
Markdown Formatter
FreeTransform plain text into structured, reader-friendly markdown.
Free · Opens the source repo
What Markdown Formatter does
The Markdown Formatter skill is designed to enhance the readability and structure of plain text or markdown files. It focuses on formatting elements such as frontmatter, titles, summaries, headings, bold text, lists, and code blocks while preserving the original content. The skill operates under a core principle: it will only adjust formatting and correct obvious typos, ensuring that no content is added, deleted, or rewritten. This makes it particularly useful for users who want to improve the presentation of their documents without altering their original message.
The workflow consists of two main phases: analysis and formatting. Initially, the skill reads the specified file to detect its content type, determining whether it's plain text or markdown. Based on the detected format, it prompts the user to choose from several options, such as optimizing formatting, keeping the original structure, or applying typography fixes only. This flexibility allows users to tailor the output to their specific needs.
Once the user makes a selection, the skill analyzes the content from a reader's perspective, identifying highlights, key insights, and structural issues. It generates a detailed analysis report that serves as a blueprint for the formatting process. The final output is a well-structured markdown file, named with a -formatted.md suffix, that enhances the document's readability and organization.
This skill is ideal for writers, editors, and anyone who regularly works with markdown files and seeks to improve their document's layout and clarity. By automating the formatting process, it saves time and ensures a consistent presentation across various documents.
When to use it
Use this skill when you need to format markdown or plain text files for better readability and structure.
When not to use it
This skill is not suitable for users looking to rewrite or significantly alter the content of their documents.
What you can build with it
Formatting a Blog Post
Use this skill to enhance the layout of your blog post, making it more reader-friendly with proper headings and lists.
Preparing Documentation
Format technical documentation to improve clarity, ensuring that key points and code snippets are easily identifiable.
Beautifying Notes
Transform your raw notes into a structured markdown file that highlights important information and improves readability.
How to install Markdown Formatter
View source1. Install with the skills CLI
npx skills add jimliu/baoyu-skills/baoyu-format-markdown --agent claude-code2. Or install it manually
Download the skill folder and drop it into ~/.claude/skills/ for all projects, or .claude/skills/ to scope it to one repo. Restart Claude Code so it picks up the new skill.
Anthropic's agentic coding CLI, and the reference implementation of Agent Skills. Drop a skill folder into ~/.claude/skills and Claude Code loads it automatically whenever a task matches the skill's description. Claude Code docs
Inside SKILL.md
Written by jimliuMarkdown Formatter
Transforms plain text or markdown into well-structured, reader-friendly markdown. The goal is to help readers quickly grasp key points, highlights, and structure — without changing any original content.
Core principle: Only adjust formatting and fix obvious typos. Never add, delete, or rewrite content.
User Input Tools
When this skill prompts the user, follow this tool-selection rule (priority order):
- Prefer built-in user-input tools exposed by the current agent runtime — e.g.,
AskUserQuestion,request_user_input,clarify,ask_user, or any equivalent. - Fallback: if no such tool exists, emit a numbered plain-text message and ask the user to reply with the chosen number/answer for each question.
- Batching: if the tool supports multiple questions per call, combine all applicable questions into a single call; if only single-question, ask them one at a time in priority order.
Concrete AskUserQuestion references below are examples — substitute the local equivalent in other runtimes.
Script Directory
Scripts in scripts/ subdirectory. {baseDir} = this SKILL.md's directory path. Resolve ${BUN_X} runtime: if bun installed → bun; if npx available → npx -y bun; else suggest installing bun. Replace {baseDir} and ${BUN_X} with actual values.
| Script | Purpose |
|---|---|
scripts/main.ts | Main entry point with CLI options (uses remark-cjk-friendly for CJK emphasis) |
scripts/quotes.ts | Replace ASCII quotes with fullwidth quotes |
scripts/autocorrect.ts | Add CJK/English spacing via autocorrect |
Preferences (EXTEND.md)
Check EXTEND.md in priority order — the first one found wins:
| Priority | Path | Scope |
|---|---|---|
| 1 | .baoyu-skills/baoyu-format-markdown/EXTEND.md | Project |
| 2 | ${XDG_CONFIG_HOME:-$HOME/.config}/baoyu-skills/baoyu-format-markdown/EXTEND.md | XDG |
| 3 | $HOME/.baoyu-skills/baoyu-format-markdown/EXTEND.md | User home |
If none found, use defaults — no first-time setup required for this skill.
EXTEND.md supports:
| Setting | Values | Default | Description |
|---|---|---|---|
auto_select | true/false | false | Skip both title and summary selection, auto-pick best |
auto_select_title | true/false | false | Skip title selection only |
auto_select_summary | true/false | false | Skip summary selection only |
| Other | — | — | Default formatting options, typography preferences |
Usage
The workflow has two phases: Analyze (understand the content) then Format (apply formatting). Claude performs content analysis and formatting (Steps 1-5), then runs the script for typography fixes (Step 6).
