue ? 'Y/n' : 'y/N';
+  const answer = await ask(`${question} (${hint})`, '');
+
+  if (!answer) return defaultValue;
+  return answer.toLowerCase().startsWith('y');
+}
+
+module.exports = { ask, select, confirm };
diff --git a/packages/rules/lib/init/scaffold.js b/packages/rules/lib/init/scaffold.js
new file mode 100644
index 00000000..1b939449
--- /dev/null
+++ b/packages/rules/lib/init/scaffold.js
@@ -0,0 +1,67 @@
+'use strict';
+
+const fs = require('node:fs');
+const path = require('node:path');
+
+const DEFAULT_SOURCE = path.resolve(__dirname, '../../.ai-rules');
+
+// Directories to always scaffold
+const SCAFFOLD_DIRS = ['rules', 'agents'];
+// Top-level files to always copy
+const SCAFFOLD_FILES = ['README.md'];
+
+/**
+ * Scaffold .ai-rules/ structure in the target directory.
+ * @param {string} cwd - Target directory
+ * @param {{ source?: string }} options
+ * @returns {{ skipped: boolean, dirs: string[], targetPath: string }}
+ */
+function scaffold(cwd, options = {}) {
+  const source = options.source || DEFAULT_SOURCE;
+  const targetDir = path.join(cwd, '.ai-rules');
+
+  if (fs.existsSync(targetDir)) {
+    return { skipped: true, dirs: [], targetPath: targetDir };
+  }
+
+  fs.mkdirSync(targetDir, { recursive: true });
+
+  const copiedDirs = [];
+
+  // Copy directories
+  for (const dir of SCAFFOLD_DIRS) {
+    const srcDir = path.join(source, dir);
+    if (fs.existsSync(srcDir)) {
+      copyDirRecursive(srcDir, path.join(targetDir, dir));
+      copiedDirs.push(dir);
+    }
+  }
+
+  // Copy top-level files
+  for (const file of SCAFFOLD_FILES) {
+    const srcFile = path.join(source, file);
+    if (fs.existsSync(srcFile)) {
+      fs.copyFileSync(srcFile, path.join(targetDir, file));
+    }
+  }
+
+  return { skipped: false, dirs: copiedDirs, targetPath: targetDir };
+}
+
+function copyDirRecursive(src, dest) {
+  fs.mkdirSync(dest, { recursive: true });
+  const entries = fs.readdirSync(src, { withFileTypes: true });
+
+  for (const entry of entries) {
+    const srcPath = path.join(src, entry.name);
+    const destPath = path.join(dest, entry.name);
+
+    if (entry.isDirectory()) {
+      copyDirRecursive(srcPath, destPath);
+    } else {
+      fs.copyFileSync(srcPath, destPath);
+    }
+  }
+}
+
+module.exports = { scaffold };
diff --git a/packages/rules/lib/init/suggest-agent.js b/packages/rules/lib/init/suggest-agent.js
new file mode 100644
index 00000000..9716457e
--- /dev/null
+++ b/packages/rules/lib/init/suggest-agent.js
@@ -0,0 +1,46 @@
+'use strict';
+
+const AGENT_MAP = {
+  mobile: 'mobile-developer',
+  frontend: 'frontend-developer',
+  fullstack: 'software-engineer',
+};
+
+const RUNTIME_AGENTS = {
+  rust: 'systems-developer',
+  go: 'backend-developer',
+  python: 'backend-developer',
+};
+
+const DATA_SCIENCE_FRAMEWORKS = ['pandas', 'numpy', 'scipy', 'jupyter', 'tensorflow', 'pytorch', 'scikit-learn'];
+
+/**
+ * Suggest the best primary agent based on detected tech stack.
+ * @param {{ runtime: string, category: string, frameworks: string[] }} stack
+ * @returns {string} Agent name (e.g. 'frontend-developer')
+ */
+function suggestAgent(stack) {
+  // Data science detection for Python
+  if (stack.runtime === 'python' && stack.frameworks.some(f => DATA_SCIENCE_FRAMEWORKS.includes(f))) {
+    return 'data-scientist';
+  }
+
+  // Category-based mapping
+  if (AGENT_MAP[stack.category]) {
+    return AGENT_MAP[stack.category];
+  }
+
+  // Runtime-based mapping
+  if (RUNTIME_AGENTS[stack.runtime]) {
+    return RUNTIME_AGENTS[stack.runtime];
+  }
+
+  // Backend Node.js
+  if (stack.runtime === 'node' && stack.category === 'backend') {
+    return 'backend-developer';
+  }
+
+  return 'software-engineer';
+}
+
+module.exports = { suggestAgent };
diff --git a/packages/rules/package.json b/packages/rules/package.json
index c55c03db..947233a9 100644
--- a/packages/rules/package.json
+++ b/packages/rules/package.json
@@ -7,11 +7,15 @@
   "bin": {
     "codingbuddy": "./bin/cli.js"
   },
+  "scripts": {
+    "test": "node --test __tests__/**/*.test.js"
+  },
   "files": [
     "index.js",
     "index.d.ts",
     ".ai-rules",
-    "bin"
+    "bin",
+    "lib"
   ],
   "keywords": [
     "ai",