codebase-overview

A skill that gives a quick overview of an unfamiliar codebase, including its structure, technologies, and likely architecture. A codebase is the collection of source code and related project files.

In plain words
What is it for?
Use it when joining a project, learning how the code is organized, identifying its technology stack, or getting an initial view of its architecture and code-quality signals.
Why use it?
It reduces the time needed to orient yourself in a new repository and helps you identify where to look next.

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/lis186/sourceatlas/codebase-overview
Any agent
npx skills add lis186/SourceAtlas --skill codebase-overview
Clone the repo
git clone --depth 1 https://github.com/lis186/SourceAtlas

Made for: Claude Code, Codex.

Per session 57 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 261 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 $0.00057 $0.00261
Opus 5 $0.00028 $0.00130
Sonnet 5 $0.00011 $0.00052
Haiku 4.5 $0.00006 $0.00026

Measured 2d ago against content hash 843136dfe317, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

codebase-overview 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.

plugin/skills/codebase-overview/SKILL.md · 37 lines

What it actually says

Codebase Overview

When to Use

Trigger this skill when the user:

  • Asks about project structure or architecture
  • Is new to a codebase and needs orientation
  • Wants to understand tech stack or patterns used
  • Asks "what is this project about"
  • Asks "how is this organized"

Instructions

  1. Run /sourceatlas:overview to analyze the codebase
  2. This scans <5% of high-entropy files (configs, READMEs, models)
  3. Returns project fingerprint, architecture hypotheses, and AI collaboration level

What User Gets

  • Project type and scale
  • Tech stack identification
  • Architecture patterns with confidence levels
  • Code quality signals
  • Recommended next steps

Example Triggers

  • "I just joined this project, where do I start?"
  • "What's the architecture of this codebase?"
  • "Give me an overview of this project"
  • "What tech stack does this use?"
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 · 37 lines · 57 tokens per session scan A 843136dfe317

Subscribe to this mod's changes

codebase-overview is a skill published in the GitHub repository lis186/SourceAtlas (46 stars, last pushed 1mo ago), licensed MIT. It adds 57 tokens to every session and 261 once invoked, about $0.0003 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.

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