codebase-research

codebase-research is a skill for Claude Code from mhylle/claude-skills-collection. It costs 72 tokens per session (1,770 once invoked), scanned A, original, MIT.

A workflow for documenting how an existing codebase works. It searches for relevant files, maps components and connections, and explains the current implementation without changing it.

In plain words
What is it for?
Use it to find where a feature lives, explain how components interact, or produce documentation of the repository as it currently exists.
Why use it?
It makes unfamiliar code easier to understand without mixing research with redesign or improvement suggestions.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: mentions subagents; names the TodoWrite tool.

Part of the devflow plugin — 38 skills, 13 agents, 5 hooks shipped together

Good fit Use it to find where a feature lives, explain how components interact, or produce documentation of the repository as it currently exists.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/mhylle/claude-skills-collection/codebase-research
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.

Any agent
npx skills add mhylle/claude-skills-collection --skill codebase-research
Clone the repo
git clone --depth 1 https://github.com/mhylle/claude-skills-collection

Made for: Claude Code.

Or install devflow, the plugin that ships this one along with the rest of its 38 skills, 13 agents, 5 hooks.

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-research

README.md
[![agentmods](https://agentmods.dev/badge/skills/mhylle/claude-skills-collection/codebase-research/github.svg)](https://agentmods.dev/skills/mhylle/claude-skills-collection/codebase-research)
Your own site
<a href="https://agentmods.dev/skills/mhylle/claude-skills-collection/codebase-research"><img src="https://agentmods.dev/badge/skills/mhylle/claude-skills-collection/codebase-research/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-research

Your own site · 80×15
<a href="https://agentmods.dev/skills/mhylle/claude-skills-collection/codebase-research"><img src="https://agentmods.dev/badge/skills/mhylle/claude-skills-collection/codebase-research.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 72 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,770 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. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 5.1 $0.00072 $0.01770
Opus 5 $0.00036 $0.00885
Sonnet 5 $0.00014 $0.00354
Haiku 4.5 $0.00007 $0.00177

Measured 9d ago against content hash 199dd6bb490d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

codebase-research 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 9d 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.

skills/codebase-research/SKILL.md · 249 lines

How it starts

The opening of the file, as written. The whole thing — 249 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Codebase Research

Overview

This skill enables comprehensive codebase research through parallel sub-agent orchestration. It decomposes research questions into focused sub-tasks, executes them in parallel for efficiency, and synthesizes findings into structured research documents.

Critical Constraint

THE ONLY JOB IS TO DOCUMENT AND EXPLAIN THE CODEBASE AS IT EXISTS TODAY.

Do NOT:

  • Suggest improvements unless explicitly requested
  • Perform uninvited root cause analysis
  • Propose enhancements or optimizations
  • Critique implementation choices or identify problems
  • Recommend refactoring or architectural changes

DO:

  • Describe what exists
  • Explain where functionality lives
  • Document how components work
  • Map component interactions and dependencies

Initial Response

When this skill is invoked, respond:

"I'm ready to research the codebase. Please provide your research question or area of interest, and I'll analyze it thoroughly by exploring relevant components and connections."

Available Sub-Agents

Codebase Agents

Agent Purpose When to Use
codebase-locator Finds files by topic/feature Need to locate all files related to a feature
codebase-analyzer Traces implementation with file:line refs Need to understand how code works
codebase-pattern-finder Finds code patterns with examples Need to see how patterns are implemented

Documentation Agents

Agent Purpose When to Use
docs-locator Finds docs, ADRs, design documents Need to find documentation about a topic
docs-analyzer Extracts decisions and specs from docs Need to understand documented decisions

External Research

Agent Purpose When to Use
web-search-researcher Researches external documentation Explicitly requested or need external context

Research Workflow

Step 1: Read Mentioned Files

Read the full file on GitHub · 249 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. 9d ago First seen · 249 lines · 72 tokens per session scan A 199dd6bb490d

Subscribe to this mod's changes

codebase-research is a skill published in the GitHub repository mhylle/claude-skills-collection (18 stars, last pushed 6d ago), licensed MIT. It adds 72 tokens to every session and 1,770 once invoked, about $0.0004 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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