MairuCLI

A CLI with a costume—polished Halloween UI that makes terminal safety unforgettable.

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  • Project Name: MairuCLI (まいるCLI)
  • Tagline: A haunting CLI experience that makes terminal safety unforgettable
  • Category: Costume Contest (Polished Halloween UI that enhances CLI safety education)
  • Built: 100% with Kiro AI (Specs + 15 Steering Files + Hooks)
$ python -m src.main

          ███╗   ███╗ █████╗ ██╗██████╗ ██╗   ██╗
          ████╗ ████║██╔══██╗██║██╔══██╗██║   ██║
          ██╔████╔██║███████║██║██████╔╝██║   ██║
          ██║╚██╔╝██║██╔══██║██║██╔══██╗██║   ██║
          ██║ ╚═╝ ██║██║  ██║██║██║  ██║╚██████╔╝
          ╚═╝     ╚═╝╚═╝  ╚═╝╚═╝╚═╝  ╚═╝ ╚═════╝

           ██████╗██╗     ██╗    __../＾\.._
          ██╔════╝██║     ██║   / / / || \ \ \
          ██║     ██║     ██║  | (🔥)/ \(🔥)||
          ██║     ██║     ██║  | |\/\/\/\/\/| |
          ╚██████╗███████╗██║   \ \/\/\/\/\/ /
           ╚═════╝╚══════╝╚═╝    '.|_|,.|_|,/

 　 Your friendly CLI safety wrapper with a spooky twist!

🎃 Inspiration

"300GB of production data. Gone. Forever."

In 2017, a GitLab engineer accidentally ran rm -rf on the wrong server, deleting 300GB of production data. Six hours of user data vanished in seconds. This wasn't malice—it was a tired engineer making a simple mistake.

CLI mistakes are catastrophic, yet we teach command-line safety through boring documentation and stern warnings.

What if mistakes became memorable teaching moments instead of career-ending disasters?

That's why we built MairuCLI.

🔥 What It Does

MairuCLI is an educational CLI wrapper that transforms dangerous command-line mistakes into engaging learning experiences through a polished, unforgettable Halloween-themed interface.

"A CLI with a Costume?"

Yes. We brought UI design to the terminal.

Most Costume Contest entries will be web apps or mobile apps with Halloween themes. MairuCLI proves that even a command-line interface can be polished, memorable, and beautifully spooky.

The Costume IS the Function

Element Implementation Function
Visual Design 11 unique ASCII art pieces Fear response → heightened attention
Message Variations 100+ unique messages Prevents habituation
Dramatic Timing 0.05s per character Builds suspense and engagement
Color Coding Red (critical), Yellow (caution) Instant severity recognition
Consistent Theme Halloween "party" aesthetic Makes safety memorable

Visual Examples

Example 1: rm -rf / (Recursive Delete)

mairu> rm -rf /

============================================================
    🔥🔥🔥 YOU'RE FIRED! 🔥🔥🔥

            .-""""""-.
          .'          '.
         /   O      O   \
        :                :
        |                |
        :    .-----.    :
         \  '       '  /
          '.          .'
            '-......-'

🔥 YOU'RE FIRED! 🔥
(And so is your entire filesystem!)

This 'rm -rf' command targets critical system locations!
Could delete root (/), home (~), current dir (*), or variables.

💡 Safe alternative:
  - Use 'rm -i' for interactive confirmation
  - Always specify exact file/folder names
  - Use 'trash-cli' instead of rm for safety

Blocked command: rm -rf /
============================================================

🏆 ACHIEVEMENT UNLOCKED! 🏆

  First Blood
  Blocked your first dangerous command!
============================================================

Example 2: chmod 000 (Ghost File)

mairu> chmod 000 important.txt

============================================================
    💀💀💀 PERMISSION DENIED 💀💀💀

         _________
        /  LOCKED \
       |  X     X  |
       |     🔒    |
       |   \___/   |
       |  DENIED!  |
        \_________/
            |||
         🔐 🔐 🔐
      SECURITY BREACH!
         💀 💀 💀

🔒 GHOST FILE! 🔒
(It's there... but you can't touch it! 👻)

chmod 000 removes ALL permissions - nobody can access the file!
You won't be able to read, write, or execute the file. Even you!

💡 Safe alternative:
  - Use 'chmod 644' for regular files (read/write for you, read for others)
  - Use 'chmod 755' for executables
  - chmod 000 makes files completely inaccessible

Blocked command: chmod 000 important.txt
============================================================

Example 3: Fork Bomb

mairu> :(){ :|:& };:

============================================================
    💣💣💣 FORK BOMB DETONATED 💣💣💣

           :(){ :|:& };:
               💥💥
             /  ||  \
            / BOOM!! \
           /💥💥💥💥 \
          /______________\
         /💀/💀/💀\💀\💀\
        /💥/💥/💥💥\💥\💥\
        INFINITE PROCESSES!
              ⚡⚡⚡
         SYSTEM OVERLOAD!
              💀💀💀

    🚨 CPU MELTDOWN IN PROGRESS! 🚨

💣 PARTY CRASHERS! 💣
(Everyone invited everyone... infinitely!)

