frontmatterkit

A Unix-style CLI for validating, querying, asserting, and minimally updating front matter in Markdown files.

Features

• Validate YAML front matter for correctness
• Get front matter values by path, output as YAML or JSON
• Set front matter fields with minimal document changes
• Unset front matter fields cleanly
• Assert conditions on front matter for CI/CD checks
• Reads from --in or stdin and writes to --out or stdout
• Strict YAML validation with helpful exit codes

Installation

go install github.com/UnitVectorY-Labs/frontmatterkit@latest

Quick Usage

# Validate front matter
frontmatterkit validate --in post.md

# Get a field value
frontmatterkit get --path .title --in post.md

# Set a field
frontmatterkit set --set '.title=New Title' --in post.md --in-place

# Remove a field
frontmatterkit unset --path .draft --in post.md --in-place

# Assert conditions in CI
frontmatterkit assert --assert '.draft == false' --assert '.title exists' --in post.md

# Show command-specific help
frontmatterkit get help

License

This project is licensed under the MIT License.