🔮 CodeGraph

Supercharge Claude Code with Semantic Code Intelligence

30% fewer tokens • 25% fewer tool calls • 100% local

Get Started

npx @mduenas/codegraph

Interactive installer configures Claude Code automatically

🚀 Why CodeGraph?

When you ask Claude Code to work on a complex task, it spawns Explore agents that scan your codebase using grep, glob, and file reads. These agents consume tokens with every tool call.

CodeGraph gives those agents a semantic knowledge graph — pre-indexed symbol relationships, call graphs, and code structure. Instead of scanning files, agents query the graph instantly.

📊 Benchmark Results

We ran the same complex task 3 times with and without CodeGraph:

| Metric | Without CodeGraph | With CodeGraph | Improvement | |--------|-------------------|----------------|-------------| | Explore tokens | 157.8k | 111.7k | 29% fewer | | Per-agent tokens | 74.0k | 46.4k | 37% fewer | | Tool calls | 60 | 45 | 25% fewer | | Main context usage | 28.7% | 24.0% | 4.7% less |

With CodeGraph: | Test | Agents | Tool Uses | Explore Tokens | Plan Tokens | Time | |------|--------|-----------|----------------|-------------|------| | 1 | 3 | 54 | 149.7k | 76.4k | 1m 43s | | 2 | 2 | 41 | 102.1k | 74.8k | 1m 29s | | 3 | 2 | 40 | 83.3k | 63.3k | 1m 25s | | Avg | 2.3 | 45 | 111.7k | 71.5k | 1m 32s |

Without CodeGraph: | Test | Agents | Tool Uses | Explore Tokens | Plan Tokens | Time | |------|--------|-----------|----------------|-------------|------| | 1 | 3 | 74 | 177.3k | 80.5k | 1m 54s | | 2 | 2 | 55 | 149.3k | 64.0k | 1m 27s | | 3 | 2 | 51 | 146.7k | 62.3k | 1m 17s | | Avg | 2.3 | 60 | 157.8k | 68.9k | 1m 33s |

🔄 How It Works

┌─────────────────────────────────────────────────────────────────┐
│                        Claude Code                               │
│                                                                  │
│  "Implement user authentication"                                 │
│           │                                                      │
│           ▼                                                      │
│  ┌─────────────────┐      ┌─────────────────┐                   │
│  │  Explore Agent  │ ──── │  Explore Agent  │                   │
│  └────────┬────────┘      └────────┬────────┘                   │
│           │                        │                             │
└───────────┼────────────────────────┼─────────────────────────────┘
            │                        │
            ▼                        ▼
┌───────────────────────────────────────────────────────────────────┐
│                     CodeGraph MCP Server                          │
│  ┌─────────────┐  ┌─────────────┐  ┌─────────────┐               │
│  │   Search    │  │   Callers   │  │   Context   │               │
│  │  "auth"     │  │  "login()"  │  │  for task   │               │
│  └──────┬──────┘  └──────┬──────┘  └──────┬──────┘               │
│         │                │                │                       │
│         └────────────────┼────────────────┘                       │
│                          ▼                                        │
│              ┌───────────────────────┐                            │
│              │   SQLite Graph DB     │                            │
│              │   • 387 symbols       │                            │
│              │   • 1,204 edges       │                            │
│              │   • Instant lookups   │                            │
│              └───────────────────────┘                            │
└───────────────────────────────────────────────────────────────────┘

Without CodeGraph: Explore agents use grep, glob, and Read to scan files → many API calls, high token usage

With CodeGraph: Explore agents query the graph via MCP tools → instant results, local processing, fewer tokens

✨ Key Features

🧠 Smart Context Building

One tool call returns everything Claude needs—entry points, related symbols, and code snippets. No more expensive exploration agents.

🔍 Semantic Search

Find code by meaning, not just text. Search for "authentication" and find login, validateToken, AuthService—even with different naming conventions.

📈 Impact Analysis

Know exactly what breaks before you change it. Trace callers, callees, and the full impact radius of any symbol.

