Skill Builder

Building an Opencode Skill

Agent skills let OpenCode discover reusable instructions from your repository or home directory. Skills are loaded on-demand via the native skill tool—agents see available skills and can load the full content when needed.

🛠️ 1. Skill File Placement

For a global skill, place the SKILL.md file in: ~/.config/opencode/skills/<skill-name>/SKILL.md

🔍 2. Understanding Discovery

OpenCode searches several locations for skills:

• Project config: .opencode/skills/<name>/SKILL.md
• Global config: ~/.config/opencode/skills/<name>/SKILL.md (This is where we are placing it)
• ... and others (e.g., .claude/skills, .agents/skills).

✍️ 3. Writing the SKILL.md

Each SKILL.md must start with YAML frontmatter. Only these fields are recognized:

• name (required): The skill's unique, lowercase, alphanumeric name.
• description (required): A concise explanation (1-1024 characters).
• license (optional): The license of the skill.
• compatibility (optional): The compatibility scope (e.g., opencod).
• metadata (optional, string-to-string map): Additional configuration data.

Validation Rules:

• name must be 1–64 characters.
• name must be lowercase alphanumeric with single hyphen separators.
• name must not start or end with -, nor contain consecutive --.

📄 4. Content Structure

The skill definition should include:

What I do

A bulleted list describing the specific actions and functionalities the skill provides (e.g., "Draft release notes," "Propose a version bump").

When to use me

A clear, actionable guide on the conditions under which an agent should invoke this skill (e.g., "Use this when you are preparing a tagged release.").

⚙️ 5. Advanced Configuration

You can control skill access using permissions in opencode.json:

• allow: Skill loads immediately.
• deny: Skill is hidden from the agent.
• ask: User is prompted for approval before loading.

Permissions support wildcards (e.g., internal-*).

🚀 Example of a Complete Skill

---
name: git-release
description: Create consistent releases and changelogs
license: MIT
compatibility: opencode
metadata:
  audience: maintainers
  workflow: github
---

## What I do

- Draft release notes from merged PRs
- Propose a version bump
- Provide a copy-pasteable `gh release create` command

## When to use me

Use this when you are preparing a tagged release. Ask clarifying questions if the target versioning scheme is unclear.

Source: jeremyckahn/dotfiles — distributed by TomeVault.