Axon

Graph-powered code intelligence engine — indexes your codebase into a knowledge graph and exposes it via MCP tools for AI agents and a CLI for developers.

axon analyze .

Phase 1:  Walking files...               142 files found
Phase 3:  Parsing code...                142/142
Phase 5:  Tracing calls...               847 calls resolved
Phase 7:  Analyzing types...             234 type relationships
Phase 8:  Detecting communities...       8 clusters found
Phase 9:  Detecting execution flows...   34 processes found
Phase 10: Finding dead code...           12 unreachable symbols
Phase 11: Analyzing git history...       18 coupled file pairs

Done in 4.2s — 623 symbols, 1,847 edges, 8 clusters, 34 flows

Most code intelligence tools treat your codebase as flat text. Axon builds a structural graph — every function, class, import, call, type reference, and execution flow becomes a node or edge in a queryable knowledge graph. AI agents using Axon don't just search for keywords; they understand how your code is connected.

Why Axon?

For AI agents (Claude Code, Cursor):

• "What breaks if I change this function?" → blast radius via call graph + type references + git coupling
• "What code is never called?" → dead code detection with framework-aware exemptions
• "Show me the login flow end-to-end" → execution flow tracing from entry points through the call graph
• "Which files always change together?" → git history change coupling analysis

For developers:

• Instant answers to architectural questions without grepping through files
• Find dead code, tightly coupled files, and execution flows automatically
• Raw Cypher queries against your codebase's knowledge graph
• Watch mode that re-indexes on every save

Zero cloud dependencies. Everything runs locally — parsing, graph storage, embeddings, search. No API keys, no data leaving your machine.

Features

11-Phase Analysis Pipeline

Axon doesn't just parse your code — it builds a deep structural understanding through 11 sequential analysis phases:

Hybrid Search (BM25 + Vector + RRF)

Three search strategies fused with Reciprocal Rank Fusion:

• BM25 full-text search — fast exact name and keyword matching via KuzuDB FTS
• Semantic vector search — conceptual queries via 384-dim embeddings (BAAI/bge-small-en-v1.5)
• Fuzzy name search — Levenshtein fallback for typos and partial matches

Test files are automatically down-ranked (0.5x), source-level functions/classes boosted (1.2x).

Dead Code Detection

Finds unreachable symbols with intelligence — not just "zero callers" but a multi-pass analysis:

1. Initial scan — flags functions/methods/classes with no incoming calls
2. Exemptions — entry points, exports, constructors, test code, dunder methods, __init__.py public symbols, decorated functions, @property methods
3. Override pass — un-flags methods that override non-dead base class methods (handles dynamic dispatch)
4. Protocol conformance — un-flags methods on classes conforming to Protocol interfaces
5. Protocol stubs — un-flags all methods on Protocol classes (interface contracts)

Impact Analysis (Blast Radius)

When you're about to change a symbol, Axon traces upstream through:

• Call graph — every function that calls this one, recursively
• Type references — every function that takes, returns, or stores this type
• Git coupling — files that historically change alongside this one

Community Detection

Uses the Leiden algorithm (igraph + leidenalg) to automatically discover functional clusters in your codebase. Each community gets a cohesion score and auto-generated label based on member file paths.

Execution Flow Tracing

Detects entry points using framework-aware patterns:

• Python: @app.route, @router.get, @click.command, test_* functions, __main__ blocks
• JavaScript/TypeScript: Express handlers, exported functions, handler/middleware patterns

Then traces BFS execution flows from each entry point through the call graph, classifying flows as intra-community or cross-community.

Change Coupling (Git History)

Analyzes 6 months of git history to find hidden dependencies that static analysis misses:

coupling(A, B) = co_changes(A, B) / max(changes(A), changes(B))

Files with coupling strength ≥ 0.3 and 3+ co-changes get linked. Surfaces coupled files in impact analysis.

Watch Mode

Live re-indexing powered by a Rust-based file watcher (watchfiles):

$ axon watch
Watching /Users/you/project for changes...

[10:32:15] src/auth/validate.py modified → re-indexed (0.3s)
[10:33:02] 2 files modified → re-indexed (0.5s)

• File-local phases (parse, imports, calls, types) run immediately on change
• Global phases (communities, processes, dead code) batch every 30 seconds

Branch Comparison

Structural diff between branches using git worktrees (no stashing required):

$ axon diff main..feature

Symbols added (4):
  + process_payment (Function) -- src/payments/stripe.py
  + PaymentIntent (Class) -- src/payments/models.py

Symbols modified (2):
  ~ checkout_handler (Function) -- src/routes/checkout.py

Symbols removed (1):
  - old_charge (Function) -- src/payments/legacy.py

Supported Languages

Installation

# With pip
pip install axoniq

# With uv (recommended)
uv add axoniq

# With Neo4j backend support
pip install axoniq[neo4j]

Requires Python 3.11+.

From Source

git clone https://github.com/harshkedia177/axon.git
cd axon
uv sync --all-extras
uv run axon --help

Quick Start

1. Index Your Codebase

cd your-project
axon analyze .

