diff --git a/src/cli/commands/index-cmd.ts b/src/cli/commands/index-cmd.ts
new file mode 100644
index 0000000..84a6fed
--- /dev/null
+++ b/src/cli/commands/index-cmd.ts
@@ -0,0 +1,61 @@
+import { Command } from 'commander';
+import chalk from 'chalk';
+import { indexProject } from '../../core/indexer';
+
+export const indexCommand = new Command('index')
+  .description('Index a codebase to create component nodes')
+  .argument('[path]', 'Path to index', '.')
+  .option('--update', 'Only update changed files (incremental)')
+  .option('--dry-run', 'Preview what would be indexed without making changes')
+  .option('--depth <n>', 'Maximum directory depth', '10')
+  .option('--lang <language>', 'Only index specific language (ts, js, py)')
+  .option('--ignore <patterns>', 'Additional ignore patterns (comma-separated)')
+  .action(async (inputPath: string, opts) => {
+    const startTime = Date.now();
+
+    if (opts.dryRun) {
+      console.log(chalk.yellow('Dry run mode - no changes will be made\n'));
+    }
+
+    console.log(chalk.cyan(`Indexing ${inputPath}...`));
+
+    try {
+      const result = await indexProject(inputPath, {
+        update: opts.update,
+        dryRun: opts.dryRun,
+        maxDepth: parseInt(opts.depth),
+        language: opts.lang,
+        ignore: opts.ignore?.split(',').map((s: string) => s.trim()),
+      });
+
+      const elapsed = ((Date.now() - startTime) / 1000).toFixed(2);
+
+      console.log();
+      console.log(chalk.green(`✓ Indexed ${result.projectName} (${result.projectType})`));
+      console.log();
+      console.log(`  Files scanned:        ${result.files.length}`);
+      console.log(`  Components created:   ${result.componentsCreated}`);
+      console.log(`  Components updated:   ${result.componentsUpdated}`);
+      console.log(`  Components removed:   ${result.componentsRemoved}`);
+      console.log(`  Relationships:        ${result.relationshipsCreated}`);
+      if (result.architectureNodeId) {
+        console.log(`  Architecture node:    ${result.architectureNodeId.slice(0, 8)}`);
+      }
+      console.log();
+      console.log(chalk.dim(`Completed in ${elapsed}s`));
+
+      if (opts.dryRun && result.files.length > 0) {
+        console.log();
+        console.log(chalk.yellow('Files that would be indexed:'));
+        for (const file of result.files.slice(0, 20)) {
+          console.log(`  ${file}`);
+        }
+        if (result.files.length > 20) {
+          console.log(chalk.dim(`  ... and ${result.files.length - 20} more`));
+        }
+      }
+    } catch (err: any) {
+      console.error(chalk.red(`Error: ${err.message}`));
+      process.exit(1);
+    }
+  });
diff --git a/src/cli/index.ts b/src/cli/index.ts
index 8bc0b6c..27602a8 100644
--- a/src/cli/index.ts
+++ b/src/cli/index.ts
@@ -16,6 +16,7 @@ import { diffCommand } from './commands/diff';
 import { restoreCommand } from './commands/restore';
 import { captureCommand, captureHookCommand, configCommand } from './commands/capture';
 import { contextCommand, contextHookCommand } from './commands/context';
+import { indexCommand } from './commands/index-cmd';
 import { closeDb } from '../core/db';
 
 const program = new Command();
@@ -44,6 +45,7 @@ program.addCommand(captureHookCommand);
 program.addCommand(contextCommand);
 program.addCommand(contextHookCommand);
 program.addCommand(configCommand);
+program.addCommand(indexCommand);
 
 program.hook('postAction', () => {
   closeDb();
diff --git a/src/core/indexer/architecture.ts b/src/core/indexer/architecture.ts
new file mode 100644
index 0000000..e79c00a
--- /dev/null
+++ b/src/core/indexer/architecture.ts
@@ -0,0 +1,79 @@
+import * as path from 'path';
+import { Node } from '../../types';
+import { ProjectInfo } from './detector';
+import { getDirectoryTree } from './scanner';
+
+export interface ArchitectureSummary {
+  projectName: string;
+  projectType: string;
+  description: string;
+  techStack: string[];
+  keyComponents: { name: string; path: string; exports: number }[];
+  directoryStructure: string;
+}
+
+export function generateArchitectureSummary(
+  projectRoot: string,
+  projectInfo: ProjectInfo,
+  components: Node[]
+): ArchitectureSummary {
+  // Determine tech stack from dependencies
+  const techStack: string[] = [projectInfo.type];
+  const deps = [...projectInfo.dependencies, ...(projectInfo.devDependencies || [])];
+
+  // Detect frameworks/libraries
+  if (deps.includes('react') || deps.includes('react-dom')) techStack.push('React');
+  if (deps.includes('vue')) techStack.push('Vue');
+  if (deps.includes('express')) techStack.push('Express');
+  if (deps.includes('fastify')) techStack.push('Fastify');
+  if (deps.includes('next')) techStack.push('Next.js');
+  if (deps.includes('typescript')) techStack.push('TypeScript');
+  if (deps.includes('prisma')) techStack.push('Prisma');
