mcpbeat

Ctf Writeup

ljagiello/ctf-writeup

Generates a single standardized submission-style CTF writeup for competition handoff and organizer review. Use after solving a CTF challenge to document the solution steps, tools used, and lessons learned in a structured format.

1k tokens
context cost
the whole folder, loaded on every use
1
files
instructions only
0
copies elsewhere
how many repositories repackaged it
2908
stars on the repo
on the repository, not the skill itself

Install

one command, takes just this skill from the repository
npx skills add https://github.com/ljagiello/ctf-skills --skill ctf-writeup

The instruction itself

9 sections, as written by the author

CTF Write-up Generator

Generate a standardized submission-style CTF writeup for a solved challenge.

Default behavior:

  • During an active competition, optimize for speed, clarity, and reproducibility
  • Keep writeups short enough that a teammate or organizer can validate the solve quickly
  • Always produce a submission-style writeup
  • Prefer one complete solve script from challenge data to final flag

Workflow

Step 1: Gather Information

Collect the following from the current session, challenge files, and user input:

  • Challenge metadata — name, CTF event, category, difficulty, points, flag format
  • Solution artifacts — exploit scripts, payloads, screenshots, command output
  • Timeline — key steps taken, dead ends, pivots
# Scan for exploit scripts and artifacts
find . -name '*.py' -o -name '*.sh' -o -name 'exploit*' -o -name 'solve*' | head -20
# Check for flags in output files
grep -rniE '(flag|ctf|eno|htb|pico)\{' . 2>/dev/null

Step 2: Generate Write-up

Write the writeup file as writeup.md (or writeup-<challenge-name>.md) using the submission template below.


Templates

Submission Format

---
title: "<Challenge Name>"
ctf: "<CTF Event Name>"
date: YYYY-MM-DD
category: web|pwn|crypto|reverse|forensics|osint|malware|misc
difficulty: easy|medium|hard
points: <number>
flag_format: "flag{...}"
author: "<your name or team>"
---

# <Challenge Name>

## Summary

<1-2 sentences: what the challenge was and the core technique. Keep it direct.>

## Solution

### Step 1: <Action>

<Explain the key observation in 3-8 short lines. Keep it direct.>

\`\`\`python
<one complete solving script from provided challenge data to printing the final flag>
\`\`\`

### Step 2: <Action> (optional)

<Only add this when a second short step genuinely helps readability, such as separating the core observation from final verification.>

### Step 3: <Action> (optional)

<Use only if the challenge really needs it. Keep the total number of steps small.>

## Flag

\`\`\`
flag{example_flag_here}
\`\`\`

Guidance:

  • Prefer 1-3 short steps total
  • Keep code to the smallest complete solving script
  • Do not split "recover secret", "derive key", and "decrypt flag" into separate partial snippets
  • The script should start from the challenge data and end by printing the flag
  • Avoid long background sections
  • Avoid dead ends unless they explain a key pivot
  • Avoid multiple alternative solves; pick one clean path
  • Redact the flag only if the user explicitly asks for redaction

Best Practices Checklist

Before finalizing the writeup, verify:

  • [ ] Metadata complete — title, CTF, date, category, difficulty, points, author all filled
  • [ ] Flag handling matches request — keep the real flag unless the user asked for redaction
  • [ ] Reproducible steps — a reader can follow your writeup and reproduce the solution
  • [ ] Code is runnable — exploit scripts include all imports, correct variable names, and comments
  • [ ] No sensitive data — no real credentials, API keys, or private infrastructure details
  • [ ] Length stays concise — the writeup is short enough for fast review
  • [ ] Tools and versions noted — mention specific tool versions if behavior depends on them
  • [ ] Proper attribution — credit teammates, referenced writeups, or tools that were essential
  • [ ] Grammar and formatting — consistent heading levels, code blocks have language tags

Quality Guidelines

DO:

  • Explain just enough for fast verification
  • Include one complete solving path, not multiple alternative routes
  • Include one complete script that goes all the way to the final flag
  • Show actual output (truncated if very long) to prove the approach worked
  • Tag code blocks with language (python, bash, sql, etc.)
  • Keep the main path front-loaded so a reader can validate it quickly

DON'T:

  • Copy-paste raw terminal dumps without explanation
  • Paste several partial snippets that force the reader to reconstruct the final solve
  • Leave placeholder text in the final writeup
  • Include irrelevant tangents that don't contribute to the solution
  • Assume the reader knows the specific challenge setup

Challenge

$ARGUMENTS

How to use it

Copy the folder

Take ljagiello/ctf-writeup from the repository into ~/.claude/skills for personal use, or into .claude/skills inside a project.

Check the name does not clash

The agent identifies a skill by the name field in its header. Two skills with the same name cannot sit side by side — one of them will be ignored.