Workflow
Step 1: Read & Detect Content Type
Read the user-specified file, then detect content type:
| Indicator | Classification |
|---|---|
Has --- YAML frontmatter | Markdown |
Has #, ##, ### headings | Markdown |
Has **bold**, *italic*, lists, code blocks, blockquotes | Markdown |
| None of above | Plain text |
If Markdown detected, use AskUserQuestion to ask:
Detected existing markdown formatting. What would you like to do?
1. Optimize formatting (Recommended)
- Analyze content, improve headings, bold, lists for readability
- Run typography script (spacing, emphasis fixes)
- Output: {filename}-formatted.md
2. Keep original formatting
- Preserve existing markdown structure
- Run typography script only
- Output: {filename}-formatted.md
3. Typography fixes only
- Run typography script on original file in-place
- No copy created, modifies original file directly
Based on user choice:
- Optimize: Continue to Step 2 (full workflow)
- Keep original: Skip to Step 5, copy file then run Step 6
- Typography only: Skip to Step 6, run on original file directly
Step 2: Analyze Content (Reader's Perspective)
Read the entire content carefully. Think from a reader's perspective: what would help them quickly understand and remember the key information?
Produce an analysis covering these dimensions:
2.1 Highlights & Key Insights
- Core arguments or conclusions the author makes
- Surprising facts, data points, or counterintuitive claims
- Memorable quotes or well-phrased sentences (golden quotes)
2.2 Structure Assessment
- Does the content have a clear logical flow? What is it?
- Are there natural section boundaries that lack headings?
- Are there long walls of text that could benefit from visual breaks?
2.3 Reader-Important Information
- Actionable advice or takeaways
- Definitions, explanations of key concepts
- Lists or enumerations buried in prose
- Comparisons or contrasts that would be clearer as tables
2.4 Formatting Issues
- Missing or inconsistent heading hierarchy
- Paragraphs that mix multiple topics
- Parallel items written as prose instead of lists
- Code, commands, or technical terms not marked as code
- Obvious typos or formatting errors
Save analysis to file: {original-filename}-analysis.md
The analysis file serves as the blueprint for Step 3. Use this format:
# Content Analysis: {filename}
## Highlights & Key Insights
- [list findings]
## Structure Assessment
- Current flow: [describe]
- Suggested sections: [list heading candidates with brief rationale]
## Reader-Important Information
- [list actionable items, key concepts, buried lists, potential tables]
## Formatting Issues
- [list specific issues with location references]
## Typos Found
- [list any obvious typos with corrections, or "None found"]
Step 3: Check/Create Frontmatter, Title & Summary
Check for YAML frontmatter (--- block). Create if missing.
| Field | Processing |
|---|---|
title | See Title Generation below |
slug | Infer from file path or generate from title |
summary | One-sentence concise summary (see Summary Generation below) |
description | Longer descriptive summary (see Summary Generation below) |
coverImage | Check if imgs/cover.png exists in same directory; if so, use relative path |
Title Generation
Whether or not a title already exists, run the title optimization flow unless auto_select_title is set.
Preparation — read the full text and extract:
- Core argument (one sentence: "what is this article about?")
- Most impactful opinion or conclusion
- Reader pain point or curiosity trigger
- Most memorable metaphor or golden quote
Generate candidates using formulas from references/title-formulas.md:
- Select the 2-3 best-matching hook formulas based on the article's content, tone, and structure (see "When to pick each formula" in the reference)
- Generate 1-2 straightforward titles (descriptive or declarative, no formula — clear and accurate)
- If the user specifies a direction (e.g., "make it suspenseful"), prioritize that direction
- Total: 4-5 candidates
Present via AskUserQuestion:
Pick a title:
1. [Hook title A] — (recommended) [formula name]
2. [Hook title B] — [formula name]
3. [Hook title C] — [formula name]
4. [Straightforward title D] — straightforward
5. [Straightforward title E] — straightforward
Enter number, or type a custom title:
Put the strongest hook first and mark it (recommended). See references/title-formulas.md for principles and prohibited patterns.
If the first line is an H1, extract it to frontmatter and remove it from the body. If frontmatter already has a title, include it as context but still generate fresh candidates — the existing title may be weak.
Skip behavior: If auto_select: true or auto_select_title: true, skip the user prompt and use the top candidate directly.
Summary Generation
Generate two versions directly (no user selection), both stored in frontmatter:
| Field | Length | Purpose |
|---|---|---|
summary | 1 sentence, ~50-80 chars | Concise hook — for feeds, social sharing, SEO meta |
description | 2-3 sentences, ~100-200 chars | Richer context — for article previews, newsletter blurbs |
Principles:
- Convey core value to the reader, not just the topic
- Use concrete details (numbers, outcomes, specific methods) over vague descriptions
summaryshould be punchy and self-contained;descriptioncan expand with supporting details- If frontmatter already has
summaryordescription, keep the existing one and only generate the missing field
Prohibited patterns:
- "This article introduces...", "This article explores..."