2. Query It

# Search for symbols
axon query "authentication handler"

# Get full context on a symbol
axon context validate_user

# Check blast radius before changing something
axon impact UserModel --depth 3

# Find dead code
axon dead-code

# Run a raw Cypher query
axon cypher "MATCH (n:Function) WHERE n.is_dead = true RETURN n.name, n.file_path"

3. Keep It Updated

# Watch mode — re-indexes on every save
axon watch

# Or re-analyze manually
axon analyze .

CLI Reference

axon analyze [PATH]          Index a repository (default: current directory)
    --full                   Force full rebuild (skip incremental)

axon status                  Show index status for current repo
axon list                    List all indexed repositories
axon clean                   Delete index for current repo
    --force / -f             Skip confirmation prompt

axon query QUERY             Hybrid search the knowledge graph
    --limit / -n N           Max results (default: 20)

axon context SYMBOL          360-degree view of a symbol
axon impact SYMBOL           Blast radius analysis
    --depth / -d N           BFS traversal depth (default: 3)

axon dead-code               List all detected dead code
axon cypher QUERY            Execute a raw Cypher query (read-only)

axon watch                   Watch mode — live re-indexing on file changes
axon diff BASE..HEAD         Structural branch comparison

axon setup                   Print MCP configuration JSON
    --claude                 For Claude Code
    --cursor                 For Cursor

axon mcp                     Start the MCP server (stdio transport)
axon serve                   Start the MCP server (same as axon mcp)
    --watch, -w              Enable live file watching with auto-reindex
axon --version               Print version

MCP Integration

Axon exposes its full intelligence as an MCP server, giving AI agents like Claude Code and Cursor deep structural understanding of your codebase.

Setup for Claude Code

Add to your .claude/settings.json or project .mcp.json:

{
  "mcpServers": {
    "axon": {
      "command": "axon",
      "args": ["serve", "--watch"]
    }
  }
}

This starts the MCP server with live file watching — the knowledge graph updates automatically as you edit code. To run without watching, use "args": ["mcp"] instead.

Or run the setup helper:

axon setup --claude

Setup for Cursor

Add to your Cursor MCP settings:

{
  "axon": {
    "command": "axon",
    "args": ["serve", "--watch"]
  }
}

Or run:

axon setup --cursor

MCP Tools

Once connected, your AI agent gets access to these tools:

Every tool response includes a next-step hint guiding the agent through a natural investigation workflow:

query → "Next: Use context() on a specific symbol for the full picture."
context → "Next: Use impact() if planning changes to this symbol."
impact → "Tip: Review each affected symbol before making changes."

MCP Resources

Knowledge Graph Model

Nodes

Relationships

Node ID Format

{label}:{relative_path}:{symbol_name}

Examples:
  function:src/auth/validate.py:validate_user
  class:src/models/user.py:User
  method:src/models/user.py:User.save

Architecture

Source Code (.py, .ts, .js, .tsx, .jsx)
    │
    ▼
┌──────────────────────────────────────────────┐
│         Ingestion Pipeline (11 phases)        │
│                                               │
│  walk → structure → parse → imports → calls   │
│  → heritage → types → communities → processes │
│  → dead_code → coupling                       │
└──────────────────────┬───────────────────────┘
                       │
                       ▼
              ┌─────────────────┐
              │ KnowledgeGraph  │  (in-memory during build)
              └────────┬────────┘
                       │
          ┌────────────┼────────────┐
          ▼            ▼            ▼
     ┌─────────┐ ┌─────────┐ ┌─────────┐
     │ KuzuDB  │ │  FTS    │ │ Vector  │
     │ (graph) │ │ (BM25)  │ │ (HNSW)  │
     └────┬────┘ └────┬────┘ └────┬────┘
          └────────────┼────────────┘
                       │
              StorageBackend Protocol
                       │
              ┌────────┴────────┐
              ▼                 ▼
        ┌──────────┐     ┌──────────┐
        │   MCP    │     │   CLI    │
        │  Server  │     │ (Typer)  │
        │ (stdio)  │     │          │
        └────┬─────┘     └────┬─────┘
             │                │
        Claude Code      Terminal
        / Cursor         (developer)

Tech Stack

Storage

Everything lives locally in your repo:

your-project/
└── .axon/
    ├── kuzu/          # KuzuDB graph database (graph + FTS + vectors)
    └── meta.json      # Index metadata and stats

Add .axon/ to your .gitignore.

The storage layer is abstracted behind a StorageBackend Protocol — KuzuDB is the default, with an optional Neo4j backend available via pip install axoniq[neo4j].

Example Workflows

"I need to refactor the User class — what breaks?"

# See everything connected to User
axon context User

# Check blast radius
axon impact User --depth 3

# Find which files always change with user.py
axon cypher "MATCH (a:File)-[r:CodeRelation]->(b:File) WHERE a.name = 'user.py' AND r.rel_type = 'coupled_with' RETURN b.name, r.strength ORDER BY r.strength DESC"

"Is there dead code we should clean up?"

axon dead-code

"What are the main execution flows in our app?"

axon cypher "MATCH (p:Process) RETURN p.name, p.properties ORDER BY p.name"

"Which parts of the codebase are most tightly coupled?"

axon cypher "MATCH (a:File)-[r:CodeRelation]->(b:File) WHERE r.rel_type = 'coupled_with' RETURN a.name, b.name, r.strength ORDER BY r.strength DESC LIMIT 20"

How It Compares

Development

git clone https://github.com/harshkedia177/axon.git
cd axon
uv sync --all-extras

# Run tests
uv run pytest

# Lint
uv run ruff check src/

# Run from source
uv run axon --help

License

MIT

Built by @harshkedia177