codebase-navigator

When searching for code, tracing a bug, or understanding how modules connect. Use before grepping blindly — consult the index first.

Skill for Claude CodeCodex

Part of the agentskel plugin — 52 skills, 2 hooks shipped together

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/ahmadulhoq/agentskel/codebase-navigator
Any agent
npx skills add ahmadulhoq/agentskel --skill codebase-navigator
Clone the repo
git clone --depth 1 https://github.com/ahmadulhoq/agentskel

Made for: Claude Code, Codex.

Or install agentskel, the plugin that ships this one along with the rest of its 52 skills, 2 hooks.

Per session 31 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 477 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 $0.00031 $0.00477
Opus 5 $0.00015 $0.00238
Sonnet 5 $0.00006 $0.00095
Haiku 4.5 $0.00003 $0.00048

Measured yesterday against content hash 437a096b0b09, 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.

.agents/skills/codebase-navigator/SKILL.md · 50 lines

What it actually says

Codebase Navigator

Purpose: Use the project's indexed knowledge (MAP.md, SYMBOLS.md) to find code efficiently. The cartographer has already mapped the codebase — use the map.


What the index contains

File What it tells you When to use it
MAP.md Module registry — every module, its responsibility, key entry points, critical flows Which module owns this? How do modules connect? What's the end-to-end flow?
SYMBOLS.md Symbol index — every class and named function with file paths Where is this class/function defined? What functions does this class have?
symbols/*.md Per-module symbol files (split mode only) Full symbol table for a specific module

How to use them

Finding where something lives

  1. Check SYMBOLS.md — if it's an index (split mode), find the module row
  2. Read symbols/[module].md for the full symbol table of that module
  3. If symbols/ doesn't exist (single-file mode), SYMBOLS.md has everything directly

Understanding module ownership

  1. Check MAP.md for the module that owns the responsibility
  2. Read the module's key entry points to orient yourself

Tracing a flow

  1. Check MAP.md Critical Business Logic Flows for documented flows
  2. Follow the entry points listed there

Finding callers and implementation details

Grep is the right tool for this — the index tells you where things are defined, not who calls them. Once you've located the file via SYMBOLS.md, grep for callers.

When to skip the index

  • You already have the exact file path (e.g. from a TECH_DEBT entry or error stack trace)
  • You're searching for a string literal, log message, or error code (not a symbol)
  • The index is stale (check the timestamp at the top of each file)

No gate. This is an advisory skill, not a mandatory procedure.

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 · 50 lines · 31 tokens per session scan A 437a096b0b09

Subscribe to this mod's changes

codebase-navigator is a skill published in the GitHub repository ahmadulhoq/agentskel (13 stars, last pushed 17d ago), licensed MIT. It adds 31 tokens to every session and 477 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 2026-09-02.

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