A tool for finding duplicated or structurally similar C# code in .NET repositories.

Use it to scan a solution, project, or source folder for repeated C# code and to track duplication findings over time.

Copy-pasted code makes fixes harder to keep consistent and can hide repeated logic. Duplicate-code reports help identify candidates for refactoring.

quickdup — Skill for Claude Code and Codex by managedcode

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 managedcode/dotnet-skills --skill quickdup

Clone the repo

git clone --depth 1 https://github.com/managedcode/dotnet-skills

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/managedcode/dotnet-skills/quickdup/github.svg)](https://agentmods.dev/skills/managedcode/dotnet-skills/quickdup)

Your own site

<a href="https://agentmods.dev/skills/managedcode/dotnet-skills/quickdup"><img src="https://agentmods.dev/badge/skills/managedcode/dotnet-skills/quickdup/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/managedcode/dotnet-skills/quickdup"><img src="https://agentmods.dev/badge/skills/managedcode/dotnet-skills/quickdup.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 138 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,417 The whole file, excluding the scripts and references it only reads on demand.

Security scan C 2 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.

Model	Per session	Once invoked
Fable 5.1	$0.00138	$0.01417
Opus 5	$0.00069	$0.00709
Sonnet 5	$0.00028	$0.00283
Haiku 4.5	$0.00014	$0.00142

Measured 5d ago against content hash bdc464e7db11, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade C, and why

quickdup scanned grade C with 2 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 5d 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.

Downloads and executes remote codehighSupply chain

curl | sh runs whatever the server returns today, which is not necessarily what it returned when this was reviewed.

- official macOS/Linux fallback: `curl -sSL https://raw.githubusercontent.com/asynkron/Asynkron.QuickDup/main/install.sh | bash`

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

- official macOS/Linux fallback: `curl -sSL https://raw.githubusercontent.com/asynkron/Asynkron.QuickDup/main/install.sh | bash`

Origin

Copies of this mod

3 near-identical copies found in the catalogue:

dotnet-quickdup — 97% identical, 12 lines differ
mcaf-dotnet-quickdup — 95% identical, 10 lines differ
mcaf-dotnet-quickdup — 95% identical, 10 lines differ

catalog/Tools/QuickDup/skills/quickdup/SKILL.md · 134 lines

How it starts

The opening of the file, as written. The whole thing — 134 lines — stays where its author put it; the contents beside it link to each section on GitHub.

QuickDup for .NET

Trigger On

the repo wants QuickDup
the team needs repeatable duplicate-code scans for C#
the user asks about DRY cleanup, copy-paste detection, clone detection, or duplicate logic removal in a .NET repo

Value

produce a concrete project delta: code, docs, config, tests, CI, or review artifact
reduce ambiguity through explicit planning, verification, and final validation skills
leave reusable project context so future tasks are faster and safer

Do Not Use For

formatting-only work
repos that intentionally use a different clone detector and do not want overlap
generated-code churn where duplication findings would mostly be noise

Inputs

the nearest AGENTS.md
target solution, project, or source subtree
current duplication hotspots and generated-code boundaries

Quick Start

Read the nearest AGENTS.md and confirm scope and constraints.
Run this skill's Workflow through the Ralph Loop until outcomes are acceptable.
Return the Required Result Format with concrete artifacts and verification evidence.

Workflow

Choose the scan target deliberately:
- whole solution for broad discovery
- bounded folders for targeted cleanup
Scan C# with .cs only unless the repo explicitly wants Razor, generated XML, or other extensions too.
Exclude generated and transient paths before trusting the results:
- bin/
- obj/
- Migrations/ when scaffold churn dominates
- *.g.cs
- *.generated.cs
- *.Designer.cs
Review the top patterns before refactoring anything.
Classify duplication before changing code:
- real structural duplication worth extraction
- domain-shape duplication that documents intent
- generated or acceptable duplication that should be ignored
Prefer small extractions, named helpers, shared value objects, or focused abstractions over flag-heavy merge methods.
Re-run QuickDup after the refactor and then run the repo's normal quality pass.

Read the full file on GitHub · 134 lines

Files

What ships with it

4 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.

5d ago First seen · 134 lines · 138 tokens per session scan C bdc464e7db11

Subscribe to this mod's changes

quickdup is a skill published in the GitHub repository managedcode/dotnet-skills (477 stars, last pushed 3d ago), licensed MIT. It adds 138 tokens to every session and 1,417 once invoked, about $0.0007 per session on Opus 5. A static security scan graded it C with 2 findings (downloads and executes remote code, makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

C# and .NET Claude Code Code review Languages codex copilot dotnet dotnet-skills skills

winui-setup

Install and verify the prerequisites the win-dev-skills WinUI 3 toolchain depends on — .NET SDK 8.0.100+, WinApp CLI 0.6+, and Developer Mode. Use only when the user explicitly asks to set up or repair the toolchain. Do not invoke automatically when another skill reports a missing prerequisite; tell the user what is…

microsoft/win-dev-skills · 88 tokens

winui-wpf-migration

Migrate WPF applications to WinUI 3 — namespace replacement (System.Windows → Microsoft.UI.Xaml), control mapping (DataGrid→ListView, WrapPanel→ItemsRepeater, TabControl→TabView), threading (Dispatcher→DispatcherQueue), imaging (System.Drawing→BitmapImage), MVVM conversion to CommunityToolkit.Mvvm, and…

microsoft/win-dev-skills · 100 tokens

opengis-skills

Use when AI coding assistant needs GIS/CAD/C#/AI/IoT/3D domain expertise for 73+ open-source projects. One-stop skill index with tag-based search and on-demand loading for GDAL, GeoServer, QGIS, PostGIS, JTS, CesiumJS, FreeCAD, OpenSCAD, OCCT, NPOI, SqlSugar, Furion, Dify, SuperSplat, Go and more.

znlgis/opengis-skills · 97 tokens

quickdup