🌍 15+ Languages

TypeScript, JavaScript, Python, Go, Rust, Java, C#, PHP, Ruby, C, C++, Swift, Kotlin—all with the same API.

🔒 100% Local

No data leaves your machine. No API keys. No external services. Everything runs on your local SQLite database.

⚡ Always Fresh

Git hooks automatically sync the index on every commit. Your code intelligence is always up to date.

🎯 Quick Start

1. Run the Installer

npx @mduenas/codegraph

The interactive installer will:

• Configure the MCP server in ~/.claude.json
• Set up auto-allow permissions for CodeGraph tools
• Add global instructions to ~/.claude/CLAUDE.md (teaches Claude how to use CodeGraph)
• Optionally initialize your current project

2. Restart Claude Code

Restart Claude Code for the MCP server to load.

3. Initialize Projects

For each project you want to use CodeGraph with:

cd your-project
codegraph init -i

That's it! Claude Code will now use CodeGraph tools automatically when a .codegraph/ directory exists.

If you prefer manual configuration:

Install globally:

npm install -g @mduenas/codegraph

Add to ~/.claude.json:

{
  "mcpServers": {
    "codegraph": {
      "type": "stdio",
      "command": "codegraph",
      "args": ["serve", "--mcp"]
    }
  }
}

Add to ~/.claude/settings.json (optional, for auto-allow):

{
  "permissions": {
    "allow": [
      "mcp__codegraph__codegraph_search",
      "mcp__codegraph__codegraph_context",
      "mcp__codegraph__codegraph_callers",
      "mcp__codegraph__codegraph_callees",
      "mcp__codegraph__codegraph_impact",
      "mcp__codegraph__codegraph_node",
      "mcp__codegraph__codegraph_status"
    ]
  }
}

The installer automatically adds these instructions to ~/.claude/CLAUDE.md. This is provided here for reference:

## CodeGraph

CodeGraph builds a semantic knowledge graph of codebases for faster, smarter code exploration.

### If `.codegraph/` exists in the project

**Use codegraph tools for faster exploration.** These tools provide instant lookups via the code graph instead of scanning files:

| Tool | Use For |
|------|---------|
| `codegraph_search` | Find symbols by name (functions, classes, types) |
| `codegraph_context` | Get relevant code context for a task |
| `codegraph_callers` | Find what calls a function |
| `codegraph_callees` | Find what a function calls |
| `codegraph_impact` | See what's affected by changing a symbol |
| `codegraph_node` | Get details + source code for a symbol |

**When spawning Explore agents in a codegraph-enabled project:**

Tell the Explore agent to use codegraph tools for faster exploration.

**For quick lookups in the main session:**
- Use `codegraph_search` instead of grep for finding symbols
- Use `codegraph_callers`/`codegraph_callees` to trace code flow
- Use `codegraph_impact` before making changes to see what's affected

### If `.codegraph/` does NOT exist

At the start of a session, ask the user if they'd like to initialize CodeGraph:

"I notice this project doesn't have CodeGraph initialized. Would you like me to run `codegraph init -i` to build a code knowledge graph?"

📋 Requirements

• Node.js >= 18.0.0

💻 CLI Usage

codegraph                   # Run interactive installer
codegraph install           # Run interactive installer (explicit)
codegraph init [path]       # Initialize in a project
codegraph index [path]      # Full index
codegraph sync [path]       # Incremental update
codegraph status [path]     # Show statistics
codegraph query <search>    # Search symbols
codegraph context <task>    # Build context for AI
codegraph hooks install     # Install git auto-sync hook
codegraph serve --mcp       # Start MCP server

📖 CLI Commands

codegraph / codegraph install

Run the interactive installer for Claude Code integration. Configures MCP server and permissions automatically.

codegraph                         # Run installer (when no args)
codegraph install                 # Run installer (explicit)
npx @mduenas/codegraph       # Run via npx (no global install needed)

The installer will:

1. Ask for installation location (global ~/.claude or local ./.claude)
2. Configure the MCP server in claude.json
3. Optionally set up auto-allow permissions
4. Add global instructions to ~/.claude/CLAUDE.md (teaches Claude how to use CodeGraph)
5. For local installs: initialize and index the current project

codegraph init [path]

