pig/skill

Skill loading and parsing.

A Skill is a directory on disk containing a SKILL.md file with YAML frontmatter (name + description) and a markdown body.

Frontmatter parsing is deliberately simple: split on --- delimiters, extract name and description fields from the YAML-like block. No full YAML parser needed.

Types

Frontmatter

</>

Parsed frontmatter fields and remaining body.

pub type Frontmatter {
  Frontmatter(name: String, description: String, body: String)
}

Constructors

Frontmatter(name: String, description: String, body: String)

Skill

</>

A loaded skill with its metadata.

pub type Skill {
  Skill(
    name: String,
    description: String,
    path: String,
    files: List(String),
  )
}

Constructors

Skill(
  name: String,
  description: String,
  path: String,
  files: List(String),
)

SkillError

</>

Errors that can occur during skill loading.

pub type SkillError {
  SkillNotFound
  InvalidFrontmatter
}

Constructors

```
SkillNotFound
```
```
InvalidFrontmatter
```

Values

load

</>

pub fn load(path: String) -> Result(Skill, SkillError)

Load a skill from a directory path.

Reads SKILL.md from the directory, parses frontmatter for name/description, and lists supplementary files (everything except SKILL.md).

parse_frontmatter

</>

pub fn parse_frontmatter(
  raw: String,
) -> Result(Frontmatter, SkillError)

Parse frontmatter from a SKILL.md content string.

Expects ---\n at start, content between delimiters, and closing ---\n. Extracts name: and description: fields. Returns remaining body after the closing delimiter.

This is a simple parser — not a full YAML parser. It handles:

key: value lines

skill_to_system_fragment

</>

pub fn skill_to_system_fragment(skill: Skill) -> String

Generate a system prompt fragment from a skill.

Used to inject skill descriptions into the system prompt so the agent knows what skills are available.