code-navigation

A codebase-navigation guide describing tools and routines for finding files, symbols, references, and relevant sections of code.

In plain words
What is it for?
Use it to explore a codebase, search for patterns, inspect function or type definitions, trace references, and read only targeted line ranges.
Why use it?
It reduces the time and context needed to understand a large repository and helps avoid reading unrelated files.

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/markerikson/opencode-config-example/code-navigation
Any agent
npx skills add markerikson/opencode-config-example --skill code-navigation
Clone the repo
git clone --depth 1 https://github.com/markerikson/opencode-config-example

Made for: Claude Code, Codex.

Per session 0 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,064 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 $0.00000 $0.01064
Opus 5 $0.00000 $0.00532
Sonnet 5 $0.00000 $0.00213
Haiku 4.5 $0.00000 $0.00106

Measured 2d ago against content hash 5d21bff64e60, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

code-navigation 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 2d ago.

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.

config/skill/code-navigation/SKILL.md · 82 lines

How it starts

The opening of the file, as written. The whole thing — 82 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Code Navigation & File Reading

Full tool reference for navigating codebases. The AGENTS.md quick-reference table covers tool selection; this skill provides detailed usage patterns, workflows, and edge cases.

Grepika — Default Exploration Tool

Use grepika first for all code exploration and reading.

Commands

  • grepika_toc — directory tree overview
  • grepika_search — find code patterns (regex or natural language). Requires index — run grepika_index first if results are empty/stale.
  • grepika_outline — extract file structure (functions, classes, types). Always do this before reading code.
  • grepika_get with start_line/end_line — read targeted sections. Use outline results to pick exact line ranges. Never omit line range on large files.
  • grepika_context — see surrounding code at a search match location
  • grepika_refs — find all references to a symbol/identifier
  • grepika_index — rebuild search index if results seem stale. Use force=true for full rebuild.

Core Workflow

grepika_outline → identify symbols of interest → grepika_get with line range → read only what's needed

Repeat as necessary. This keeps context lean.

Tilth — Structural / Definition Queries

When you need to know where something is defined or what calls what, prefer tilth over grepika.

Commands

  • tilth_read — smart file reading. Small files shown whole, large files auto-outlined with drillable line ranges.
  • tilth_search — definition-first search. Finds where symbols are defined (not just string matches), shows surrounding structure, resolves callees inline.
    • Use scope param to limit to a subdirectory
    • Multi-symbol: pass comma-separated names to trace across files in one call
    • Callers: kind: callers finds all call sites using tree-sitter structural matching
  • tilth_deps — blast-radius check. Shows what a file imports and what other files use its exports. Use before breaking changes (renaming exports, changing signatures).

Read the full file on GitHub · 82 lines

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. 2d ago First seen · 82 lines · 0 tokens per session scan A 5d21bff64e60

Subscribe to this mod's changes

code-navigation is a skill published in the GitHub repository markerikson/opencode-config-example (44 stars, last pushed 3mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 1,064 tokens. 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 2026-08-30.

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