mdlint

Lint markdown knowledge bases for consistency. Zero dependencies, pure Python.

Checks for broken links, missing frontmatter fields, orphaned files, duplicate titles, and empty files.

Usage

# Basic lint
python mdlint.py ./notes

# With frontmatter schema validation
python mdlint.py ./notes --schema type:str confidence:float last_updated:date

# Only show errors and warnings (skip info)
python mdlint.py ./notes --level warning

# JSON output
python mdlint.py ./notes --json

Checks

Code	Level	Description
E001	error	Cannot read file
E002	error	Frontmatter field has wrong type
E003	error	Broken internal link
W001	warning	Empty file
W002	warning	Missing required frontmatter field
W003	warning	Date field doesn't match YYYY-MM-DD
W004	warning	Duplicate title across files
I001	info	Orphaned file (nothing links to it)

Link formats

Detects both wikilinks and standard markdown links:

• [[filename]] and [[filename|display text]]
• [text](path.md)

Schema validation

Use --schema to require frontmatter fields:

mdlint ./notes --schema type:str confidence:float date:date

Types: str (any string), float (numeric), date (YYYY-MM-DD format).

License

MIT