exploration

An evidence-based workflow for exploring an unfamiliar codebase, meaning a software project whose structure and design are not yet known. It maps files, entry points, dependencies, and common architecture patterns.

In plain words
What is it for?
It is for identifying the technology stack, main startup files, important directories, package dependencies, and patterns such as MVC, Clean Architecture, or a Next.js App Router project.
Why use it?
It gives the agent a repeatable way to understand a project before making changes, reducing guesses about how the code is organized.

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/fusengine/agents/exploration
Any agent
npx skills add fusengine/agents --skill exploration
Clone the repo
git clone --depth 1 https://github.com/fusengine/agents

Made for: Claude Code, Codex.

Per session 23 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 808 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 $0.00023 $0.00808
Opus 5 $0.00012 $0.00404
Sonnet 5 $0.00005 $0.00162
Haiku 4.5 $0.00002 $0.00081

Measured yesterday against content hash b5325e5f8ef5, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

exploration 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.

plugins/ai-pilot/skills/exploration/SKILL.md · 77 lines

How it starts

The opening of the file, as written. The whole thing — 77 lines — stays where its author put it; the contents beside it link to each section on GitHub.

It is evidence-based only -- no assumptions without code proof -- and produces a structured report of tech stack, entry points, and detected architecture pattern for whoever consumes it (typically the APEX Analyze phase or a domain expert).

Session: ${CLAUDE_SESSION_ID}

Exploration Skill

Exploration Protocol

Run these 5 phases in order — full commands in references/exploration-protocol.md:

  1. Initial Reconnaissance — list root files, find config files, check common entry points
  2. Structure Mapping — tree view (excluding noise dirs), identify main directories
  3. Entry Points Detection — grep for main/index/server bootstrap per language
  4. Dependency Analysis — read package.json/pyproject.toml/go.mod/Cargo.toml/composer.json
  5. Pattern Detection — check for MVC, Clean/Hexagonal, feature-based, Next.js App Router directories

Architecture Pattern Detection

Pattern Indicators

Pattern Key Directories Indicators
MVC controllers/, models/, views/ Rails, Laravel, Express
Clean Architecture domain/, application/, infrastructure/ DDD, Use cases
Hexagonal adapters/, ports/, core/ Ports & adapters
Feature-based features/[name]/ All layers per feature
Layered presentation/, business/, data/ Traditional 3-tier
Monolith Single src/ Mixed concerns
Microservices Multiple services/ Separate repos/folders
Next.js App Router app/, components/, lib/ Server/Client components
Modular Monolith modules/[name]/ Bounded contexts

Read the full file on GitHub · 77 lines

Files

What ships with it

5 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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 · 77 lines · 23 tokens per session scan A b5325e5f8ef5

Subscribe to this mod's changes

exploration is a skill published in the GitHub repository fusengine/agents (25 stars, last pushed 28d ago), licensed MIT. It adds 23 tokens to every session and 808 once invoked, about $0.0001 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 2026-08-30.