Agent skill

Finding Duplicate Functions

A skill your agent uses when auditing a codebase for semantic duplication - functions that do the same thing but have different names or implementations.

MITAuto-check passed

Install Finding Duplicate Functions

skills CLI

$ npx skills add obra/superpowers-lab --skill finding-duplicate-functions -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install obra/superpowers-lab finding-duplicate-functions --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/obra/superpowers-lab.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/finding-duplicate-functions .claude/skills/finding-duplicate-functions && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Paste into Claude Code

Install the "finding-duplicate-functions" agent skill from https://github.com/obra/superpowers-lab/tree/main/skills/finding-duplicate-functions into .claude/skills/finding-duplicate-functions/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "finding-duplicate-functions", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/obra/superpowers-lab/tree/main/skills/finding-duplicate-functions

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add obra/superpowers-lab --skill finding-duplicate-functions -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install obra/superpowers-lab finding-duplicate-functions --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/obra/superpowers-lab.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/finding-duplicate-functions .agents/skills/finding-duplicate-functions && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "finding-duplicate-functions" agent skill from https://github.com/obra/superpowers-lab/tree/main/skills/finding-duplicate-functions into .agents/skills/finding-duplicate-functions/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "finding-duplicate-functions", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add obra/superpowers-lab --skill finding-duplicate-functions -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install obra/superpowers-lab finding-duplicate-functions --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/obra/superpowers-lab.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/finding-duplicate-functions .cursor/skills/finding-duplicate-functions && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "finding-duplicate-functions" agent skill from https://github.com/obra/superpowers-lab/tree/main/skills/finding-duplicate-functions into .cursor/skills/finding-duplicate-functions/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "finding-duplicate-functions", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/obra/superpowers-lab.git --path skills/finding-duplicate-functions

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add obra/superpowers-lab --skill finding-duplicate-functions -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install obra/superpowers-lab finding-duplicate-functions --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/obra/superpowers-lab.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/finding-duplicate-functions .gemini/skills/finding-duplicate-functions && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "finding-duplicate-functions" agent skill from https://github.com/obra/superpowers-lab/tree/main/skills/finding-duplicate-functions into .gemini/skills/finding-duplicate-functions/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "finding-duplicate-functions", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install obra/superpowers-lab finding-duplicate-functions

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add obra/superpowers-lab --skill finding-duplicate-functions -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/obra/superpowers-lab.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/finding-duplicate-functions .github/skills/finding-duplicate-functions && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "finding-duplicate-functions" agent skill from https://github.com/obra/superpowers-lab/tree/main/skills/finding-duplicate-functions into .github/skills/finding-duplicate-functions/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "finding-duplicate-functions", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add obra/superpowers-lab --skill finding-duplicate-functions -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install obra/superpowers-lab finding-duplicate-functions --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/obra/superpowers-lab.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/finding-duplicate-functions .opencode/skills/finding-duplicate-functions && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "finding-duplicate-functions" agent skill from https://github.com/obra/superpowers-lab/tree/main/skills/finding-duplicate-functions into .opencode/skills/finding-duplicate-functions/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "finding-duplicate-functions", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: finding-duplicate-functions
GitHub stars: 429
Used in: 2 other repos
Token cost: ~1.2k tokens
SKILL.md length: 427 words
Files: 6 (incl. scripts)
Skills in repo: 2
Repo updated: Jun 1, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

A skill your agent uses when auditing a codebase for semantic duplication - functions that do the same thing but have different names or implementations.

Works in 6 steps: Extract Function Catalog → Categorize by Domain → Split into Categories → …
Auditing a codebase for semantic duplication - functions that do the same thing but have different names
SKILL.md covers Overview, When to Use, Quick Reference and Process, plus 2 more sections
Runs Shell scripts from its folder

What it does

Finding Duplicate Functions is an agent skill from obra/superpowers-lab. Use when auditing a codebase for semantic duplication - functions that do the same thing but have different names or implementations. Especially useful for LLM-generated codebases where new functions are often created rather than reusing existing ones.

Its SKILL.md is about 1.2k tokens, which your agent loads only when the skill is triggered. The skill folder holds 6 other files, including scripts (for example `scripts/categorize-prompt.md`, `scripts/extract-functions.sh` and `scripts/find-duplicates-prompt.md`).

The repository describes itself as: Experimental skills for Claude Code Superpowers - new techniques and tools. The licence is MIT.

When your agent uses it

Auditing a codebase for semantic duplication - functions that do the same thing but have different names
Implementations

Example prompts

“/finding-duplicate-functions”

Requirements

A Bash shell

Workflow steps

6 steps, taken from the step headings in SKILL.md.

