codeindex

Repo dependency analyzer with blast-radius impact scoring and symbol indexing for AI-assisted development.

Point it at any project — Python, JavaScript/TypeScript, Go, Ruby, Rust, Java, PHP, and more — and get:

• A codeindex.json dependency index written directly into your repo
• Per-file blast-radius scores (how many files break if this one changes)
• A symbolindex.json symbol map so AI can find any function/class without scanning every file
• Five ways to consume the data: CLI, markdown report, MCP server, pre-commit hook, CLAUDE.md injection
• An interactive visualization UI (2D/3D graphs, dependency matrix, treemap)

No build step. No npm. Pure Python stdlib — zero required dependencies.

Install

pip install codeindex

Or from source:

git clone https://github.com/scheidydude/codeindex
cd codeindex
pip install -e .

Quickstart

# Build the dependency index
codeindex analyze ./myapp

# Build the symbol index (where every function and class lives)
codeindex symbols ./myapp

# See blast radius for a file before touching it
codeindex impact src/auth.py

# Launch the visualization UI
codeindex serve --viz --repo ./myapp
open http://localhost:8080

Commands

codeindex analyze

codeindex analyze [REPO_PATH] [--output PATH] [--watch]

Analyzes the repo and writes codeindex.json to the repo root. Detects 12+ languages automatically.

codeindex symbols

codeindex symbols [REPO_PATH] [--output PATH] [--inline] [--index PATH]
                  [--claude-md] [--claude-md-path PATH] [--all-symbols]

Builds a symbol index — a map of every function, class, struct, and type to its exact file and line number. Lets AI tools (and humans) find any symbol in one lookup instead of scanning the entire repo.

Modes:

Both --inline and --claude-md can be combined in a single run.

Options:

Examples:

# Standalone symbol index
codeindex symbols ./myapp

# Embed into codeindex.json (one file for blast radius + symbols)
codeindex symbols ./myapp --inline

# Write CLAUDE.md summary so Claude Code loads symbols automatically
codeindex symbols ./myapp --claude-md

# All three at once
codeindex symbols ./myapp --inline --claude-md

# Re-generate when code changes
codeindex symbols ./myapp --inline --claude-md

Why it matters: Claude Code and other AI tools normally scan every file to find a function definition. With a symbol index, Claude can load one file, do an O(1) lookup, and open only the relevant file — cutting token usage 60–90% on symbol-location tasks.

CLAUDE.md injection is opt-in because it increases base context size on every prompt. Use it when symbol lookups are frequent in your workflow; skip it for simple tasks where the overhead outweighs the benefit.

codeindex impact

codeindex impact FILE [--index PATH] [--out FILE] [--json]

Shows the blast-radius impact for a specific file: direct dependents, transitive dependents, blast score, and risk level.

Impact: src/auth.py
Blast Score: 8.5  (2 direct · 7 transitive)  [HIGH]

Direct dependents (2)
  src/api.py
  src/middleware.py

Transitive dependents (5 additional)
  src/main.py  ← src/api.py
  src/app.py   ← src/middleware.py
  ...

Risk: HIGH — affects 7/42 files (16.7% of codebase)

Blast score formula: direct + (0.5 × transitive)

codeindex serve

codeindex serve --viz [--repo PATH] [--port PORT] [--watch]
codeindex serve --mcp

--viz launches an interactive visualization UI in your browser (5 modes: 2D force graph, 3D network, dependency matrix, treemap, infrastructure graph).

--mcp starts a stdio MCP server that exposes codeindex tools directly to Claude and other MCP clients.

MCP tools:

Claude Code MCP config (.claude/settings.json):

{
  "mcpServers": {
    "codeindex": {
      "command": "codeindex",
      "args": ["serve", "--mcp"]
    }
  }
}

codeindex lookup

codeindex lookup SYMBOL [--index PATH] [--json]

Finds where a function, class, struct, or other symbol is defined. O(1) lookup against symbolindex.json — no file scanning.