+  if (deps.includes('sequelize')) techStack.push('Sequelize');
+  if (deps.includes('mongoose')) techStack.push('MongoDB');
+  if (deps.includes('better-sqlite3') || deps.includes('sqlite3')) techStack.push('SQLite');
+
+  // Get key components (most exports or largest)
+  const keyComponents = components
+    .map(n => ({
+      name: n.title,
+      path: n.metadata?.filePath as string || '',
+      exports: (n.metadata?.exports as string[])?.length || 0,
+    }))
+    .sort((a, b) => b.exports - a.exports)
+    .slice(0, 10);
+
+  return {
+    projectName: projectInfo.name,
+    projectType: projectInfo.type,
+    description: projectInfo.description || `A ${projectInfo.type} project`,
+    techStack,
+    keyComponents,
+    directoryStructure: getDirectoryTree(projectRoot, 3),
+  };
+}
+
+export function formatArchitectureAsMarkdown(summary: ArchitectureSummary): string {
+  const sections: string[] = [];
+
+  sections.push(`# ${summary.projectName} Architecture\n`);
+  sections.push(`${summary.description}\n`);
+
+  sections.push(`## Tech Stack\n`);
+  sections.push(summary.techStack.map(t => `- ${t}`).join('\n') + '\n');
+
+  if (summary.keyComponents.length > 0) {
+    sections.push(`## Key Components\n`);
+    for (const comp of summary.keyComponents) {
+      sections.push(`- **${comp.name}** (${comp.path}) - ${comp.exports} exports`);
+    }
+    sections.push('');
+  }
+
+  sections.push(`## Directory Structure\n`);
+  sections.push('```');
+  sections.push(summary.directoryStructure);
+  sections.push('```');
+
+  return sections.join('\n');
+}
diff --git a/src/core/indexer/detector.ts b/src/core/indexer/detector.ts
new file mode 100644
index 0000000..a2f710e
--- /dev/null
+++ b/src/core/indexer/detector.ts
@@ -0,0 +1,145 @@
+import * as fs from 'fs';
+import * as path from 'path';
+
+export type ProjectType = 'nodejs' | 'python' | 'rust' | 'go' | 'generic';
+
+export interface ProjectInfo {
+  type: ProjectType;
+  name: string;
+  description?: string;
+  dependencies: string[];
+  devDependencies?: string[];
+  scripts?: Record<string, string>;
+  entryPoints: string[];
+}
+
+export async function detectProjectType(root: string): Promise<ProjectInfo> {
+  const absRoot = path.resolve(root);
+
+  // Check for Node.js (package.json)
+  const packageJsonPath = path.join(absRoot, 'package.json');
+  if (fs.existsSync(packageJsonPath)) {
+    return parseNodeProject(absRoot, packageJsonPath);
+  }
+
+  // Check for Python
+  const pyprojectPath = path.join(absRoot, 'pyproject.toml');
+  const setupPyPath = path.join(absRoot, 'setup.py');
+  const requirementsPath = path.join(absRoot, 'requirements.txt');
+  if (fs.existsSync(pyprojectPath) || fs.existsSync(setupPyPath) || fs.existsSync(requirementsPath)) {
+    return parsePythonProject(absRoot);
+  }
+
+  // Check for Rust (Cargo.toml)
+  const cargoPath = path.join(absRoot, 'Cargo.toml');
+  if (fs.existsSync(cargoPath)) {
+    return parseRustProject(absRoot, cargoPath);
+  }
+
+  // Check for Go (go.mod)
+  const goModPath = path.join(absRoot, 'go.mod');
+  if (fs.existsSync(goModPath)) {
+    return parseGoProject(absRoot, goModPath);
+  }
+
+  return parseGenericProject(absRoot);
+}
+
+function parseNodeProject(root: string, packageJsonPath: string): ProjectInfo {
+  const content = fs.readFileSync(packageJsonPath, 'utf-8');
+  const pkg = JSON.parse(content);
+  const deps = Object.keys(pkg.dependencies || {});
+  const devDeps = Object.keys(pkg.devDependencies || {});
+  const entryPoints: string[] = [];
+  if (pkg.main) entryPoints.push(pkg.main);
+  if (pkg.bin) {
+    if (typeof pkg.bin === 'string') entryPoints.push(pkg.bin);
+    else entryPoints.push(...Object.values(pkg.bin) as string[]);
+  }
+  return {
+    type: 'nodejs',
+    name: pkg.name || path.basename(root),
+    description: pkg.description,
+    dependencies: deps,
+    devDependencies: devDeps,
+    scripts: pkg.scripts,
+    entryPoints,
+  };
+}
+
+function parsePythonProject(root: string): ProjectInfo {
+  const name = path.basename(root);
+  const deps: string[] = [];
+  const entryPoints: string[] = [];
+  const reqPath = path.join(root, 'requirements.txt');
+  if (fs.existsSync(reqPath)) {
+    const content = fs.readFileSync(reqPath, 'utf-8');
+    for (const line of content.split('\n')) {
+      const trimmed = line.trim();
+      if (trimmed && !trimmed.startsWith('#')) {
+        const pkg = trimmed.split(/[=<>!]/)[0].trim();
+        if (pkg) deps.push(pkg);
+      }
+    }
+  }
+  for (const entry of ['main.py', 'app.py', '__main__.py']) {
+    if (fs.existsSync(path.join(root, entry))) entryPoints.push(entry);
+  }
+  return { type: 'python', name, dependencies: deps, entryPoints };
+}
+
+function parseRustProject(root: string, cargoPath: string): ProjectInfo {
+  const content = fs.readFileSync(cargoPath, 'utf-8');
+  const nameMatch = content.match(/^name\s*=\s*["']([^"']+)["']/m);