Extract Function Catalog
Categorize by Domain
Split into Categories
Find Duplicates (Per Category)
Generate Report
Human Review

What it can do on your machine

Read from SKILL.md and the folder at commit 51111f7. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Ships 5 files in scripts/ (Shell), which the agent can run.
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Finding Duplicate Functions loads about 1.2k tokens when it runs. Until then it costs about 70 tokens; SKILL.md has 427 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~70
When it runs · the whole SKILL.md, loaded when a task matches: ~1.2k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); the scripts in this folder are not scanned.

SKILL.md

The full file from obra/superpowers-lab at commit 51111f7, republished under its MIT licence (© obra). 427 words, ~1,199 tokens.

Download SKILL.mdSave it as .claude/skills/finding-duplicate-functions/SKILL.md (or your agent's skills folder). This skill also uses 5 other files; get the full folder from GitHub.

name: finding-duplicate-functions
description: Use when auditing a codebase for semantic duplication - functions that do the same thing but have different names or implementations. Especially useful for LLM-generated codebases where new functions are often created rather than reusing existing ones.

Finding Duplicate-Intent Functions

Overview

LLM-generated codebases accumulate semantic duplicates: functions that serve the same purpose but were implemented independently. Classical copy-paste detectors (jscpd) find syntactic duplicates but miss "same intent, different implementation."

This skill uses a two-phase approach: classical extraction followed by LLM-powered intent clustering.

When to Use

Codebase has grown organically with multiple contributors (human or LLM)
You suspect utility functions have been reimplemented multiple times
Before major refactoring to identify consolidation opportunities
After jscpd has been run and syntactic duplicates are already handled

Quick Reference

Phase	Tool	Model	Output
1. Extract	`scripts/extract-functions.sh`	-	`catalog.json`
2. Categorize	`scripts/categorize-prompt.md`	haiku	`categorized.json`
3. Split	`scripts/prepare-category-analysis.sh`	-	`categories/*.json`
4. Detect	`scripts/find-duplicates-prompt.md`	opus	`duplicates/*.json`
5. Report	`scripts/generate-report.sh`	-	`report.md`

Process

dot

digraph duplicate_detection {
  rankdir=TB;
  node [shape=box];

  extract [label="1. Extract function catalog\n./scripts/extract-functions.sh"];
  categorize [label="2. Categorize by domain\n(haiku subagent)"];
  split [label="3. Split into categories\n./scripts/prepare-category-analysis.sh"];
  detect [label="4. Find duplicates per category\n(opus subagent per category)"];
  report [label="5. Generate report\n./scripts/generate-report.sh"];
  review [label="6. Human review & consolidate"];

  extract -> categorize -> split -> detect -> report -> review;
}

Phase 1: Extract Function Catalog

bash

./scripts/extract-functions.sh src/ -o catalog.json

Options:

-o FILE: Output file (default: stdout)
-c N: Lines of context to capture (default: 15)
-t GLOB: File types (default: *.ts,*.tsx,*.js,*.jsx)
--include-tests: Include test files (excluded by default)

Test files (*.test.*, *.spec.*, __tests__/**) are excluded by default since test utilities are less likely to be consolidation candidates.

Phase 2: Categorize by Domain

Dispatch a haiku subagent using the prompt in scripts/categorize-prompt.md.

Insert the contents of catalog.json where indicated in the prompt template. Save output as categorized.json.

Phase 3: Split into Categories

bash

./scripts/prepare-category-analysis.sh categorized.json ./categories

Creates one JSON file per category. Only categories with 3+ functions are worth analyzing.

Phase 4: Find Duplicates (Per Category)

For each category file in ./categories/, dispatch an opus subagent using the prompt in scripts/find-duplicates-prompt.md.

Save each output as ./duplicates/{category}.json.

Phase 5: Generate Report

bash

./scripts/generate-report.sh ./duplicates ./duplicates-report.md

Produces a prioritized markdown report grouped by confidence level.

Show full SKILL.md (173 more words)Show less

Phase 6: Human Review

Review the report. For HIGH confidence duplicates:

Verify the recommended survivor has tests
Update callers to use the survivor
Delete the duplicates
Run tests

High-Risk Duplicate Zones

Focus extraction on these areas first - they accumulate duplicates fastest:

Zone	Common Duplicates
`utils/`, `helpers/`, `lib/`	General utilities reimplemented
Validation code	Same checks written multiple ways
Error formatting	Error-to-string conversions
Path manipulation	Joining, resolving, normalizing paths
String formatting	Case conversion, truncation, escaping
Date formatting	Same formats implemented repeatedly
API response shaping	Similar transformations for different endpoints

Common Mistakes

Extracting too much: Focus on exported functions and public methods. Internal helpers are less likely to be duplicated across files.

Skipping the categorization step: Going straight to duplicate detection on the full catalog produces noise. Categories focus the comparison.

Using haiku for duplicate detection: Haiku is cost-effective for categorization but misses subtle semantic duplicates. Use Opus for the actual duplicate analysis.