$ codeindex lookup compute_blast_radius
codeindex/impact.py:6  (function)

$ codeindex lookup AuthService
src/auth.py:44  (class)  methods: login, logout, refresh

codeindex dependencies

codeindex dependencies FILE [--index PATH] [--json]

Shows what a file imports and what imports it, plus its blast score.

$ codeindex dependencies src/auth.py
File: src/auth.py  (blast score: 8.5)

Imports (3):
  src/db.py
  src/config.py
  src/utils.py

Imported by (2):
  src/api.py
  src/middleware.py

codeindex high-blast

codeindex high-blast [--threshold N] [--index PATH] [--json]

Lists all files whose blast score exceeds the threshold, sorted by score descending. Useful for identifying the riskiest files before a refactor.

$ codeindex high-blast --threshold 5
Files with blast score ≥ 5.0  (3 found)

  13.0  src/db.py          (12d / 2t)
   8.5  src/auth.py        (3d / 7t)
   5.5  src/config.py      (5d / 1t)

d = direct dependents · t = transitive dependents

codeindex install-hook

codeindex install-hook [--repo PATH] [--threshold N] [--strict] [--remove]

Installs a git pre-commit hook that warns when staged files exceed the blast score threshold.

Using codeindex in another repo with Claude

Three workflows, ordered by automation level.

Workflow 1 — MCP server (recommended for active coding)

Claude gets symbol lookup, dependency, and impact tools it calls automatically. No extra prompting needed.

One-time setup:

cd /your/other/repo
codeindex analyze .
codeindex symbols .

Register the MCP server with Claude Code using claude mcp add. Use --scope project to limit it to this repo, or --scope global to use it everywhere:

# Project-scoped (recommended — stored in .claude/settings.json)
claude mcp add --scope project codeindex -- /path/to/codeindex serve --mcp

# Global (available in all repos)
claude mcp add --scope global codeindex -- /path/to/codeindex serve --mcp

Find the full path to your codeindex binary with which codeindex, then substitute it above.

# Example with conda install
claude mcp add --scope project codeindex -- /opt/homebrew/Caskroom/miniforge/base/bin/codeindex serve --mcp

Verify it registered:

claude mcp list

Note: Do not use "command": "codeindex" with a bare name — Claude Code does not inherit your shell PATH, so the binary won't be found unless you use the absolute path.

Claude now has all 6 MCP tools available in every session. When it needs to find processPayment, it calls lookup_symbol("processPayment") and gets src/billing.py:142 back in one shot — no file scanning.

Keep the index fresh:

# Auto-rebuild on file changes (leave running in a terminal)
codeindex symbols . --watch

Workflow 2 — CLAUDE.md injection (best for repos you revisit often)

Symbol table is embedded in CLAUDE.md so it loads into every session automatically — no tool call needed at all.

cd /your/other/repo
codeindex symbols . --claude-md

This upserts a symbolindex code fence into CLAUDE.md. Every Claude Code session in that repo loads it at startup. Claude can answer "where is X defined?" from context alone with zero tool calls.

Tradeoff: adds ~500–2000 tokens to every prompt depending on repo size. Worth it for repos where symbol lookups are frequent; skip it for repos where you mostly write new code.

Keep it fresh:

# Re-run after significant refactors
codeindex analyze . && codeindex symbols . --claude-md

Workflow 3 — Hybrid (large repos)

For large repos where the --claude-md section would be too large, use the MCP server for lookups and add a short hint to CLAUDE.md so Claude reaches for the tool first:

codeindex analyze .
codeindex symbols .

Then add to CLAUDE.md:

## Codeindex
Symbol index: `symbolindex.json` — use the `lookup_symbol` MCP tool before grepping for any function or class.
Dependency index: `codeindex.json` — use `get_impact` before modifying high-blast files.

This costs almost no tokens but primes Claude to use the index rather than defaulting to grep.