+  const descMatch = content.match(/^description\s*=\s*["']([^"']+)["']/m);
+  const deps: string[] = [];
+  const depsSection = content.match(/\[dependencies\]([\s\S]*?)(?:\[|$)/);
+  if (depsSection) {
+    const depLines = depsSection[1].match(/^(\w[\w-]*)\s*=/gm);
+    if (depLines) deps.push(...depLines.map(d => d.replace(/\s*=.*/, '')));
+  }
+  const entryPoints: string[] = [];
+  if (fs.existsSync(path.join(root, 'src/main.rs'))) entryPoints.push('src/main.rs');
+  if (fs.existsSync(path.join(root, 'src/lib.rs'))) entryPoints.push('src/lib.rs');
+  return {
+    type: 'rust',
+    name: nameMatch?.[1] || path.basename(root),
+    description: descMatch?.[1],
+    dependencies: deps,
+    entryPoints,
+  };
+}
+
+function parseGoProject(root: string, goModPath: string): ProjectInfo {
+  const content = fs.readFileSync(goModPath, 'utf-8');
+  const moduleMatch = content.match(/^module\s+(\S+)/m);
+  const deps: string[] = [];
+  const requireMatch = content.match(/require\s*\(([\s\S]*?)\)/);
+  if (requireMatch) {
+    const reqLines = requireMatch[1].match(/^\s*(\S+)\s+v/gm);
+    if (reqLines) deps.push(...reqLines.map(d => d.trim().split(/\s/)[0]));
+  }
+  const entryPoints: string[] = [];
+  if (fs.existsSync(path.join(root, 'main.go'))) entryPoints.push('main.go');
+  return {
+    type: 'go',
+    name: moduleMatch?.[1]?.split('/').pop() || path.basename(root),
+    dependencies: deps,
+    entryPoints,
+  };
+}
+
+function parseGenericProject(root: string): ProjectInfo {
+  const name = path.basename(root);
+  let description: string | undefined;
+  for (const readme of ['README.md', 'README.txt', 'README']) {
+    const readmePath = path.join(root, readme);
+    if (fs.existsSync(readmePath)) {
+      const content = fs.readFileSync(readmePath, 'utf-8');
+      const firstPara = content.split(/\n\n/)[0].replace(/^#.*\n/, '').trim();
+      if (firstPara) description = firstPara.slice(0, 200);
+      break;
+    }
+  }
+  return { type: 'generic', name, description, dependencies: [], entryPoints: [] };
+}
diff --git a/src/core/indexer/index.ts b/src/core/indexer/index.ts
new file mode 100644
index 0000000..37a07b3
--- /dev/null
+++ b/src/core/indexer/index.ts
@@ -0,0 +1,6 @@
+export { detectProjectType, type ProjectType, type ProjectInfo } from './detector';
+export { scanFiles, getDirectoryTree, type ScanOptions, type ScannedFile } from './scanner';
+export { mapRelationships, resolveImportPath, loadIndexState, saveIndexState, type ComponentNode, type MappedRelationship, type IndexState } from './mapper';
+export { generateArchitectureSummary, formatArchitectureAsMarkdown, type ArchitectureSummary } from './architecture';
+export { indexProject, type IndexOptions, type IndexResult } from './indexProject';
+export * from './parsers';
diff --git a/src/core/indexer/indexProject.ts b/src/core/indexer/indexProject.ts
new file mode 100644
index 0000000..6990809
--- /dev/null
+++ b/src/core/indexer/indexProject.ts
@@ -0,0 +1,246 @@
+import * as path from 'path';
+import { addNode, addEdge, listNodes, updateNode, removeNode } from '../store';
+import { detectProjectType, ProjectInfo } from './detector';
+import { scanFiles, ScannedFile } from './scanner';
+import { parseTypeScript, parsePython } from './parsers';
+import { mapRelationships, loadIndexState, saveIndexState, IndexState, ComponentNode } from './mapper';
+import { generateArchitectureSummary, formatArchitectureAsMarkdown } from './architecture';
+import { Node } from '../../types';
+
+export interface IndexOptions {
+  update?: boolean;
+  dryRun?: boolean;
+  maxDepth?: number;
+  language?: string;
+  ignore?: string[];
+}
+
+export interface IndexResult {
+  projectName: string;
+  projectType: string;
+  componentsCreated: number;
+  componentsUpdated: number;
+  componentsRemoved: number;
+  relationshipsCreated: number;
+  architectureNodeId: string | null;
+  files: string[];
+}
+
+export async function indexProject(root: string, options: IndexOptions = {}): Promise<IndexResult> {
+  const absRoot = path.resolve(root);
+  const projectInfo = await detectProjectType(absRoot);
+  const state = options.update ? loadIndexState(absRoot) : null;
+
+  // Filter extensions by language if specified
+  let extensions: string[] | undefined;
+  if (options.language) {
+    const langMap: Record<string, string[]> = {
+      ts: ['.ts', '.tsx'],
+      typescript: ['.ts', '.tsx'],
+      js: ['.js', '.jsx', '.mjs', '.cjs'],
+      javascript: ['.js', '.jsx', '.mjs', '.cjs'],
+      py: ['.py'],
+      python: ['.py'],
+    };
+    extensions = langMap[options.language.toLowerCase()];
+  }
+
+  // Scan files
+  const files = await scanFiles(absRoot, {
+    maxDepth: options.maxDepth,
+    ignore: options.ignore,
+    extensions,
+  });
+
+  if (options.dryRun) {
+    return {
+      projectName: projectInfo.name,
+      projectType: projectInfo.type,
