Agent skill

Simplify

Wrap-up refactoring — simplify code, eliminate duplication, preserve behavior

MITAuto-check passedDevelopment

Install Simplify

skills CLI

$ npx skills add sd0xdev/sd0x-harness --skill simplify -a claude-code

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

GitHub CLI

$ gh skill install sd0xdev/sd0x-harness simplify --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/sd0xdev/sd0x-harness.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/simplify .claude/skills/simplify && 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 "simplify" agent skill from https://github.com/sd0xdev/sd0x-harness/tree/main/skills/simplify into .claude/skills/simplify/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "simplify", 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/sd0xdev/sd0x-harness/tree/main/skills/simplify

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 sd0xdev/sd0x-harness --skill simplify -a codex

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

GitHub CLI

$ gh skill install sd0xdev/sd0x-harness simplify --agent codex

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

Manual copy

$ git clone --depth 1 https://github.com/sd0xdev/sd0x-harness.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/simplify .agents/skills/simplify && 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 "simplify" agent skill from https://github.com/sd0xdev/sd0x-harness/tree/main/skills/simplify into .agents/skills/simplify/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "simplify", 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 sd0xdev/sd0x-harness --skill simplify -a cursor

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

GitHub CLI

$ gh skill install sd0xdev/sd0x-harness simplify --agent cursor

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

Manual copy

$ git clone --depth 1 https://github.com/sd0xdev/sd0x-harness.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/simplify .cursor/skills/simplify && 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 "simplify" agent skill from https://github.com/sd0xdev/sd0x-harness/tree/main/skills/simplify into .cursor/skills/simplify/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "simplify", 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/sd0xdev/sd0x-harness.git --path skills/simplify

--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 sd0xdev/sd0x-harness --skill simplify -a gemini-cli

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

GitHub CLI

$ gh skill install sd0xdev/sd0x-harness simplify --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/sd0xdev/sd0x-harness.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/simplify .gemini/skills/simplify && 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 "simplify" agent skill from https://github.com/sd0xdev/sd0x-harness/tree/main/skills/simplify into .gemini/skills/simplify/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "simplify", 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 sd0xdev/sd0x-harness simplify

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 sd0xdev/sd0x-harness --skill simplify -a github-copilot

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

Manual copy

$ git clone --depth 1 https://github.com/sd0xdev/sd0x-harness.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/simplify .github/skills/simplify && 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 "simplify" agent skill from https://github.com/sd0xdev/sd0x-harness/tree/main/skills/simplify into .github/skills/simplify/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "simplify", 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 sd0xdev/sd0x-harness --skill simplify -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 sd0xdev/sd0x-harness simplify --agent opencode

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

Manual copy

$ git clone --depth 1 https://github.com/sd0xdev/sd0x-harness.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/simplify .opencode/skills/simplify && 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 "simplify" agent skill from https://github.com/sd0xdev/sd0x-harness/tree/main/skills/simplify into .opencode/skills/simplify/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "simplify", 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: simplify
GitHub stars: 192
Token cost: ~388 tokens
SKILL.md length: 85 words
Files: 1
Skills in repo: 91
Repo updated: Oct 6, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

Wrap-up refactoring — simplify code, eliminate duplication, preserve behavior

Works in 3 steps: Run tests first (establish baseline) → Refactor → Run tests again (confirm nothing broken)
Tasks that involve Code simplification
SKILL.md covers Trigger, When NOT to Use, Agent Dispatch and Task, plus 2 more sections
Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Simplify is an agent skill from sd0xdev/sd0x-harness. Wrap-up refactoring — simplify code, eliminate duplication, preserve behavior

Its SKILL.md is about 390 tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

It sits in Development, covering Code simplification and Refactoring. The repository describes itself as: The harness layer for Claude Code — a reference implementation of harness engineering with hook-enforced dual review, state-machine gates that survive context compaction, and… The licence is MIT.

