codebase-navigator

A codebase analysis toolkit that maps how a software project is organised and how its parts connect. It can find starting points, important modules, repeated patterns, and the path data takes through the code.

In plain words
What is it for?
For scanning a project, listing its languages and entry points, mapping imports and dependencies, finding circular dependencies, and tracing a function or symbol.
Why use it?
It reduces the time spent opening files at random when joining an unfamiliar project or looking for where a feature is implemented.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/jansenanalytics/claudex/codebase-navigator
Any agent
npx skills add JansenAnalytics/claudex --skill codebase-navigator
Clone the repo
git clone --depth 1 https://github.com/JansenAnalytics/claudex

Made for: Claude Code, Codex.

Per session 30 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 483 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00030 $0.00483
Opus 5 $0.00015 $0.00242
Sonnet 5 $0.00006 $0.00097
Haiku 4.5 $0.00003 $0.00048

Measured yesterday against content hash a51cc63a9577, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

codebase-navigator scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/codebase-navigator/SKILL.md · 76 lines

What it actually says

codebase-navigator

Rapidly understand any codebase: identify entry points, map architecture, find key patterns, summarize modules, trace data flow.

When to Use

  • Onboarding to a new project
  • Understanding unfamiliar code
  • Finding where functionality lives
  • Mapping dependencies between modules
  • Creating architectural overviews

Scripts

codebase-scan.sh

Quick codebase overview — detects languages, frameworks, entry points, file counts.

bash scripts/codebase-scan.sh /path/to/project
bash scripts/codebase-scan.sh .

Output: Markdown summary with languages, frameworks, entry points, directory structure, LOC counts.

module-map.py

Build a module/import dependency map.

python3 scripts/module-map.py --dir src/
python3 scripts/module-map.py --dir src/ --format mermaid
python3 scripts/module-map.py --dir lib/ --format json

Arguments:

  • --dir <path> — Directory to scan (default: .)
  • --format tree|mermaid|json — Output format (default: tree)

Identifies: core modules (most imported), leaf modules, circular dependencies.

trace-flow.sh

Trace a function/symbol through the codebase.

bash scripts/trace-flow.sh --symbol "handlePayment" --dir src/
bash scripts/trace-flow.sh --symbol "UserService" --depth 3

Arguments:

  • --symbol <name> — Function/class/string to trace (required)
  • --dir <path> — Directory to search (default: .)
  • --depth <n> — Call chain depth (default: 2)

Uses rg (ripgrep) for fast searching.

References

  • codebase-patterns.md — Common project structures and how to identify them

Requirements

  • rg (ripgrep) — For fast code searching
  • python3 — For module-map.py
Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 76 lines · 30 tokens per session scan A a51cc63a9577

Subscribe to this mod's changes

codebase-navigator is a skill published in the GitHub repository JansenAnalytics/claudex (5 stars, last pushed 2mo ago), licensed MIT. It adds 30 tokens to every session and 483 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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