+      componentsCreated: files.length,
+      componentsUpdated: 0,
+      componentsRemoved: 0,
+      relationshipsCreated: 0,
+      architectureNodeId: null,
+      files: files.map(f => f.relativePath),
+    };
+  }
+
+  // Track what we're creating
+  const newState: IndexState = {
+    projectPath: absRoot,
+    projectName: projectInfo.name,
+    lastIndexed: Date.now(),
+    fileHashes: {},
+    nodeIds: {},
+  };
+
+  const componentNodes: ComponentNode[] = [];
+  let created = 0;
+  let updated = 0;
+
+  // Process each file
+  for (const file of files) {
+    // Check if file changed (for incremental updates)
+    if (state && state.fileHashes[file.relativePath] === file.hash) {
+      // File unchanged, keep existing node
+      if (state.nodeIds[file.relativePath]) {
+        newState.fileHashes[file.relativePath] = file.hash;
+        newState.nodeIds[file.relativePath] = state.nodeIds[file.relativePath];
+        // Still need to add to componentNodes for relationship mapping
+        const existingNode = listNodes({ limit: 1 }).find(n => n.id === state.nodeIds[file.relativePath]);
+        if (existingNode) {
+          componentNodes.push({
+            node: existingNode,
+            filePath: file.relativePath,
+            imports: (existingNode.metadata?.imports as string[]) || [],
+          });
+        }
+      }
+      continue;
+    }
+
+    // Parse file based on extension
+    let parsed: { exports: any[]; imports: any[]; classes: any[]; functions: any[]; loc: number } | null = null;
+    try {
+      if (['.ts', '.tsx', '.js', '.jsx', '.mjs', '.cjs'].includes(file.extension)) {
+        parsed = await parseTypeScript(file.path);
+      } else if (file.extension === '.py') {
+        parsed = await parsePython(file.path);
+      }
+    } catch {
+      // Skip files that fail to parse
+      continue;
+    }
+
+    if (!parsed) continue;
+
+    // Create component title from file path
+    const fileName = path.basename(file.relativePath, file.extension);
+    const dirName = path.dirname(file.relativePath);
+    const title = dirName === '.' ? fileName : `${dirName}/${fileName}`;
+
+    // Build content summary
+    const exportNames = parsed.exports.map((e: any) => e.name || e).slice(0, 20);
+    const classNames = parsed.classes.map((c: any) => c.name);
+    const funcNames = parsed.functions.map((f: any) => f.name).slice(0, 10);
+
+    const contentParts: string[] = [];
+    if (exportNames.length) contentParts.push(`Exports: ${exportNames.join(', ')}`);
+    if (classNames.length) contentParts.push(`Classes: ${classNames.join(', ')}`);
+    if (funcNames.length) contentParts.push(`Functions: ${funcNames.join(', ')}`);
+    contentParts.push(`Lines: ${parsed.loc}`);
+
+    const content = contentParts.join('\n');
+    const imports = parsed.imports.map((i: any) => i.source || i.module);
+
+    // Check if node exists
+    const existingNodeId = state?.nodeIds[file.relativePath];
+    let node: Node;
+
+    if (existingNodeId) {
+      // Update existing
+      const updatedNode = await updateNode(existingNodeId, {
+        content,
+        metadata: {
+          filePath: file.relativePath,
+          extension: file.extension,
+          exports: exportNames,
+          imports,
+          loc: parsed.loc,
+          indexedAt: Date.now(),
+        },
+      });
+      if (updatedNode) {
+        node = updatedNode;
+        updated++;
+      } else {
+        continue;
+      }
+    } else {
+      // Create new
+      node = await addNode({
+        kind: 'component',
+        title,
+        content,
+        tags: [projectInfo.name, file.extension.slice(1), 'indexed'],
+        metadata: {
+          filePath: file.relativePath,
+          extension: file.extension,
+          exports: exportNames,
+          imports,
+          loc: parsed.loc,
+          indexedAt: Date.now(),
+        },
+      });
+      created++;
+    }
+
+    newState.fileHashes[file.relativePath] = file.hash;
+    newState.nodeIds[file.relativePath] = node.id;
+    componentNodes.push({ node, filePath: file.relativePath, imports });
+  }
+
+  // Remove nodes for deleted files
+  let removed = 0;
+  if (state) {
+    for (const [filePath, nodeId] of Object.entries(state.nodeIds)) {
+      if (!newState.nodeIds[filePath]) {
+        removeNode(nodeId, true);
+        removed++;
+      }
+    }
+  }
+
+  // Map relationships
+  const relationships = mapRelationships(componentNodes, absRoot);
+  let relCreated = 0;
+  for (const rel of relationships) {
+    try {
+      addEdge(rel.fromId, rel.toId, rel.type);
+      relCreated++;
+    } catch {
+      // Edge might already exist
+    }
+  }
+
+  // Create/update architecture summary node
+  let archNodeId: string | null = null;
+  const archTitle = `${projectInfo.name} Architecture`;
+  const existingArch = listNodes({ kind: 'component', tags: [projectInfo.name, 'architecture'] });
