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-review2. 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 codebase3. Test it
crabtalk attach> /code-review
> Review the authentication moduleThe /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
| Field | Required | Description |
|---|---|---|
name | Yes | Skill identifier, used in /name commands |
description | Yes | One-line summary — affects BM25 search ranking |
allowed-tools | No | Space-separated tool names the skill pre-approves |
license | No | License reference |
compatibility | No | Requirements (e.g., "Requires git") |
metadata | No | Arbitrary 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
Skills are auto-discovered — not declared in manifests. Put your SKILL.md inside a skills/<name>/ directory in your package's source repository. When someone installs your package, CrabTalk finds the skill automatically.
my-repo/
skills/
code-review/
SKILL.mdCreate a hub manifest that points to your repo and open a pull request at github.com/crabtalk/hub. See the manifest spec for the full schema.