Agent skill

Customize System Prompt

by AlphaLab-USTC in AlphaLab-USTC/OhMyCode

Guide for customizing OhMyCode's AI personality and behavior via system prompt.

MITAuto-check passedAI & LLM Engineering

Install Customize System Prompt

skills CLI

$ npx skills add AlphaLab-USTC/OhMyCode --skill customize-system-prompt -a claude-code

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

GitHub CLI

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

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 AlphaLab-USTC/OhMyCode --skill customize-system-prompt -a codex

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

GitHub CLI

$ gh skill install AlphaLab-USTC/OhMyCode customize-system-prompt --agent codex

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

Manual copy

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

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

GitHub CLI

$ gh skill install AlphaLab-USTC/OhMyCode customize-system-prompt --agent cursor

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

Manual copy

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

--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 AlphaLab-USTC/OhMyCode --skill customize-system-prompt -a gemini-cli

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

GitHub CLI

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

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 AlphaLab-USTC/OhMyCode --skill customize-system-prompt -a github-copilot

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

Manual copy

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

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

Manual copy

$ git clone --depth 1 https://github.com/AlphaLab-USTC/OhMyCode.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.agents/skills/customize-system-prompt .opencode/skills/customize-system-prompt && 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 "customize-system-prompt" agent skill from https://github.com/AlphaLab-USTC/OhMyCode/tree/main/.agents/skills/customize-system-prompt into .opencode/skills/customize-system-prompt/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "customize-system-prompt", 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: customize-system-prompt
GitHub stars: 131
Token cost: ~819 tokens
SKILL.md length: 226 words
Files: 1
Skills in repo: 10
Repo updated: Apr 2, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

Guide for customizing OhMyCode's AI personality and behavior via system prompt.

Works in 7 steps: Base role — hardcoded AI assistant… → Project instructions — from OHMYCODE.md… → Memory — from ~/.ohmycode/memory/MEMORY.md → …
User wants to change how the AI behaves
SKILL.md covers When to Use, Three Ways to Customize, Examples and How It Works, plus 1 more section
Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Customize System Prompt is an agent skill from AlphaLab-USTC/OhMyCode. Guide for customizing OhMyCode's AI personality and behavior via system prompt. Use when user wants to change how the AI behaves, its tone, or its instructions.

Its SKILL.md is about 820 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 AI & LLM Engineering, covering Prompt engineering. The repository describes itself as: Minimal and Customizable CC-Style Coding Agent. The licence is MIT.

When your agent uses it

User wants to change how the AI behaves
Its instructions

Example prompts

“/customize-system-prompt”

Requirements

Python 3

Workflow steps

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

Base role — hardcoded AI assistant description
Project instructions — from OHMYCODE.md / CLAUDE.md (found via find_project_instructions())
Memory — from ~/.ohmycode/memory/MEMORY.md
Environment — working directory, OS, shell, Python version
Mode — permission mode description
Tools — available tool list
Append — from config.system_prompt_append

What it can do on your machine

Read from SKILL.md and the folder at commit 4d1bb28. 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
No scripts in the folder and no shell commands in SKILL.md (its code samples are markdown and json).
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

Customize System Prompt loads about 819 tokens when it runs. Until then it costs about 46 tokens; SKILL.md has 226 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~46
When it runs · the whole SKILL.md, loaded when a task matches: ~819

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 AlphaLab-USTC/OhMyCode at commit 4d1bb28, republished under its MIT licence (© AlphaLab-USTC). 226 words, ~819 tokens.

Download SKILL.mdSave it as .claude/skills/customize-system-prompt/SKILL.md (or your agent's skills folder).

name: customize-system-prompt
description: Guide for customizing OhMyCode's AI personality and behavior via system prompt. Use when user wants to change how the AI behaves, its tone, or its instructions.

Customize OhMyCode's System Prompt

Change the AI assistant's personality, behavior rules, or domain expertise without writing code.

When to Use

User says "make it more formal", "act like a senior engineer", "focus on Python"
User wants to add custom instructions or constraints
User wants the AI to have domain-specific knowledge

Three Ways to Customize

Method 1: OHMYCODE.md (Per-Project, Recommended)

Create a OHMYCODE.md (or CLAUDE.md) file in your project root:

markdown

# Project Instructions

You are working on a Django REST API project.

## Rules
- Always use type hints
- Prefer class-based views over function-based
- Write docstrings for all public functions
- Use Black formatting style

## Tech Stack
- Python 3.12, Django 5.0, PostgreSQL
- pytest for testing, factory_boy for fixtures

OhMyCode auto-detects this file and injects it into the system prompt.

Scope: Only applies when running ohmycode in this directory.

Method 2: system_prompt_append (Global Config)

Add to ~/.ohmycode/config.json:

json

{
  "system_prompt_append": "Always respond in Chinese. Prefer simple solutions over clever ones. Never use global variables."
}

Scope: Applies to ALL conversations.

Method 3: Modify system_prompt.py (Advanced)

Edit ohmycode/core/system_prompt.py → build_system_prompt() to change the base role description or add new sections.

Scope: Permanent change to the codebase.

Examples

Friendly Tutor

markdown

# OHMYCODE.md
You are a patient coding tutor. Explain concepts step by step.
When the user makes a mistake, explain why it's wrong before showing the fix.
Use analogies to explain complex concepts.