+
+  const summary = generateArchitectureSummary(absRoot, projectInfo, componentNodes.map(c => c.node));
+  const archContent = formatArchitectureAsMarkdown(summary);
+
+  if (existingArch.length > 0) {
+    await updateNode(existingArch[0].id, { content: archContent });
+    archNodeId = existingArch[0].id;
+  } else {
+    const archNode = await addNode({
+      kind: 'component',
+      title: archTitle,
+      content: archContent,
+      tags: [projectInfo.name, 'architecture', 'indexed'],
+      metadata: {
+        projectType: projectInfo.type,
+        techStack: summary.techStack,
+        componentCount: componentNodes.length,
+        indexedAt: Date.now(),
+      },
+    });
+    archNodeId = archNode.id;
+  }
+
+  // Save state
+  saveIndexState(absRoot, newState);
+
+  return {
+    projectName: projectInfo.name,
+    projectType: projectInfo.type,
+    componentsCreated: created,
+    componentsUpdated: updated,
+    componentsRemoved: removed,
+    relationshipsCreated: relCreated,
+    architectureNodeId: archNodeId,
+    files: files.map(f => f.relativePath),
+  };
+}
diff --git a/src/core/indexer/mapper.ts b/src/core/indexer/mapper.ts
new file mode 100644
index 0000000..0643406
--- /dev/null
+++ b/src/core/indexer/mapper.ts
@@ -0,0 +1,109 @@
+import * as path from 'path';
+import * as fs from 'fs';
+import { Node } from '../../types';
+
+export interface ComponentNode {
+  node: Node;
+  filePath: string;
+  imports: string[];
+}
+
+export interface MappedRelationship {
+  fromId: string;
+  toId: string;
+  fromPath: string;
+  toPath: string;
+  type: 'depends_on' | 'contains';
+}
+
+export function mapRelationships(components: ComponentNode[], projectRoot: string): MappedRelationship[] {
+  const relationships: MappedRelationship[] = [];
+  const pathToComponent = new Map<string, ComponentNode>();
+
+  // Build lookup map
+  for (const comp of components) {
+    pathToComponent.set(comp.filePath, comp);
+    // Also map without extension for JS/TS imports
+    const withoutExt = comp.filePath.replace(/\.(ts|tsx|js|jsx|mjs|cjs)$/, '');
+    pathToComponent.set(withoutExt, comp);
+  }
+
+  // Map import relationships
+  for (const comp of components) {
+    for (const importPath of comp.imports) {
+      const resolved = resolveImportPath(importPath, comp.filePath, projectRoot);
+      if (resolved) {
+        const target = pathToComponent.get(resolved) || pathToComponent.get(resolved.replace(/\.(ts|tsx|js|jsx)$/, ''));
+        if (target && target.node.id !== comp.node.id) {
+          relationships.push({
+            fromId: comp.node.id,
+            toId: target.node.id,
+            fromPath: comp.filePath,
+            toPath: target.filePath,
+            type: 'depends_on',
+          });
+        }
+      }
+    }
+  }
+
+  return relationships;
+}
+
+export function resolveImportPath(importSource: string, fromFile: string, projectRoot: string): string | null {
+  // Skip external packages
+  if (!importSource.startsWith('.') && !importSource.startsWith('/')) {
+    return null;
+  }
+
+  const fromDir = path.dirname(fromFile);
+  let resolved: string;
+
+  if (importSource.startsWith('.')) {
+    resolved = path.resolve(fromDir, importSource);
+  } else {
+    resolved = path.resolve(projectRoot, importSource);
+  }
+
+  // Try with various extensions
+  const extensions = ['.ts', '.tsx', '.js', '.jsx', '.mjs', '/index.ts', '/index.js'];
+  for (const ext of extensions) {
+    const withExt = resolved + ext;
+    if (fs.existsSync(withExt)) {
+      return path.relative(projectRoot, withExt);
+    }
+  }
+
+  // Check if it exists as-is
+  if (fs.existsSync(resolved)) {
+    return path.relative(projectRoot, resolved);
+  }
+
+  return null;
+}
+
+export interface IndexState {
+  projectPath: string;
+  projectName: string;
+  lastIndexed: number;
+  fileHashes: Record<string, string>;
+  nodeIds: Record<string, string>;
+}
+
+const STATE_FILE = '.cortex-index.json';
+
+export function loadIndexState(projectRoot: string): IndexState | null {
+  const statePath = path.join(projectRoot, STATE_FILE);
+  if (!fs.existsSync(statePath)) return null;
+  try {
+    const content = fs.readFileSync(statePath, 'utf-8');
+    return JSON.parse(content);
+  } catch {
+    return null;
+  }
+}
+
+export function saveIndexState(projectRoot: string, state: IndexState): void {
+  const statePath = path.join(projectRoot, STATE_FILE);
+  fs.writeFileSync(statePath, JSON.stringify(state, null, 2));
+}
diff --git a/src/core/indexer/parsers/index.ts b/src/core/indexer/parsers/index.ts
new file mode 100644
index 0000000..a85903d
--- /dev/null
+++ b/src/core/indexer/parsers/index.ts
@@ -0,0 +1,2 @@
+export { parseTypeScript, type ParsedTSFile, type ExportInfo, type ImportInfo, type ClassInfo, type FunctionInfo } from './typescript';