Consolidating without tests: Before deleting duplicates, ensure the survivor has tests covering all use cases of the deleted functions.

Files

SKILL.md and 5 other files (scripts) in skills/finding-duplicate-functions of obra/superpowers-lab.

SKILL.md
scripts/categorize-prompt.md
scripts/extract-functions.sh
scripts/find-duplicates-prompt.md
scripts/generate-report.sh
scripts/prepare-category-analysis.sh

Open the folder on GitHubat commit 51111f7

Used in 2 other repositories

We found 2 copies of this SKILL.md (exact, near-identical or edited) in other folders, from 2 other GitHub owners. This page covers the copy in obra/superpowers-lab, which our catalogue first saw on October 7, 2026.

Compare with similar skills

Finding Duplicate Functions next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Finding Duplicate Functions compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
Finding Duplicate Functions this skillobra/superpowers-lab	429	2 repos	~1.2k	Automated safety check: Pass	MIT	4 mo ago
Find Similar Functionsmillionco/react-doctor	15k	—	~1.2k	Automated safety check: Pass	Custom licence	today
Finding Duplicate Functionsbobmatnyc/claude-mpm	155	—	~1.3k	Automated safety check: Pass	MIT	1 mo ago
Production Auditaffaan-m/ECC	274k	1 repos	~1.9k	Automated safety check: Pass	MIT	2 days ago
Aims Auditalirezarezvani/claude-skills	28k	—	~1.3k	Automated safety check: Pass	MIT	1 mo ago
Click Path Auditaffaan-m/ECC	274k	3 repos	~2k	Automated safety check: Pass	MIT	2 days ago

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Auto-check passed

Questions about Finding Duplicate Functions

What does Finding Duplicate Functions do?

A skill your agent uses when auditing a codebase for semantic duplication - functions that do the same thing but have different names or implementations. Finding Duplicate Functions is an agent skill from obra/superpowers-lab. Use when auditing a codebase for semantic duplication - functions that do the same thing but have different names or implementations.

When should I use Finding Duplicate Functions?

Finding Duplicate Functions fits situations like: auditing a codebase for semantic duplication - functions that do the same thing but have different names; implementations.

How do I install Finding Duplicate Functions in Claude Code?

Run `npx skills add obra/superpowers-lab --skill finding-duplicate-functions -a claude-code`. Or copy the skill folder (skills/finding-duplicate-functions in obra/superpowers-lab) into .claude/skills/finding-duplicate-functions in your project. Claude Code loads it when a task matches its description.

How do I install Finding Duplicate Functions in Codex?

Run `npx skills add obra/superpowers-lab --skill finding-duplicate-functions -a codex`. Or copy the skill folder (skills/finding-duplicate-functions in obra/superpowers-lab) into .agents/skills/finding-duplicate-functions in your project. Codex loads it when a task matches its description.

Can I use Finding Duplicate Functions in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add obra/superpowers-lab --skill finding-duplicate-functions -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/finding-duplicate-functions, .gemini/skills/finding-duplicate-functions, .github/skills/finding-duplicate-functions and .opencode/skills/finding-duplicate-functions in your project.

What does Finding Duplicate Functions need to run?

Going by SKILL.md and its folder, Finding Duplicate Functions needs a shell for the scripts in its folder. Our summary lists: A Bash shell.

Does Finding Duplicate Functions access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Finding Duplicate Functions safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. The check reads SKILL.md only: the scripts in the folder are not scanned, so read them before running anything.

What licence does Finding Duplicate Functions use?

Finding Duplicate Functions is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Finding Duplicate Functions use?

About 1.2k tokens (SKILL.md is roughly 4.8k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Finding Duplicate Functions?

Skills that share tags, products or a category with Finding Duplicate Functions: Find Similar Functions (millionco/react-doctor, 15k stars), Finding Duplicate Functions (bobmatnyc/claude-mpm, 155 stars), Production Audit (affaan-m/ECC, 274k stars) and Aims Audit (alirezarezvani/claude-skills, 28k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Finding Duplicate Functions?

obra (a GitHub user) maintains it in obra/superpowers-lab, which has 429 GitHub stars. The repository holds 2 skills in this directory. The repository was last updated on June 1, 2026.

Source: obra/superpowers-lab on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Install Finding Duplicate Functions

Facts

At a glance

What it does

When your agent uses it

Example prompts

Requirements

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

Finding Duplicate-Intent Functions

Overview

When to Use

Quick Reference

Process

Phase 1: Extract Function Catalog

Phase 2: Categorize by Domain

Phase 3: Split into Categories

Phase 4: Find Duplicates (Per Category)

Phase 5: Generate Report

Phase 6: Human Review

High-Risk Duplicate Zones

Common Mistakes

Files

Used in 2 other repositories

Compare with similar skills

Similar skills

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