Initialize CodeGraph in a project directory. Creates a .codegraph/ directory with the database and configuration.

codegraph init                    # Initialize in current directory
codegraph init /path/to/project   # Initialize in specific directory
codegraph init --index            # Initialize and immediately index
codegraph init --no-hooks         # Skip git hook installation

codegraph index [path]

Index all files in the project. Extracts functions, classes, methods, and their relationships.

codegraph index                   # Index current directory
codegraph index --force           # Force full re-index
codegraph index --quiet           # Suppress progress output

codegraph sync [path]

Incrementally sync changes since the last index. Only processes added, modified, or removed files.

codegraph sync                    # Sync current directory
codegraph sync --quiet            # Suppress output

codegraph status [path]

Show index status and statistics.

codegraph status

Output includes:

• Files indexed, nodes, edges
• Nodes by kind (functions, classes, methods, etc.)
• Files by language
• Pending changes (if any)
• Git hook status

codegraph query <search>

Search for symbols in the codebase by name.

codegraph query "authenticate"           # Search for symbols
codegraph query "User" --kind class      # Filter by kind
codegraph query "process" --limit 20     # Limit results
codegraph query "validate" --json        # Output as JSON

codegraph context <task>

Build relevant code context for a task. Uses semantic search to find entry points, then expands through the graph to find related code.

codegraph context "fix checkout bug"
codegraph context "add user authentication" --format json
codegraph context "refactor payment service" --max-nodes 30

codegraph hooks

Manage git hooks for automatic syncing.

codegraph hooks install    # Install post-commit hook
codegraph hooks remove     # Remove hook
codegraph hooks status     # Check if hook is installed

codegraph serve

Start CodeGraph as an MCP server for AI assistants.

codegraph serve                          # Show MCP configuration help
codegraph serve --mcp                    # Start MCP server (stdio)
codegraph serve --mcp --path /project    # Specify project path

🔌 MCP Tools Reference

When running as an MCP server, CodeGraph exposes these tools to AI assistants. These tools are designed to be used by Claude's Explore agents for faster, more efficient codebase exploration.

codegraph_context

Build context for a specific task. Good for focused queries.

codegraph_context(task: "fix checkout validation bug", maxNodes: 20)

codegraph_search

Quick symbol search by name. Returns locations only.

codegraph_search(query: "UserService", kind: "class", limit: 10)

codegraph_callers / codegraph_callees

Find what calls a function, or what a function calls.

codegraph_callers(symbol: "validatePayment", limit: 20)
codegraph_callees(symbol: "processOrder", limit: 20)

codegraph_impact

Analyze what code would be affected by changing a symbol.

codegraph_impact(symbol: "UserService", depth: 2)

codegraph_node

Get details about a specific symbol. Use includeCode: true only when needed.

codegraph_node(symbol: "authenticate", includeCode: true)

codegraph_status

Check index health and statistics.

How It Works With Claude Code

Claude's Explore agents use these tools instead of grep/glob/Read for faster exploration:

| Without CodeGraph | With CodeGraph | Benefit | |-------------------|----------------|---------| | grep -r "auth" | codegraph_search("auth") | Instant symbol lookup | | Multiple Read calls | codegraph_context(task) | Related code in one call | | Manual file tracing | codegraph_callers/callees | Call graph traversal | | Guessing impact | codegraph_impact(symbol) | Know what breaks |

This hybrid approach gives you ~30% fewer tokens and ~25% fewer tool calls while letting Claude's native agents handle synthesis.