+export { parsePython, type ParsedPyFile, type PyImport, type PyClass, type PyFunction } from './python';
diff --git a/src/core/indexer/parsers/python.ts b/src/core/indexer/parsers/python.ts
new file mode 100644
index 0000000..8c12fe3
--- /dev/null
+++ b/src/core/indexer/parsers/python.ts
@@ -0,0 +1,120 @@
+import * as fs from 'fs';
+
+export interface ParsedPyFile {
+  filePath: string;
+  language: 'python';
+  imports: PyImport[];
+  classes: PyClass[];
+  functions: PyFunction[];
+  exports: string[];
+  loc: number;
+}
+
+export interface PyImport {
+  module: string;
+  names: string[];
+  isRelative: boolean;
+  line: number;
+}
+
+export interface PyClass {
+  name: string;
+  bases: string[];
+  methods: string[];
+  decorators: string[];
+  line: number;
+}
+
+export interface PyFunction {
+  name: string;
+  isAsync: boolean;
+  decorators: string[];
+  line: number;
+}
+
+export async function parsePython(filePath: string): Promise<ParsedPyFile> {
+  const content = fs.readFileSync(filePath, 'utf-8');
+  const lines = content.split('\n');
+
+  const imports: PyImport[] = [];
+  const classes: PyClass[] = [];
+  const functions: PyFunction[] = [];
+  let exports: string[] = [];
+
+  let currentDecorators: string[] = [];
+
+  for (let i = 0; i < lines.length; i++) {
+    const line = lines[i];
+    const lineNum = i + 1;
+
+    // __all__ exports
+    const allMatch = line.match(/^__all__\s*=\s*\[([^\]]+)\]/);
+    if (allMatch) {
+      exports = allMatch[1].match(/['"](\w+)['"]/g)?.map(s => s.slice(1, -1)) || [];
+    }
+
+    // Decorators
+    const decoMatch = line.match(/^@(\w+)/);
+    if (decoMatch) {
+      currentDecorators.push(decoMatch[1]);
+      continue;
+    }
+
+    // Import statements
+    const importMatch = line.match(/^import\s+(\S+)/);
+    if (importMatch) {
+      imports.push({ module: importMatch[1], names: [importMatch[1]], isRelative: false, line: lineNum });
+      currentDecorators = [];
+      continue;
+    }
+
+    const fromMatch = line.match(/^from\s+(\S+)\s+import\s+(.+)/);
+    if (fromMatch) {
+      const module = fromMatch[1];
+      const names = fromMatch[2].split(',').map(n => n.trim().split(/\s+as\s+/)[0]).filter(Boolean);
+      imports.push({ module, names, isRelative: module.startsWith('.'), line: lineNum });
+      currentDecorators = [];
+      continue;
+    }
+
+    // Class definitions
+    const classMatch = line.match(/^class\s+(\w+)(?:\(([^)]*)\))?:/);
+    if (classMatch) {
+      const className = classMatch[1];
+      const bases = classMatch[2]?.split(',').map(b => b.trim()).filter(Boolean) || [];
+      const methods: string[] = [];
+
+      // Find methods
+      for (let j = i + 1; j < lines.length; j++) {
+        const methodLine = lines[j];
+        if (methodLine.match(/^\S/) && !methodLine.match(/^\s*#/) && !methodLine.match(/^\s*$/)) break;
+        const methodMatch = methodLine.match(/^\s+(?:async\s+)?def\s+(\w+)/);
+        if (methodMatch) methods.push(methodMatch[1]);
+      }
+
+      classes.push({ name: className, bases, methods, decorators: currentDecorators, line: lineNum });
+      currentDecorators = [];
+      continue;
+    }
+
+    // Function definitions (top-level only)
+    const funcMatch = line.match(/^(async\s+)?def\s+(\w+)/);
+    if (funcMatch) {
+      functions.push({
+        name: funcMatch[2],
+        isAsync: !!funcMatch[1],
+        decorators: currentDecorators,
+        line: lineNum,
+      });
+      currentDecorators = [];
+      continue;
+    }
+
+    // Reset decorators if we hit a non-decorator, non-function/class line
+    if (!line.match(/^\s*$/) && !line.match(/^\s*#/)) {
+      currentDecorators = [];
+    }
+  }
+
+  return { filePath, language: 'python', imports, classes, functions, exports, loc: lines.length };
+}
diff --git a/src/core/indexer/parsers/typescript.ts b/src/core/indexer/parsers/typescript.ts
new file mode 100644
index 0000000..375346f
--- /dev/null
+++ b/src/core/indexer/parsers/typescript.ts
@@ -0,0 +1,132 @@
+import * as fs from 'fs';
+import * as path from 'path';
+
+export interface ParsedTSFile {
+  filePath: string;
+  language: 'typescript' | 'javascript';
+  exports: ExportInfo[];
+  imports: ImportInfo[];
+  classes: ClassInfo[];
+  functions: FunctionInfo[];
+  loc: number;
+}
+
+export interface ExportInfo {
+  name: string;
+  kind: 'function' | 'class' | 'interface' | 'type' | 'const' | 'default' | 'enum';
+  line: number;
+}
+
+export interface ImportInfo {
+  source: string;
+  names: string[];
+  line: number;
+}
+
+export interface ClassInfo {
+  name: string;
+  extends?: string;
+  implements: string[];
+  methods: string[];
+  isExported: boolean;
+  line: number;
+}
+
+export interface FunctionInfo {
+  name: string;
+  isAsync: boolean;
+  isExported: boolean;
+  line: number;
+}
+
+export async function parseTypeScript(filePath: string): Promise<ParsedTSFile> {
