mdschema

A declarative schema-based Markdown documentation validator that helps maintain consistent documentation structure across projects.

This README file itself is an example of how to use mdschema to validate and generate documentation.

mdschema check README.md --schema ./examples/README-schema.yml
✓ No violations found

Features

• 🔍 Schema-driven validation - Define your documentation structure in simple YAML
• 🌳 Hierarchical structure - Support for nested sections and complex document layouts
• 📝 Template generation - Generate markdown templates from your schemas
• 🔧 Rule-based validation - Validate headings, code blocks, required text, and structure order
• 🎯 Context-aware - Uses AST parsing for accurate validation without string matching guesswork
• 🚀 Fast and lightweight - Single binary with no dependencies
• 💻 Cross-platform - Works on Linux, macOS, and Windows

Installation

Go Install

go install github.com/jackchuka/mdschema/cmd/mdschema@latest

From Source

git clone https://github.com/jackchuka/mdschema.git
cd mdschema
go build -o mdschema ./cmd/mdschema

Quick Start

1. Initialize a schema in your project:

mdschema init

2. Validate your markdown files:

mdschema check README.md docs/*.md

3. Generate a template from your schema:

mdschema generate -o new-doc.md

Schema Format

Create a .mdschema.yml file to define your documentation structure:

structure:
  - heading: "# [a-zA-Z0-9_\\- ]+" # Regex pattern for project title
    children:
      - heading: "## Features"
        optional: true
      - heading: "## Installation"
        code_blocks:
          - { lang: bash, min: 1 } # Require at least 1 bash code block
        children:
          - heading: "### Windows"
            optional: true
          - heading: "### macOS"
            optional: true
      - heading: "## Usage"
        code_blocks:
          - { lang: go, min: 2 } # Require at least 2 Go code blocks
        required_text:
          - "example" # Must contain the word "example"
  - heading: "# LICENSE"
    optional: true

Schema Elements

• heading - Heading pattern (supports regex)
• optional - Whether the section is optional (default: false)
• children - Nested subsections that must appear within this section
• code_blocks - Code block requirements with language and count constraints
• required_text - Text that must appear within the section

Commands

check - Validate Documents

mdschema check README.md docs/**/*.md
mdschema check --schema custom.yml *.md

generate - Create Templates

# Generate from .mdschema.yml
mdschema generate
# Generate from specific schema file
mdschema generate --schema custom.yml
# Generate and save to file
mdschema generate -o template.md

init - Initialize Schema

# Create .mdschema.yml with defaults
mdschema init

Examples

Basic README Schema

structure:
  - heading: "# .*"
    children:
      - heading: "## Installation"
        code_blocks:
          - { lang: bash, min: 1 }
      - heading: "## Usage"
        code_blocks:
          - { lang: go, min: 1 }

API Documentation Schema

structure:
  - heading: "# API Reference"
    children:
      - heading: "## Authentication"
        required_text: ["API key", "Bearer token"]
      - heading: "## Endpoints"
        children:
          - heading: "### GET /users"
            code_blocks:
              - { lang: json, min: 1 }
              - { lang: curl, min: 1 }

Tutorial Schema

structure:
  - heading: "# *"
    children:
      - heading: "## Prerequisites"
      - heading: "## Step 1: *"
        code_blocks:
          - { min: 1 } # Any language
      - heading: "## Step 2: *"
        code_blocks:
          - { min: 1 }
      - heading: "## Next Steps"
        optional: true

Validation Rules

mdschema includes several built-in validation rules:

• Structure - Ensures sections appear in the correct order and hierarchy
• Required Text - Validates that required text appears in sections
• Code Blocks - Enforces code block requirements (language, minimum/maximum count)

Use Cases

• Documentation Standards - Enforce consistent README structure across repositories
• API Documentation - Ensure all endpoints have required sections and examples
• Tutorial Validation - Verify step-by-step guides follow the expected format
• CI/CD Integration - Validate documentation in pull requests
• Template Generation - Create starter templates for new projects

Development

Running Tests

go test ./...

Building

go build -o mdschema ./cmd/mdschema

Contributing

Contributions are welcome! Please feel free to submit a Pull Request. For major changes, please open an issue first to discuss what you would like to change. See CONTRIBUTING.md for more details.

License

MIT License - see LICENSE for details.