CLI quick reference for human use

The same data available via MCP is also accessible directly from the terminal:

# Find where a symbol is defined
codeindex lookup MyClassName
codeindex lookup process_payment --json

# Show what a file imports and what depends on it
codeindex dependencies src/auth.py

# List the riskiest files to change
codeindex high-blast --threshold 5

# Blast-radius report before touching a file
codeindex impact src/auth.py

Which workflow to pick

Supported Languages

Output schemas

codeindex.json

{
  "meta": {
    "root": "myapp/",
    "total_files": 60,
    "total_loc": 4085,
    "languages": ["python", "javascript"]
  },
  "nodes": [
    {
      "id": "src/auth.py",
      "type": "module",
      "language": "python",
      "layer": "backend",
      "loc": 142,
      "imports": ["src/db.py"],
      "imported_by": ["src/api.py", "src/middleware.py"],
      "direct_dependents": 2,
      "transitive_dependents": 7,
      "blast_score": 5.5,
      "symbols": [
        { "name": "verify_token", "line": 18, "kind": "function", "exported": true },
        { "name": "AuthService",  "line": 44, "kind": "class",    "exported": true,
          "methods": ["login", "logout", "refresh"] }
      ]
    }
  ],
  "links": [
    { "source": "src/api.py", "target": "src/auth.py", "weight": 1, "kind": "imports" }
  ]
}

The symbols field is only present when codeindex symbols --inline has been run.

symbolindex.json

{
  "meta": {
    "generated": "2026-05-21",
    "repo": "myapp/",
    "total_symbols": 312
  },
  "symbols": {
    "verify_token": [
      {
        "file": "src/auth.py",
        "line": 18,
        "kind": "function",
        "exported": true,
        "doc": "Verify a JWT and return the decoded payload."
      }
    ],
    "AuthService": [
      {
        "file": "src/auth.py",
        "line": 44,
        "kind": "class",
        "exported": true,
        "methods": ["login", "logout", "refresh"]
      }
    ]
  },
  "file_symbols": {
    "src/auth.py": [
      { "name": "verify_token", "line": 18, "kind": "function", "exported": true },
      { "name": "AuthService",  "line": 44, "kind": "class",    "exported": true,
        "methods": ["login", "logout", "refresh"] }
    ]
  }
}

Lookup patterns:

• "Where is verify_token defined?" → symbols["verify_token"][0].file + .line — O(1)
• "What symbols live in src/auth.py?" → file_symbols["src/auth.py"] — O(1)
• "What's the blast radius of changing verify_token?" → cross-reference codeindex.json via the file

CLAUDE.md symbol section

When --claude-md is used, a compact section is upserted into CLAUDE.md bounded by HTML comment markers so re-runs update in place:

<!-- codeindex-symbols-start -->
## Symbol Index
_Generated by codeindex. Update: `codeindex symbols --claude-md`_

```symbolindex
src/auth.py: verify_token:fn:18 AuthService:cls:44[login,logout,refresh]
src/db.py: connect:fn:12 query:fn:28 close:fn:55

Format per symbol: `name:kind_abbr:line[methods...]`
Kind abbreviations: `fn` function · `cls` class · `st` struct · `en` enum · `tr` trait · `if` interface · `ty` type · `co` const

---

## AI workflow comparison

| Task | Without codeindex | With symbolindex.json |
|------|-------------------|----------------------|
| Find where `process_payment` is defined | Grep / scan ~200 files | Load 1 file, O(1) lookup |
| Understand blast radius of a change | Manual tracing | `codeindex impact <file>` |
| Load only relevant context | Full repo scan | File + line from symbol map |
| Estimated token savings | baseline | **60–90% on symbol tasks** |

---

## Optional dependencies

| Package | Purpose | Install |
|---------|---------|---------|
| `watchdog` | `--watch` file change detection | `pip install 'codeindex[watch]'` |
| `PyYAML` | Better Docker Compose / CI YAML parsing | `pip install 'codeindex[yaml]'` |
| `tomli` | Rust `Cargo.toml` on Python < 3.11 | `pip install 'codeindex[toml]'` |

---

## Requirements

- Python 3.9+
- A modern browser (for `--viz` mode)

---

## License

Apache 2.0 — free to use and build on; attribution required in derivative works and documentation. Copyright 2026 David Scheiderman.