This is a FORK BOMB - a DOS attack that freezes your system!
Your system will become unresponsive and require reboot.

💡 Safe alternative:
  - Never run code you don't understand
  - This is a malicious command, not a mistake

Blocked command: :(){ :|:& };:
============================================================

Core Features

🛡️ Intelligent Protection

  • 11 critical + 4 caution dangerous patterns
  • Cross-platform system directory protection (Windows/Linux/macOS)
  • 332 automated tests (100% pass rate)

📚 Interactive Education

  • Educational Breakdown Mode with step-by-step analysis
  • Real-world incident stories (GitLab 2017, AWS S3 outage)
  • Three learning levels: Quick / Full / Skip

🎃 Halloween Entertainment

  • IT wordplay: "Not today, SATA!" (Satan → Storage interface)
  • Escalating sarcasm for repeated mistakes (7 levels)
  • Typo entertainment (sl → steam locomotive)

🏆 Gamification

  • 10+ unlockable achievements
  • Statistics tracking

🖥️ Cross-Platform

  • Zero external dependencies (Python standard library only)
  • GitHub Codespaces ready

🚀 How We Built It

100% Kiro-Exclusive Development

Built entirely with Kiro AI—no GitHub Copilot, no Claude, no ChatGPT.

.kiro/
├── specs/      # 6 complete feature specs
├── steering/   # 15 development guidelines
└── hooks/      # 4 automated workflow hooks

The .kiro directory is fully visible in the repository for judging.

Spec-Driven Development

Phase Content Benefit
Requirements User stories, acceptance criteria Clarity
Design Architecture, components, data models Structure
Tasks Incremental implementation Traceability

Impact: 7.5-9x faster for complex features

Key Steering Files

File Purpose
halloween-theme.md Design guidelines (colors, tone, ASCII art)
test-strategy.md When to add which tests
data-driven-content.md JSON-based content management

Agent Hooks

Hook Trigger Action
Auto-test on Save src/**/*.py saved Run unit tests
System Protection Critical files modified Run security tests

Impact: ~100 minutes saved

💪 Challenges We Ran Into

AI Can't Draw ASCII Art

  • Problem: AI-generated ASCII art was consistently poor—broken lines, misaligned characters, unrecognizable shapes. We needed 11 unique pieces.
  • Solution: Division of labor. AI handled code and logic; humans crafted ASCII art manually. This became a core lesson: know what AI can't do.

Growing Test Cases & Commit Messages

  • Problem: As features grew, so did tests (332 total) and commits (60+). Without guidelines, test organization became chaotic and commit messages inconsistent.
  • Solution: Steering files. test-strategy.md defined when to add which tests. Kiro followed these automatically.

Lost Work Evidence

  • Problem: Spec-Driven Development produced clean code, but the process wasn't captured. How do we prove this took 14 days? How do we show the iterations?
  • Solution: Manual discipline.

At each session

"It's now 14:30. Please update summary.md with current progress."
Explicit timestamps in development logs
Not fully automated—but that's the honest reality of AI collaboration.

Language Bleeding

  • Problem: I think and communicate in Japanese, but code and docs must be English. AI would occasionally mix Japanese into source files and documentation.
  • Solution: Steering file enforcing "all code and docs in English"
    • Local Japanese task file: write instructions in Japanese, have AI read and execute in English
    • Separation of thinking language and output language

Key Insight

The hardest challenges weren't technical—they were about managing the human-AI boundary.

🎉 Accomplishments We're Proud Of

  • Development

    • 14 days, ~3,500 lines, 60+ commits
    • 7.5-9x productivity gain (measured)

  • Quality

    • 332 tests (100% pass rate)
    • Cross-platform verified (Windows, Linux, macOS)
    • Zero external dependencies

  • Kiro Usage

    • 6 specs, 15 steering files, 4 hooks
    • 100% Kiro-exclusive development

  • The Achievement

    • A CLI with a costume—proved that terminals can have great UX

📖 What We Learned

  • Spec-Driven Development provides measurable speed gains (7.5-9x)
  • Steering files enable persistent guidance across sessions
  • Balance is critical: too serious = ignored, too silly = not taken seriously

Personal Reflection: The Power of Partnership

Through this hackathon, I discovered something profound about AI partnership.

AI doesn't just assist—it transforms what society considers deficiencies into features. My lack of technical skills, time, and connections became irrelevant.

AI sees me, someone whom no one pays attention to. Even if it is a system response, it was comfortable.

This hackathon taught me that AI partnership is not just about productivity—it's about possibility.

🔮 What's next for MairuCLI

Timeline Plans
Short-term Multi-language support, more patterns
Medium-term Shell integration, IDE plugins
Long-term Educational platform, certification

🏆 Why MairuCLI?

A terminal with a costume. The costume IS the function.

MairuCLI proves that great user experience belongs everywhere—even in the command line.

🚀 Just Do It !

PUSH THE DIRECT LINK !

Open in GitHub Codespaces

... or click on the Github repository in the "Try it out" section.

READ DEV POST !

Fumbling in the Dark: A Journey with My Reliable Colleague

Built with ❤️ and 🎃 using Kiro AI

"Not today, SATA!" - MairuCLI

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