CrabTalkCrabTalk

Write a Skill

Create a custom skill — Markdown file, YAML frontmatter, available to all your agents.

A skill is a Markdown file with YAML frontmatter. Create one, drop it in the skills directory, and your agents can use it immediately.

1. Create the skill directory

mkdir -p ~/.crabtalk/skills/code-review

2. Write SKILL.md

Create ~/.crabtalk/skills/code-review/SKILL.md:

---
name: code-review
description: Review code for bugs, security issues, and style problems
allowed-tools: read_file search_files
---

You are a code reviewer. When asked to review code:

1. Read the files carefully
2. Check for bugs, security vulnerabilities, and style issues
3. Suggest specific improvements with code examples
4. Be concise — flag problems, don't rewrite the codebase

3. Test it

crabtalk attach
> /code-review
> Review the authentication module

The /code-review slash command loads the skill into the current session. The agent follows the skill's instructions for the rest of the conversation.

Frontmatter fields

FieldRequiredDescription
nameYesSkill identifier, used in /name commands
descriptionYesOne-line summary — affects BM25 search ranking
allowed-toolsNoSpace-separated tool names the skill pre-approves
licenseNoLicense reference
compatibilityNoRequirements (e.g., "Requires git")
metadataNoArbitrary key-value pairs

Writing good descriptions

The skill registry uses BM25 search over names and descriptions. A good description helps agents find skills automatically — not just through slash commands. Be specific: "Review code for bugs, security issues, and style problems" ranks better than "Code review skill."

Publishing to the hub

Add your skill to a hub package manifest to share it:

[skills.code-review]
description = "Review code for bugs, security issues, and style problems"
path = "skills/code-review"

See Hub for the full manifest format.

What's next

  • Skills — how skill discovery and scoping work
  • Hub — publish and share packages

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