Skills

Source: ./src/skills/

A skill is a markdown document with YAML frontmatter describing a reusable procedure — "how to write a changelog entry", "how to convert a fixture to a factory", etc. Agents discover skills via the skill_tool and load them on demand.

Skill format

---
name: write-changelog
description: Compose a user-facing changelog entry from a merged PR.
trigger_patterns:
  - "PR merged to main"
---

# Write changelog

1. Read `CHANGELOG.md`.
2. Determine the unreleased section...

Loading

• Bundled skills — shipped in ./src/skills/bundled/ and loaded by loadBundledSkills().
• User skills — placed under ./memory/skills/*.md (or <workspace>/skills/*.md) and loaded by the file-based loader.

Registry

import { SkillRegistry, loadBundledSkills } from 'guildhall/skills'

const registry = new SkillRegistry()
registry.registerAll(await loadBundledSkills())

Registries are keyed by name (from frontmatter) so later registrations can override earlier ones.

Invoking from an agent

The agent calls skill_tool.list() to see what's available and skill_tool.invoke(name, args) to append the skill content to its context. Invocation is recorded in tool_metadata.invoked_skills so the same skill isn't re-loaded every turn.