class Riffer::Skills::Frontmatter

Immutable value object holding parsed SKILL.md YAML frontmatter.

Required fields per the Agent Skills spec: name and description. All unrecognized top-level frontmatter keys are merged into metadata.

frontmatter, body = Riffer::Skills::Frontmatter.parse(raw_content)

Constants

MAX_DESCRIPTION_LENGTH
MAX_NAME_LENGTH
NAME_PATTERN

Attributes

description [R]

The skill description (1-1024 chars).

metadata [R]

Arbitrary key-value metadata from the spec’s metadata field and any unrecognized top-level frontmatter keys.

name [R]

The skill name (1-64 chars, lowercase alphanumeric and hyphens).

Public Class Methods

new (name:, description:, metadata: {})

Source

# File lib/riffer/skills/frontmatter.rb, line 81
def initialize(name:, description:, metadata: {})
  validate_name!(name)
  validate_description!(description)
  @name = name.freeze
  @description = description.freeze
  @metadata = metadata.freeze
end

Creates a new Frontmatter.

name: the skill name (must match +[a-z0-9]([a-z0-9-]*[a-z0-9])?+, 1-64 chars).
description: the skill description (1-1024 chars).
metadata: optional metadata hash.

Raises Riffer::ArgumentError if name or description is invalid.

parse (raw)

Source

# File lib/riffer/skills/frontmatter.rb, line 38
def self.parse(raw)
  yaml, body = split_frontmatter(raw)
  raise Riffer::ArgumentError, "missing YAML frontmatter (expected --- delimiters)" if yaml.empty?
  [new(name: yaml.delete(:name), description: yaml.delete(:description), metadata: yaml), body]
end

Parses a raw SKILL.md string into a Frontmatter and body.

Splits on YAML front matter delimiters (---). Unrecognized top-level keys become metadata. Available to custom backends so they don’t need to reimplement parsing.

Raises Riffer::ArgumentError if frontmatter is invalid.

parse_frontmatter (raw)

Source

# File lib/riffer/skills/frontmatter.rb, line 50
def self.parse_frontmatter(raw)
  yaml, _ = split_frontmatter(raw)
  raise Riffer::ArgumentError, "missing YAML frontmatter (expected --- delimiters)" if yaml.empty?
  new(name: yaml.delete(:name), description: yaml.delete(:description), metadata: yaml)
end

Parses only the frontmatter from a raw SKILL.md string, ignoring the body.

Raises Riffer::ArgumentError if frontmatter is invalid.