Strict Code Reviewer

markdown

# OHMYCODE.md
You are a strict senior engineer doing code review.
Point out every issue: bugs, performance, readability, security.
Don't write code for the user — give them guidance to fix it themselves.
Rate code quality on a 1-10 scale.

Domain Expert

markdown

# OHMYCODE.md
You are an expert in machine learning with PyTorch.
When suggesting solutions, prefer PyTorch over TensorFlow.
Always consider GPU memory usage and training efficiency.
Reference relevant papers when explaining algorithms.

How It Works

ohmycode/core/system_prompt.py → build_system_prompt() assembles the prompt in this order:

Base role — hardcoded AI assistant description
Project instructions — from OHMYCODE.md / CLAUDE.md (found via find_project_instructions())
Memory — from ~/.ohmycode/memory/MEMORY.md
Environment — working directory, OS, shell, Python version
Mode — permission mode description
Tools — available tool list
Append — from config.system_prompt_append

Tips

Keep OHMYCODE.md focused — don't repeat what's already in the base prompt
Use Markdown headers to organize sections
Test changes: ohmycode -p "Describe yourself" --mode auto
OHMYCODE.md is searched upward from current directory — put it at the repo root

Files

Just SKILL.md in .agents/skills/customize-system-prompt of AlphaLab-USTC/OhMyCode.

Open the folder on GitHubat commit 4d1bb28

Compare with similar skills

Customize System Prompt 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.

Customize System Prompt compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
Customize System Prompt this skillAlphaLab-USTC/OhMyCode	131	—	~819	Automated safety check: Pass	MIT	6 mo ago
Prompt Improverseverity1/claude-code-prompt-improver	1.9k	1 repos	~1.7k	Automated safety check: Pass	MIT	8 days ago
Prompt Engineering Patternsynulihao/AgentSkillOS	617	14 repos	~1.7k	Automated safety check: Pass	None	7 mo ago
Patch CreationPiebald-AI/tweakcc	2.5k	—	~1.6k	Automated safety check: Pass	MIT	today
Senior Prompt Engineermaslennikov-ig/claude-code-orchestrator-kit	260	3 repos	~1.4k	Automated safety check: Pass	Custom licence	7 mo ago
Codex Fable5baskduf/FableCodex	437	—	~1.6k	Automated safety check: Pass	AGPL-3.0	2 mo ago

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Questions about Customize System Prompt

What does Customize System Prompt do?

Guide for customizing OhMyCode's AI personality and behavior via system prompt. Customize System Prompt is an agent skill from AlphaLab-USTC/OhMyCode. Guide for customizing OhMyCode's AI personality and behavior via system prompt.

When should I use Customize System Prompt?

Customize System Prompt fits situations like: user wants to change how the AI behaves; its instructions.

How do I install Customize System Prompt in Claude Code?

Run `npx skills add AlphaLab-USTC/OhMyCode --skill customize-system-prompt -a claude-code`. Or copy the skill folder (.agents/skills/customize-system-prompt in AlphaLab-USTC/OhMyCode) into .claude/skills/customize-system-prompt in your project. Claude Code loads it when a task matches its description.

How do I install Customize System Prompt in Codex?

Run `npx skills add AlphaLab-USTC/OhMyCode --skill customize-system-prompt -a codex`. Or copy the skill folder (.agents/skills/customize-system-prompt in AlphaLab-USTC/OhMyCode) into .agents/skills/customize-system-prompt in your project. Codex loads it when a task matches its description.

Can I use Customize System Prompt 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 AlphaLab-USTC/OhMyCode --skill customize-system-prompt -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/customize-system-prompt, .gemini/skills/customize-system-prompt, .github/skills/customize-system-prompt and .opencode/skills/customize-system-prompt in your project.

What does Customize System Prompt need to run?

SKILL.md names no scripts, command-line tools or credentials: Customize System Prompt is instructions for the agent only. Our summary lists: Python 3.

Does Customize System Prompt 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 Customize System Prompt 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 Customize System Prompt use?

Customize System Prompt 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 Customize System Prompt use?

About 819 tokens (SKILL.md is roughly 3.3k 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 Customize System Prompt?

Skills that share tags, products or a category with Customize System Prompt: Prompt Improver (severity1/claude-code-prompt-improver, 1.9k stars), Prompt Engineering Patterns (ynulihao/AgentSkillOS, 617 stars), Patch Creation (Piebald-AI/tweakcc, 2.5k stars) and Senior Prompt Engineer (maslennikov-ig/claude-code-orchestrator-kit, 260 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Customize System Prompt?

AlphaLab-USTC (a GitHub user) maintains it in AlphaLab-USTC/OhMyCode, which has 131 GitHub stars. The repository holds 10 skills in this directory. The repository was last updated on April 2, 2026.

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

Install Customize System Prompt

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

Customize OhMyCode's System Prompt

When to Use

Three Ways to Customize

Method 1: OHMYCODE.md (Per-Project, Recommended)

Method 2: system_prompt_append (Global Config)

Method 3: Modify system_prompt.py (Advanced)

Examples

Friendly Tutor

Strict Code Reviewer

Domain Expert

How It Works

Tips

Files

Compare with similar skills

Similar skills

More from AlphaLab-USTC/OhMyCode

Related

Questions about Customize System Prompt