+  const content = fs.readFileSync(filePath, 'utf-8');
+  const ext = path.extname(filePath).toLowerCase();
+  const language = ext === '.ts' || ext === '.tsx' ? 'typescript' : 'javascript';
+  return parseContent(filePath, content, language);
+}
+
+function parseContent(filePath: string, content: string, language: 'typescript' | 'javascript'): ParsedTSFile {
+  const lines = content.split('\n');
+  const exports: ExportInfo[] = [];
+  const imports: ImportInfo[] = [];
+  const classes: ClassInfo[] = [];
+  const functions: FunctionInfo[] = [];
+
+  // Parse imports
+  const importRegex = /^import\s+.*?\s+from\s+['"]([^'"]+)['"]/gm;
+  let match: RegExpExecArray | null;
+  while ((match = importRegex.exec(content)) !== null) {
+    const line = content.slice(0, match.index).split('\n').length;
+    const clause = match[0].replace(/^import\s+/, '').replace(/\s+from.*/, '');
+    const names: string[] = [];
+    const namedMatch = clause.match(/\{([^}]+)\}/);
+    if (namedMatch) names.push(...namedMatch[1].split(',').map(n => n.trim().split(/\s+as\s+/)[0]).filter(Boolean));
+    const defaultMatch = clause.match(/^(\w+)/);
+    if (defaultMatch && !clause.startsWith('{') && !clause.startsWith('*')) names.push(defaultMatch[1]);
+    if (clause.includes('*')) names.push('*');
+    imports.push({ source: match[1], names, line });
+  }
+
+  // Parse line by line
+  for (let i = 0; i < lines.length; i++) {
+    const line = lines[i];
+    const lineNum = i + 1;
+
+    // Export const/let
+    const constMatch = line.match(/^export\s+(const|let|var)\s+(\w+)/);
+    if (constMatch) exports.push({ name: constMatch[2], kind: 'const', line: lineNum });
+
+    // Export default
+    if (line.match(/^export\s+default\s+/)) {
+      const m = line.match(/^export\s+default\s+(?:class|function)?\s*(\w+)?/);
+      exports.push({ name: m?.[1] || 'default', kind: 'default', line: lineNum });
+    }
+
+    // Export type/interface
+    const typeMatch = line.match(/^export\s+(type|interface)\s+(\w+)/);
+    if (typeMatch) exports.push({ name: typeMatch[2], kind: typeMatch[1] as 'type' | 'interface', line: lineNum });
+
+    // Export enum
+    const enumMatch = line.match(/^export\s+enum\s+(\w+)/);
+    if (enumMatch) exports.push({ name: enumMatch[1], kind: 'enum', line: lineNum });
+
+    // Classes
+    const classMatch = line.match(/^(export\s+)?(abstract\s+)?class\s+(\w+)(?:\s+extends\s+(\w+))?(?:\s+implements\s+([^{]+))?/);
+    if (classMatch) {
+      const isExported = !!classMatch[1];
+      const className = classMatch[3];
+      const methods: string[] = [];
+      for (let j = i + 1; j < lines.length && j < i + 100; j++) {
+        if (lines[j].match(/^\s*\}/) && !lines[j].match(/^\s*\}\s*\)/)) break;
+        const methodMatch = lines[j].match(/^\s+(async\s+)?(\w+)\s*\(/);
+        if (methodMatch && methodMatch[2] !== 'constructor') methods.push(methodMatch[2]);
+      }
+      classes.push({
+        name: className,
+        extends: classMatch[4],
+        implements: classMatch[5]?.split(',').map(s => s.trim()).filter(Boolean) || [],
+        methods,
+        isExported,
+        line: lineNum,
+      });
+      if (isExported) exports.push({ name: className, kind: 'class', line: lineNum });
+    }
+
+    // Functions
+    const funcMatch = line.match(/^(export\s+)?(async\s+)?function\s+(\w+)/);
+    if (funcMatch) {
+      const isExported = !!funcMatch[1];
+      functions.push({ name: funcMatch[3], isAsync: !!funcMatch[2], isExported, line: lineNum });
+      if (isExported) exports.push({ name: funcMatch[3], kind: 'function', line: lineNum });
+    }
+
+    // Arrow function exports
+    const arrowMatch = line.match(/^export\s+(const|let)\s+(\w+)\s*=\s*(async\s+)?[\(]/);
+    if (arrowMatch) {
+      functions.push({ name: arrowMatch[2], isAsync: !!arrowMatch[3], isExported: true, line: lineNum });
+    }
+  }
+
+  return { filePath, language, exports, imports, classes, functions, loc: lines.length };
+}
diff --git a/src/core/indexer/scanner.ts b/src/core/indexer/scanner.ts
new file mode 100644
index 0000000..771565d
--- /dev/null
+++ b/src/core/indexer/scanner.ts
@@ -0,0 +1,108 @@
+import * as fs from 'fs';
+import * as path from 'path';
+import * as crypto from 'crypto';
+
+export interface ScanOptions {
+  maxDepth?: number;
+  ignore?: string[];
+  extensions?: string[];
+}
+
+export interface ScannedFile {
+  path: string;
+  relativePath: string;
+  extension: string;
+  size: number;
+  hash: string;
+}
+
+const DEFAULT_IGNORE = [
+  'node_modules', '.git', 'dist', 'build', '__pycache__', '.pytest_cache',
+  '.mypy_cache', '.env', 'coverage', '.next', '.nuxt', 'target', 'vendor',
+  '.idea', '.vscode', '.DS_Store', 'Thumbs.db',
+];
+
+const CODE_EXTENSIONS = [
+  '.ts', '.tsx', '.js', '.jsx', '.mjs', '.cjs',
+  '.py', '.rs', '.go', '.java', '.kt', '.c', '.cpp', '.h', '.hpp',
+  '.cs', '.rb', '.php', '.swift', '.vue', '.svelte',
