# Milestone 4: Codebase Indexing

## Overview

Automatically scan and index project structure, creating component nodes for modules, services, and architectural patterns. Claude understands your codebase from day one.

## Motivation

- New projects require extensive explanation to Claude
- Architecture decisions are scattered across files
- Component relationships aren't captured anywhere
- Supermemory's `/index` command is highly valued

## Features

### 4.1 Project Scanner

```bash
# Index current project
cortex index .

# Index specific directory
cortex index ./src

# Re-index (update existing)
cortex index . --update

# Index with specific depth
cortex index . --depth 3
```

### 4.2 Auto-Detection

Detect project type and extract relevant info:

| Project Type | Detection | Extracts |
|--------------|-----------|----------|
| Node.js | `package.json` | Dependencies, scripts, name |
| Python | `pyproject.toml`, `setup.py` | Dependencies, entry points |
| Rust | `Cargo.toml` | Crates, features |
| Go | `go.mod` | Modules, dependencies |
| Generic | `README.md` | Description, setup |

### 4.3 Component Extraction

Create nodes for discovered components:

```typescript
interface IndexedComponent {
  kind: 'component';
  title: string;           // e.g., "UserService"
  content: string;         // Description + key exports
  tags: string[];          // ['backend', 'service', 'auth']
  metadata: {
    filePath: string;
    language: string;
    exports: string[];
    imports: string[];
    loc: number;
  };
}
```

### 4.4 Relationship Mapping

Auto-create edges based on imports/dependencies:

```typescript
// File A imports from File B
addEdge(componentA.id, componentB.id, 'depends_on');

// Directory contains files
addEdge(directoryNode.id, fileNode.id, 'contains');

// Module implements interface
addEdge(impl.id, interface.id, 'implements');
```

### 4.5 Architecture Summary

Generate high-level architecture node:

```typescript
const architectureNode = {
  kind: 'component',
  title: `${projectName} Architecture`,
  content: `
## Overview
${projectDescription}

## Tech Stack
- Runtime: ${runtime}
- Framework: ${framework}
- Database: ${database}

## Key Components
${components.map(c => `- **${c.title}**: ${c.summary}`).join('\n')}

## Directory Structure
${directoryTree}
`,
  tags: ['architecture', 'index', projectName],
};
```

### 4.6 Incremental Updates

Track indexed files and only re-process changes:

```typescript
interface IndexState {
  projectPath: string;
  lastIndexed: number;
  fileHashes: Record<string, string>;  // path -> content hash
  nodeIds: Record<string, string>;     // path -> node ID
}
```

## Implementation

### Scanner Architecture

```typescript
// src/core/indexer/index.ts
export async function indexProject(root: string, options: IndexOptions): Promise<IndexResult> {
  // Detect project type
  const projectType = await detectProjectType(root);

  // Load existing index state
  const state = await loadIndexState(root);

  // Scan files
  const files = await scanFiles(root, {
    ignore: [...DEFAULT_IGNORE, ...options.ignore],
    maxDepth: options.depth,
  });

  // Process each file
  const components: IndexedComponent[] = [];
  for (const file of files) {
    if (shouldSkip(file, state)) continue;

    const component = await extractComponent(file, projectType);
    if (component) {
      components.push(component);
    }
  }

  // Create/update nodes
  const nodes = await upsertComponents(components, state);

  // Map relationships
  await mapRelationships(nodes, files);

  // Generate architecture summary
  await generateArchitectureSummary(root, projectType, nodes);

  // Save state
  await saveIndexState(root, state);

  return { indexed: nodes.length, relationships: edges.length };
}
```

### Language Parsers

```typescript
// src/core/indexer/parsers/typescript.ts
export async function parseTypeScript(file: string): Promise<ParsedFile> {
  // Use TypeScript compiler API or tree-sitter
  const ast = ts.createSourceFile(file, content, ts.ScriptTarget.Latest);

  return {
    exports: extractExports(ast),
    imports: extractImports(ast),
    classes: extractClasses(ast),
    functions: extractFunctions(ast),
    interfaces: extractInterfaces(ast),
  };
}

// Parsers for: JavaScript, Python, Rust, Go, etc.
```

### Ignore Patterns

```typescript
const DEFAULT_IGNORE = [
  'node_modules',
  '.git',
  'dist',
  'build',
  '__pycache__',
  '.env*',
  '*.min.js',
  '*.map',
  'coverage',
  '.next',
  'target',  // Rust
  'vendor',  // Go
];
```

## CLI Commands

| Command | Description |
|---------|-------------|
| `cortex index [path]` | Index project at path |
| `cortex index --update` | Update existing index |
| `cortex index --dry-run` | Preview what would be indexed |
| `cortex index --depth <n>` | Limit directory depth |
| `cortex index --lang <lang>` | Only index specific language |

## MCP Tools

```typescript
memory_index      // Index current project
memory_reindex    // Force re-index
memory_components // List indexed components
```

## Testing

- [ ] Detects Node.js, Python, Rust, Go projects
- [ ] Creates component nodes for modules
- [ ] Maps import relationships correctly
- [ ] Respects .gitignore patterns
- [ ] Incremental update only processes changes
- [ ] Architecture summary is accurate
- [ ] Performance: <30s for 10k file project

## Acceptance Criteria

- [ ] `cortex index .` creates meaningful component nodes
- [ ] Relationships reflect actual code dependencies
- [ ] Architecture summary provides useful overview
- [ ] Incremental updates are fast
- [ ] Works with monorepos
- [ ] MCP tool enables Claude to trigger indexing

## Estimated Effort

- Project detection: 2 hours
- File scanner: 3 hours
- TypeScript parser: 4 hours
- Python parser: 3 hours
- Relationship mapping: 4 hours
- Architecture summary: 3 hours
- Incremental updates: 3 hours
- Testing: 3 hours
- **Total: ~25 hours**

## Dependencies

- None (enhances Milestone 3 but independent)

## References

- [tree-sitter](https://tree-sitter.github.io/tree-sitter/) for parsing
- [Sourcebot architecture](https://github.com/sourcebot-dev/sourcebot)