DeMarkX Markdown Fixer GitHub Action

Deterministic Markdown repair engine for GitHub CI. Auto-heals syntax, enforces GFM compliance, and applies safe fixes back to your branch.

What is DeMarkX? Most Markdown tools just complain about errors. DeMarkX heals them.

It uses an AST-based repair engine to identify structural issues and automatically fix them with full determinism. It is idempotent, running it once has the same effect as running it ten times.

Key Features

• Heals Headers: Fixes missing spaces after # (e.g., #Title → # Title).
• Normalizes Structure: Ensures consistent spacing between blocks and list items.
• Repair Fences: Auto-closes unclosed code blocks and normalizes backtick counts.
• List Alignment: Corrects malformed numbered (1.Item) and bulleted (-Item) lists.
• CI Native: Designed to run on every Pull Request or Push.
• Safe Fixes Only: High-confidence repairs that won't mangle your content.

Quickstart

Add a

.github/workflows/demarkx.yml

file to your repository:

 name: DeMarkX Markdown Repair

on:
  pull_request:
    branches: [ main ]
  push:
    branches: [ main ]

jobs:
  heal:
    runs-on: ubuntu-latest
    permissions:
      contents: write # Required for auto-committing fixes
    steps:

      - uses: actions/checkout@v4

      - name: Heal Markdown
        uses: SheikhJaveed/demarkx-action@v1.0.0
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          apply-safe-fixes: true
          dry-run: false

Configuration

Input Description Default

Input	Description	Default
github-token	Required. The repository GITHUB_TOKEN	N/A
apply-safe-fixes	Automatically repair and commit safe fixes	true
dry-run	Report issues without modifying files	false
max-files	Limit number of files processed per run	50
skip-paths	Comma-separated paths to ignore	node_modules

How it works

DeMarkX does not use regex-based patching.

It parses Markdown into an Abstract Syntax Tree (AST), applies deterministic architectural repairs, and regenerates a clean Markdown string.

Safe vs. Inferred Fixes

• Safe Fixes: Standard-compliant repairs like missing spaces or broken fences.
• Inferred Fixes: Logic corrections where the engine "guesses" your intent (e.g., deeply nested list re-alignment).

Default behavior only applies Safe Fixes to ensure your docs are never corrupted.