📚 Library Usage

CodeGraph can also be used as a library in your Node.js applications:

import CodeGraph from '@mduenas/codegraph';

// Initialize a new project
const cg = await CodeGraph.init('/path/to/project');

// Or open an existing one
const cg = await CodeGraph.open('/path/to/project');

// Index with progress callback
await cg.indexAll({
  onProgress: (progress) => {
    console.log(`${progress.phase}: ${progress.current}/${progress.total}`);
  }
});

// Search for symbols
const results = cg.searchNodes('UserService');

// Get callers of a function
const node = results[0].node;
const callers = cg.getCallers(node.id);

// Build context for a task
const context = await cg.buildContext('fix login bug', {
  maxNodes: 20,
  includeCode: true,
  format: 'markdown'
});

// Get impact radius
const impact = cg.getImpactRadius(node.id, 2);

// Sync changes
const syncResult = await cg.sync();

// Clean up
cg.close();

⚙️ How It Works

1. Extraction

CodeGraph uses tree-sitter to parse source code into ASTs. Language-specific queries (.scm files) extract:

• Nodes: Functions, methods, classes, interfaces, types, variables
• Edges: Calls, imports, extends, implements, returns_type

Each node gets a unique ID based on its kind, file path, name, and line number.

2. Storage

All data is stored in a local SQLite database (.codegraph/codegraph.db):

• nodes table: All code entities with metadata
• edges table: Relationships between nodes
• files table: File tracking for incremental updates
• node_vectors / vector_map: Embeddings for semantic search (using sqlite-vss)

3. Reference Resolution

After extraction, CodeGraph resolves references:

1. Match function calls to function definitions
2. Resolve imports to their source files
3. Link class inheritance and interface implementations
4. Apply framework-specific patterns (Express routes, etc.)

4. Semantic Search

CodeGraph uses local embeddings (via @xenova/transformers) to enable semantic search:

1. Code symbols are embedded using a transformer model
2. Queries are embedded and compared using cosine similarity
3. Results are ranked by relevance

5. Graph Queries

The graph structure enables powerful queries:

• Callers/Callees: Direct call relationships
• Impact Radius: BFS traversal to find all potentially affected code
• Dependencies: What a symbol depends on
• Dependents: What depends on a symbol

6. Context Building

When you request context for a task:

1. Semantic search finds relevant entry points
2. Graph traversal expands to related code
3. Code snippets are extracted
4. Results are formatted for AI consumption

⚙️ Configuration

The .codegraph/config.json file controls indexing behavior:

{
  "version": 1,
  "projectName": "my-project",
  "languages": ["typescript", "javascript"],
  "exclude": [
    "node_modules/**",
    "dist/**",
    "build/**",
    "*.min.js"
  ],
  "frameworks": ["express", "react"],
  "maxFileSize": 1048576,
  "gitHooksEnabled": true
}

Options

| Option | Description | Default | |--------|-------------|---------| | languages | Languages to index (auto-detected if empty) | [] | | exclude | Glob patterns to ignore | ["node_modules/**", ...] | | frameworks | Framework hints for better resolution | [] | | maxFileSize | Skip files larger than this (bytes) | 1048576 (1MB) | | gitHooksEnabled | Enable git hook installation | true |

🌐 Supported Languages

| Language | Extension | Status | |----------|-----------|--------| | TypeScript | .ts, .tsx | Full support | | JavaScript | .js, .jsx, .mjs | Full support | | Python | .py | Full support | | Go | .go | Full support | | Rust | .rs | Full support | | Java | .java | Full support | | C# | .cs | Full support | | PHP | .php | Full support | | Ruby | .rb | Full support | | C | .c, .h | Full support | | C++ | .cpp, .hpp, .cc | Full support | | Swift | .swift | Full support | | Kotlin | .kt, .kts | Full support |

🔧 Troubleshooting

"CodeGraph not initialized"

Run codegraph init in your project directory first.

Indexing is slow

• Check if node_modules or other large directories are excluded
• Use --quiet flag to reduce console output overhead
• Consider increasing maxFileSize if you have large files to skip

MCP server not connecting

1. Ensure the project is initialized and indexed
2. Check the path in your MCP configuration is correct
3. Verify codegraph serve --mcp works from the command line
4. Check Claude Code logs for connection errors

Missing symbols in search

• Run codegraph sync to pick up recent changes
• Check if the file's language is supported
• Verify the file isn't excluded by config patterns

📄 License

MIT

Made for the Claude Code community 🤖

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