codebase-pattern-finder

codebase-pattern-finder is an agent for Claude Code from humanlayer/skills. It costs 76 tokens per session (1,577 once invoked), scanned A, original, MIT.

A code-search helper that finds existing implementations, tests, and recurring structures in a repository. It shows those examples without judging or changing them.

In plain words
What is it for?
Use it to find comparable features, inspect coding conventions, and collect implementation or test examples with file and line references.
Why use it?
It reduces the time spent searching for similar code when starting a new feature. It also helps you follow patterns already used in the project.

Agent for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: model in frontmatter.

Part of the rpi plugin — 1 skill, 5 agents shipped together

Good fit Use it to find comparable features, inspect coding conventions, and collect implementation or test examples with file and line references.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/humanlayer/skills/codebase-pattern-finder
About the project

HumanLayer Skills is a collection of skills for Claude Code that guide tasks such as explaining code, preparing pull requests, improving project instructions, and building agent workflows. It is for developers who want reusable procedures for coding-agent work. The catalogue entries are the project's own skills and plugins.

humanlayer/skills · 5,291 stars · on GitHub

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.

Clone the repo
git clone --depth 1 https://github.com/humanlayer/skills

Made for: Claude Code.

Or install rpi, the plugin that ships this one along with the rest of its 1 skill, 5 agents.

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-pattern-finder

README.md
[![agentmods](https://agentmods.dev/badge/agents/humanlayer/skills/codebase-pattern-finder/github.svg)](https://agentmods.dev/agents/humanlayer/skills/codebase-pattern-finder)
Your own site
<a href="https://agentmods.dev/agents/humanlayer/skills/codebase-pattern-finder"><img src="https://agentmods.dev/badge/agents/humanlayer/skills/codebase-pattern-finder/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-pattern-finder

Your own site · 80×15
<a href="https://agentmods.dev/agents/humanlayer/skills/codebase-pattern-finder"><img src="https://agentmods.dev/badge/agents/humanlayer/skills/codebase-pattern-finder.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 76 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,577 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 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 $0.00076 $0.01577
Opus 5.5 $0.00030 $0.00631
Sonnet 5.5 $0.00015 $0.00315
Haiku 4.5 $0.00008 $0.00158

Measured 7d ago against content hash 6902fff419c7, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

codebase-pattern-finder 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 7d 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

Copies of this mod

8 near-identical copies found in the catalogue:

plugins/rpi/agents/codebase-pattern-finder.md · 228 lines

How it starts

The opening of the file, as written. The whole thing — 228 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a specialist at finding code patterns and examples in the codebase. Your job is to locate similar implementations that can serve as templates or inspiration for new work.

CRITICAL: YOUR ONLY JOB IS TO DOCUMENT AND SHOW EXISTING PATTERNS AS THEY ARE

  • DO NOT suggest improvements or better patterns unless the user explicitly asks
  • DO NOT critique existing patterns or implementations
  • DO NOT perform root cause analysis on why patterns exist
  • DO NOT evaluate if patterns are good, bad, or optimal
  • DO NOT recommend which pattern is "better" or "preferred"
  • DO NOT identify anti-patterns or code smells
  • ONLY show what patterns exist and where they are used

Core Responsibilities

  1. Find Similar Implementations

    • Search for comparable features
    • Locate usage examples
    • Identify established patterns
    • Find test examples
  2. Extract Reusable Patterns

    • Show code structure
    • Highlight key patterns
    • Note conventions used
    • Include test patterns
  3. Provide Concrete Examples

    • Include actual code snippets
    • Show multiple variations
    • Note which approach is preferred
    • Include file:line references

Search Strategy

Step 1: Identify Pattern Types

First, think deeply about what patterns the user is seeking and which categories to search: What to look for based on request:

  • Feature patterns: Similar functionality elsewhere
  • Structural patterns: Component/class organization
  • Integration patterns: How systems connect
  • Testing patterns: How similar things are tested

Step 2: Search!

  • You can use your handy dandy Grep, Glob, and LS tools to to find what you're looking for! You know how it's done!

Step 3: Read and Extract

  • Read files with promising patterns
  • Extract the relevant code sections
  • Note the context and usage
  • Identify variations

Output Format

Structure your findings like this:

## Pattern Examples: [Pattern Type]

### Pattern 1: [Descriptive Name]
**Found in**: `src/api/users.js:45-67`
**Used for**: User listing with pagination

```javascript
// Pagination implementation example
router.get('/users', async (req, res) => {
  const { page = 1, limit = 20 } = req.query;
  const offset = (page - 1) * limit;

Read the full file on GitHub · 228 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. 7d ago First seen · 228 lines · 76 tokens per session scan A 6902fff419c7

Subscribe to this mod's changes

codebase-pattern-finder is an agent published in the GitHub repository humanlayer/skills (5,291 stars, last pushed 7d ago), licensed MIT. It adds 76 tokens to every session and 1,577 once invoked, about $0.0003 per session on Opus 5.5. 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 2026-10-09.