PentestGPT: Skill for Claude Code

.agents/skills/codebase-design/SKILL.md

codebase-design is a skill for Claude Code, Codex from GreyDGL/PentestGPT. It costs 57 tokens per session (1,351 once invoked), scanned A, a copy of codebase-design, MIT.

A set of design terms and principles for planning code modules: self-contained pieces of code with a small interface and substantial behaviour behind it.

In plain words
What is it for?
It helps design or improve modules, identify clean seams in a codebase, make code more testable, and make structures easier for both developers and coding agents to navigate.
Why use it?
It provides shared language for deciding where code should be split, how interfaces should work, and how to make modules easier to test and maintain.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions subagents; installed under .agents/ (shared by several agents).

This is GreyDGL/PentestGPT's own configuration. It tells Claude Code and Codex how to work on PentestGPT itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything PentestGPT configures →

About the project

PentestGPT is an AI-driven framework for penetration testing and capture-the-flag challenges. It guides staged workflows such as reconnaissance, asset discovery, vulnerability identification, exploitation, and reporting, using large language models to operate tools and reason about findings. The catalogue includes skills and instructions for using it.

GreyDGL/PentestGPT · 16,045 stars · on GitHub

Reuse

Borrowing it

Nothing to install: this file belongs to GreyDGL/PentestGPT. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/GreyDGL/PentestGPT/main/.agents/skills/codebase-design/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/GreyDGL/PentestGPT

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for codebase-design

README.md
[![agentmods](https://agentmods.dev/badge/skills/greydgl/pentestgpt/codebase-design/github.svg)](https://agentmods.dev/skills/greydgl/pentestgpt/codebase-design)
Your own site
<a href="https://agentmods.dev/skills/greydgl/pentestgpt/codebase-design"><img src="https://agentmods.dev/badge/skills/greydgl/pentestgpt/codebase-design/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for codebase-design

Your own site · 80×15
<a href="https://agentmods.dev/skills/greydgl/pentestgpt/codebase-design"><img src="https://agentmods.dev/badge/skills/greydgl/pentestgpt/codebase-design.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 57 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,351 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin 100% copy Near-identical to another mod 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 5.1 $0.00057 $0.01351
Opus 5.5 $0.00023 $0.00540
Sonnet 5.5 $0.00011 $0.00270
Haiku 4.5 $0.00006 $0.00135

Measured 1mo ago against content hash a8d50abac5a4, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

codebase-design 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 1mo 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.

Origin

This is a copy

100% identical to codebase-design — 26 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.agents/skills/codebase-design/SKILL.md · 115 lines

How it starts

The opening of the file, as written. The whole thing — 115 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Codebase Design

Design deep modules: a lot of behaviour behind a small interface, placed at a clean seam, testable through that interface. Use this language and these principles wherever code is being designed or restructured. The aim is leverage for callers, locality for maintainers, and testability for everyone.

Glossary

Use these terms exactly — don't substitute "component," "service," "API," or "boundary." Consistent language is the whole point.

Module — anything with an interface and an implementation. Deliberately scale-agnostic: a function, class, package, or tier-spanning slice. Avoid: unit, component, service.

Interface — everything a caller must know to use the module correctly: the type signature, but also invariants, ordering constraints, error modes, required configuration, and performance characteristics. Avoid: API, signature (too narrow — they refer only to the type-level surface).

Implementation — what's inside a module, its body of code. Distinct from Adapter: a thing can be a small adapter with a large implementation (a Postgres repo) or a large adapter with a small implementation (an in-memory fake). Reach for "adapter" when the seam is the topic; "implementation" otherwise.

Depth — leverage at the interface: the amount of behaviour a caller (or test) can exercise per unit of interface they have to learn. A module is deep when a large amount of behaviour sits behind a small interface, shallow when the interface is nearly as complex as the implementation.

Seam (Michael Feathers) — a place where you can alter behaviour without editing in that place; the location at which a module's interface lives. Where to put the seam is its own design decision, distinct from what goes behind it. Avoid: boundary (overloaded with DDD's bounded context).

Adapter — a concrete thing that satisfies an interface at a seam. Describes role (what slot it fills), not substance (what's inside).

Leverage — what callers get from depth: more capability per unit of interface they learn. One implementation pays back across N call sites and M tests.

Read the full file on GitHub · 115 lines

Files

What ships with it

2 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. 1mo ago First seen · 115 lines · 57 tokens per session scan A a8d50abac5a4

Subscribe to this mod's changes

codebase-design is a skill published in the GitHub repository GreyDGL/PentestGPT (16,045 stars, last pushed 3mo ago), licensed MIT. It adds 57 tokens to every session and 1,351 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 100% identical to codebase-design, differing in 26 lines, and is treated as a copy.

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