When your agent uses it

Tasks that involve Code simplification
Tasks that involve Refactoring

Example prompts

“/simplify”

Requirements

Node.js
Pre-approved tools (allowed-tools): Read, Grep, Glob, Edit, Bash(TEST_ENV=unit npx jest:*), Agent

Workflow steps

3 steps, taken from the first numbered list in SKILL.md.

Run tests first (establish baseline)
Refactor
Run tests again (confirm nothing broken)

What it can do on your machine

Read from SKILL.md and the folder at commit c9a2036. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves these tools, so the agent can use them without asking each time:
- Read
- Grep
- Glob
- Edit
- Bash(TEST_ENV=unit npx jest:*)
- Agent
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md (its code samples are markdown).
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

Simplify loads about 388 tokens when it runs. Until then it costs about 22 tokens; SKILL.md has 85 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~22
When it runs · the whole SKILL.md, loaded when a task matches: ~388

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); files beside SKILL.md are not scanned.

SKILL.md

The full file from sd0xdev/sd0x-harness at commit c9a2036, republished under its MIT licence (© sd0xdev). 85 words, ~388 tokens.

Download SKILL.mdSave it as .claude/skills/simplify/SKILL.md (or your agent's skills folder).

name: simplify
description: Wrap-up refactoring — simplify code, eliminate duplication, preserve behavior
allowed-tools: Read, Grep, Glob, Edit, Bash(TEST_ENV=unit npx jest:*), Agent

Code Simplification

Trigger

Keywords: simplify, clean up code, remove duplication, simplify code

When NOT to Use

New feature development (use /feature-dev)
Document refactoring (use /doc-refactor)
Full multi-target refactoring (use /refactor)

Agent Dispatch

Primary: Code Simplification

Agent({
  description: "Simplify code, eliminate duplication, preserve behavior",
  subagent_type: "code-simplifier",
  prompt: `Simplify the code at: $ARGUMENTS
Follow the task steps and constraints defined in this skill.`
})

Secondary: Refactoring Risk Review

After simplification, dispatch risk assessment:

Agent({
  description: "Review refactoring risk and verify behavior preservation",
  subagent_type: "refactor-reviewer",
  prompt: `Review the refactoring changes just applied.
Check behavior preservation, dependency impact, test coverage, and rollback risk.`
})

Task

For $ARGUMENTS:

Run tests first (establish baseline)
Refactor
- Dead code removal
- Extract duplicates (3+ repeats)
- Simplify nesting (> 3 levels)
Run tests again (confirm nothing broken)

Output

markdown

## Refactoring Summary

- [file:line] <change>

## Test Results

✅/❌

## Next Steps

- <suggestions>

Constraints

❌ Do not change business logic
❌ Do not add new features

Files

Just SKILL.md in skills/simplify of sd0xdev/sd0x-harness.

Open the folder on GitHubat commit c9a2036

Compare with similar skills

Simplify 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.

Simplify compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
Simplify this skillsd0xdev/sd0x-harness	192	—	~388	Automated safety check: Pass	MIT	yesterday
PonytailDavidObando/gsharp	564	8 repos	~1.7k	Automated safety check: Pass	MIT	today
Code Simplification for ego-litecitrolabs/ego-lite	17k	—	~1.2k	Automated safety check: Pass	MIT	14 days ago
Refactor Pass for Simplicitystar-history/star-history	9.6k	1 repos	~168	Automated safety check: Pass	MIT	25 days ago
RTK Rust Code Simplifierrtk-ai/rtk	83k	—	~1.1k	Automated safety check: Pass	Apache-2.0	today
Deslopmillionco/react-doctor	15k	—	~1.2k	Automated safety check: Pass	Custom licence	today