+];
+
+export async function scanFiles(root: string, options: ScanOptions = {}): Promise<ScannedFile[]> {
+  const absRoot = path.resolve(root);
+  const maxDepth = options.maxDepth ?? 10;
+  const ignorePatterns = [...DEFAULT_IGNORE, ...(options.ignore || [])];
+  const extensions = options.extensions || CODE_EXTENSIONS;
+  const files: ScannedFile[] = [];
+
+  function shouldIgnore(name: string): boolean {
+    for (const pattern of ignorePatterns) {
+      if (pattern.startsWith('*.')) {
+        if (name.endsWith(pattern.slice(1))) return true;
+      } else if (name === pattern) return true;
+    }
+    return false;
+  }
+
+  function walk(dir: string, depth: number): void {
+    if (depth > maxDepth) return;
+    let entries: fs.Dirent[];
+    try {
+      entries = fs.readdirSync(dir, { withFileTypes: true });
+    } catch { return; }
+
+    for (const entry of entries) {
+      if (shouldIgnore(entry.name)) continue;
+      const fullPath = path.join(dir, entry.name);
+
+      if (entry.isDirectory()) {
+        walk(fullPath, depth + 1);
+      } else if (entry.isFile()) {
+        const ext = path.extname(entry.name).toLowerCase();
+        if (extensions.includes(ext)) {
+          try {
+            const stat = fs.statSync(fullPath);
+            const content = fs.readFileSync(fullPath);
+            files.push({
+              path: fullPath,
+              relativePath: path.relative(absRoot, fullPath),
+              extension: ext,
+              size: stat.size,
+              hash: crypto.createHash('md5').update(content).digest('hex'),
+            });
+          } catch { /* skip */ }
+        }
+      }
+    }
+  }
+
+  walk(absRoot, 0);
+  return files;
+}
+
+export function getDirectoryTree(root: string, maxDepth: number = 3): string {
+  const absRoot = path.resolve(root);
+  const lines: string[] = [path.basename(absRoot) + '/'];
+
+  function walk(dir: string, prefix: string, depth: number): void {
+    if (depth > maxDepth) return;
+    let entries: fs.Dirent[];
+    try { entries = fs.readdirSync(dir, { withFileTypes: true }); } catch { return; }
+
+    const filtered = entries.filter(e => !DEFAULT_IGNORE.includes(e.name) && !e.name.startsWith('.'));
+    const dirs = filtered.filter(e => e.isDirectory()).sort((a, b) => a.name.localeCompare(b.name));
+    const files = filtered.filter(e => e.isFile()).sort((a, b) => a.name.localeCompare(b.name));
+    const sorted = [...dirs, ...files];
+
+    sorted.forEach((entry, i) => {
+      const isLast = i === sorted.length - 1;
+      lines.push(prefix + (isLast ? '└── ' : '├── ') + entry.name + (entry.isDirectory() ? '/' : ''));
+      if (entry.isDirectory()) {
+        walk(path.join(dir, entry.name), prefix + (isLast ? '    ' : '│   '), depth + 1);
+      }
+    });
+  }
+
+  walk(absRoot, '', 0);
+  return lines.join('\n');
+}
diff --git a/src/mcp/index.ts b/src/mcp/index.ts
index 63b8955..703c028 100644
--- a/src/mcp/index.ts
+++ b/src/mcp/index.ts
@@ -590,6 +590,57 @@ server.tool(
   }
 );
 
+// --- memory_index ---
+import { indexProject } from '../core/indexer';
+
+server.tool(
+  'memory_index',
+  'Index a codebase to create component nodes. Scans files, extracts exports/imports, and maps relationships.',
+  {
+    path: z.string().optional().describe('Path to index (default: current directory)'),
+    update: z.boolean().optional().describe('Only update changed files (incremental)'),
+    language: z.string().optional().describe('Only index specific language (ts, js, py)'),
+    maxDepth: z.number().optional().describe('Maximum directory depth (default: 10)'),
+  },
+  async ({ path: inputPath, update, language, maxDepth }) => {
+    const result = await indexProject(inputPath || '.', {
+      update,
+      language,
+      maxDepth,
+    });
+    return { content: [{ type: 'text' as const, text: serialize(result) }] };
+  }
+);
+
+// --- memory_components ---
+server.tool(
+  'memory_components',
+  'List indexed components for a project',
+  {
+    project: z.string().optional().describe('Project name to filter by'),
+    limit: z.number().optional().describe('Max results (default: 50)'),
+  },
+  async ({ project, limit }) => {
+    const tags = project ? [project, 'indexed'] : ['indexed'];
+    const components = listNodes({ kind: 'component' as NodeKind, tags, limit: limit || 50 });
+    return {
+      content: [{
+        type: 'text' as const,
+        text: serialize({
+          count: components.length,
+          components: components.map(c => ({
+            id: c.id,
+            title: c.title,
+            filePath: c.metadata?.filePath,
+            exports: (c.metadata?.exports as string[])?.length || 0,
+            loc: c.metadata?.loc,
+          })),
+        }),
+      }],
+    };
+  }
+);
+
 async function main() {
   const transport = new StdioServerTransport();
   await server.connect(transport);