itsPremkumar Markdown Linter & Formatter
Lint and auto-format Markdown: trailing whitespace, frontmatter validation, TOC generation, external link checks.
Keywords: markdown, lint, format, toc, cli, docs, python, open-source, agent, automation, MIT
Part of the itsPremkumar Hermes / OpenClaw / Paperclip agent stack — 31 free, MIT-licensed, CI-tested agent-native tools.
What it does
Markdown drift (broken links, missing TOC, bad frontmatter) hurts docs and SEO. Markdown Linter & Formatter solves this: Lint and auto-format Markdown: trailing whitespace, frontmatter validation, TOC generation, external link checks.
Best for: Docs owners, open-source maintainers, and agents generating Markdown.
Features
- Lint a Markdown file
- Auto-format/normalize
- Validate frontmatter
- Generate a TOC
- Check external links
Install
# Requires Python 3.8+. No pip install needed.
curl -O https://raw.githubusercontent.com/itsPremkumar/md-linter/main/md_linter.py
# Or copy the file anywhere — it's self-contained.
Quick start
python md_linter.py self-test # prove it works end-to-end
python md_linter.py check --help # check subcommand
python md_linter.py toc --help # toc subcommand
python md_linter.py links --help # links subcommand
python md_linter.py frontmatter --help # frontmatter subcommand
python md_linter.py format --help # format subcommand
Use cases
- Lint a Markdown file
- Auto-format/normalize
- Validate frontmatter
- Generate a TOC
- Check external links
Why choose this over alternatives
| Alternative | Why this skill is better |
|---|---|
| markdownlint | Adds TOC generation + frontmatter validation. |
| Manual TOC | One command. |
| Broken links | External-link checker. |
FAQ (SEO / AEO)
Q: TOC?
A: Yes — generate/insert a table of contents.
Q: External links?
A: --check-external validates them.
Q: Write?
A: --write reformats in place.
Q: Offline?
A: External-link check needs network; linting is offline.
Geo / local reach
Built and maintained by @itsPremkumar (Chennai, India · serving developers worldwide). Free for individuals and teams everywhere. Documentation in English; tool output is locale-neutral.
CI integration
# .github/workflows/verify.yml
name: Verify
on: [push]
jobs:
verify:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v4
- name: Self-test md-linter
run: python md_linter.py self-test
Support
Free + MIT-0 (free, modifiable, no attribution required). Sponsor if useful:
- GitHub Sponsors: https://github.com/sponsors/itsPremkumar
- Buy Me a Coffee: https://buymeacoffee.com/itsPremkumar
⭐ Star on GitHub