- Pure topic description without value proposition
- Repeating the title in different words
Once the title is in frontmatter, the body should NOT contain an H1 (avoid duplication).
Step 4: Format Content
Apply formatting guided by the Step 2 analysis. The goal is making the content scannable and the key points impossible to miss.
Formatting toolkit:
| Element | When to use | Format |
|---|---|---|
| Headings | Natural topic boundaries, section breaks | ##, ### hierarchy |
| Bold | Key conclusions, important terms, core takeaways | **bold** |
| Unordered lists | Parallel items, feature lists, examples | - item |
| Ordered lists | Sequential steps, ranked items, procedures | 1. item |
| Tables | Comparisons, structured data, option matrices | Markdown table |
| Code | Commands, file paths, technical terms, variable names | `inline` or fenced blocks |
| Blockquotes | Notable quotes, important warnings, cited text | > quote |
| Separators | Major topic transitions | --- |
Formatting principles — what NOT to do:
- Do NOT add sentences, explanations, or commentary
- Do NOT delete or shorten any content
- Do NOT rephrase or rewrite the author's words
- Do NOT add headings that editorialize (e.g., "Amazing Discovery" — use neutral descriptive headings)
- Do NOT over-format: not every sentence needs bold, not every paragraph needs a heading
Formatting principles — what TO do:
- Preserve the author's voice, tone, and every word
- Bold key conclusions and core takeaways — the sentences a reader would highlight
- Extract parallel items from prose into lists only when the structure is clearly there
- Add headings where the topic genuinely shifts — prefer vivid, specific headings over generic ones (e.g., "3 天搞定 vs 传统方案" over "方案对比")
- Use tables for comparisons or structured data buried in prose
- Use blockquotes for golden quotes, memorable statements, or important warnings
- Fix obvious typos (based on Step 2 findings)
Step 5: Save Formatted File
Save as {original-filename}-formatted.md
Backup existing file:
if [ -f "{filename}-formatted.md" ]; then
mv "{filename}-formatted.md" "{filename}-formatted.backup-$(date +%Y%m%d-%H%M%S).md"
fi
Step 6: Execute Typography Script
Run the formatting script on the output file:
${BUN_X} {baseDir}/scripts/main.ts {output-file-path} [options]
Script Options:
| Option | Short | Description | Default |
|---|---|---|---|
--quotes | -q | Replace ASCII quotes with fullwidth quotes "..." | false |
--no-quotes | Do not replace quotes | ||
--spacing | -s | Add CJK/English spacing via autocorrect | true |
--no-spacing | Do not add CJK/English spacing | ||
--emphasis | -e | Fix CJK emphasis punctuation issues | true |
--no-emphasis | Do not fix CJK emphasis issues |
Examples:
# Default: spacing + emphasis enabled, quotes disabled
${BUN_X} {baseDir}/scripts/main.ts article.md
# Enable all features including quote replacement
${BUN_X} {baseDir}/scripts/main.ts article.md --quotes
# Only fix emphasis issues, skip spacing
${BUN_X} {baseDir}/scripts/main.ts article.md --no-spacing
Script performs (based on options):
- Fix CJK emphasis/bold punctuation issues (default: enabled)
- Add CJK/English mixed text spacing via autocorrect (default: enabled)
- Replace ASCII quotes with fullwidth quotes (default: disabled)
- Format frontmatter YAML (always enabled)
Step 7: Completion Report
Display a report summarizing all changes made:
**Formatting Complete**
**Files:**
- Analysis: {filename}-analysis.md
- Formatted: {filename}-formatted.md
**Content Analysis Summary:**
- Highlights found: X key insights
- Golden quotes: X memorable sentences
- Formatting issues fixed: X items
**Changes Applied:**
- Frontmatter: [added/updated] (title, slug, summary)
- Headings added: X (##: N, ###: N)
- Bold markers added: X
- Lists created: X (from prose → list conversion)
- Tables created: X
- Code markers added: X
- Blockquotes added: X
- Typos fixed: X [list each: "original" → "corrected"]
**Typography Script:**
- CJK spacing: [applied/skipped]
- Emphasis fixes: [applied/skipped]
- Quote replacement: [applied/skipped]
Adjust the report to reflect actual changes — omit categories where no changes were made.
Notes
- Preserve original writing style and tone
- Specify correct language for code blocks (e.g.,
python,javascript) - Maintain CJK/English spacing standards
- The analysis file is a working document — it helps maintain consistency between what was identified and what was formatted
Extension Support
Custom configurations via EXTEND.md. See Preferences section for paths and supported options.
Frequently asked questions about Markdown Formatter
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