Similar skills

Ponytail
DavidObando/gsharp
Forces the laziest solution that actually works, simplest, shortest, most minimal.
564 GitHub starsUsed in 8 repos~1.7k tokens
DevelopmentAuto-check passed
Code Simplification for ego-lite
citrolabs/ego-lite
Finds and implements evidence-backed simplifications in the ego-lite repository, such as dead code, duplicated state and speculative abstractions, without hiding behavior changes.
17k GitHub stars~1.2k tokensUpdated 14 days ago
DevelopmentAuto-check passed
Refactor Pass for Simplicity
star-history/star-history
Perform a refactor pass focused on simplicity after recent changes. Use when the user asks for a refactor/cleanup pass, simplification, or dead-code removal…
9.6k GitHub starsUsed in 1 repo~168 tokens
DevelopmentAuto-check passed
RTK Rust Code Simplifier
rtk-ai/rtk
Reviews RTK's Rust code for over-engineering and verbose patterns, applying idioms like iterator chains and early returns while protecting a specific list of constraints from being simplified away.
83k GitHub stars~1.1k tokensUpdated today
DevelopmentAuto-check passed
Deslop
millionco/react-doctor
Simplify and refine recently modified code while preserving functionality.
15k GitHub stars~1.2k tokensUpdated today
DevelopmentAuto-check passed
Simplify Codebase
tt-a1i/simplify-codebase
Simplification audit or authorized codebase simplification whose stated objective is to remove accidental complexity.
504 GitHub stars~2.2k tokensUpdated 1 mo ago
DevelopmentAuto-check passed

Questions about Simplify

What does Simplify do?

Wrap-up refactoring — simplify code, eliminate duplication, preserve behavior. Simplify is an agent skill from sd0xdev/sd0x-harness.

When should I use Simplify?

Simplify fits situations like: tasks that involve Code simplification; tasks that involve Refactoring.

How do I install Simplify in Claude Code?

Run `npx skills add sd0xdev/sd0x-harness --skill simplify -a claude-code`. Or copy the skill folder (skills/simplify in sd0xdev/sd0x-harness) into .claude/skills/simplify in your project. Claude Code loads it when a task matches its description.

How do I install Simplify in Codex?

Run `npx skills add sd0xdev/sd0x-harness --skill simplify -a codex`. Or copy the skill folder (skills/simplify in sd0xdev/sd0x-harness) into .agents/skills/simplify in your project. Codex loads it when a task matches its description.

Can I use Simplify 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 sd0xdev/sd0x-harness --skill simplify -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/simplify, .gemini/skills/simplify, .github/skills/simplify and .opencode/skills/simplify in your project.

What does Simplify need to run?

SKILL.md names no scripts, command-line tools or credentials: Simplify is instructions for the agent only. Our summary lists: Node.js. Its frontmatter pre-approves these tools: Read, Grep, Glob, Edit, Bash(TEST_ENV=unit npx jest:*), Agent.

Does Simplify 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 Simplify 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. Review the folder before installing.

What licence does Simplify use?

Simplify 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 Simplify use?

About 388 tokens (SKILL.md is roughly 1.6k 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 Simplify?

Skills that share tags, products or a category with Simplify: Ponytail (DavidObando/gsharp, 564 stars), Code Simplification for ego-lite (citrolabs/ego-lite, 17k stars), Refactor Pass for Simplicity (star-history/star-history, 9.6k stars) and RTK Rust Code Simplifier (rtk-ai/rtk, 83k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Simplify?

sd0xdev (a GitHub user) maintains it in sd0xdev/sd0x-harness, which has 192 GitHub stars. The repository holds 91 skills in this directory. The repository was last updated on October 6, 2026.

Source: sd0xdev/sd0x-harness on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Install Simplify

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

Code Simplification

Trigger

When NOT to Use

Agent Dispatch

Primary: Code Simplification

Secondary: Refactoring Risk Review

Task

Output

Constraints

Files

Compare with similar skills

Similar skills

More from sd0xdev/sd0x-harness

Related

Questions about Simplify