Aigent Builder

AIgent Builder

Generates complete AI agent skill definitions from natural language purpose descriptions. Produces a valid SKILL.md file with YAML frontmatter and structured Markdown body following the Anthropic agent skill best practices.

When to Use

Use this skill when:

• The user asks to create, build, or generate a new agent skill
• The user describes functionality they want to package as a skill
• The user wants to scaffold a new SKILL.md file

Instructions

Step 1: Detect aigent availability

Run the following to check if the aigent CLI is installed:

command -v aigent

Step 2a: With aigent (primary mode)

If aigent is on PATH, use the CLI for authoritative skill generation:

1. Build the skill:

``bash aigent build "" --dir .claude/skills ``

Additional options:

• --name — override the derived skill name
• --license — set a license (e.g., MIT)
• --compatibility — set compatibility (e.g., claude)
• --allowed-tools — set allowed tools (e.g., Bash, Read, Write)
• --no-llm — force deterministic mode (no API key required)

If ANTHROPIC_API_KEY is set, aigent build uses Claude to generate richer names, descriptions, and body content. Without an API key, it falls back to deterministic generation automatically.

1. Validate the output:

``bash aigent validate .claude/skills/ ``

Exit code 0 means valid. Any errors are printed to stderr.

1. Report the output directory path and any warnings to the user.

Step 2b: Without aigent (fallback mode)

If aigent is not available, generate the skill manually using the Anthropic spec:

1. Derive a skill name from the user's purpose:

• Convert to kebab-case (lowercase, hyphens between words)
• Use gerund form for the verb (e.g., "process" becomes "processing")
• Maximum 64 characters
• Must not contain reserved words: anthropic, claude
• No leading, trailing, or consecutive hyphens

1. Write the SKILL.md with this structure:

```markdown --- name: description: . Use when . --- #

## When to Use

Use this skill when:

## Instructions

```

Rules for the description:

• Write in third person ("This skill processes..." not "Process...")
• Include a "Use when..." clause for auto-invocation triggers
• Maximum 1024 characters
• No XML-like tags (``)

1. Write to .claude/skills//SKILL.md using the Write tool (or a user-specified directory).

1. Inform the user that validation was not run because aigent is not installed. Recommend installing it for authoritative validation.

Output location

The default output directory is .claude/skills// (project-local skills). The user may specify an alternative directory. Both CLI mode and fallback mode use the same default.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: wkusnierczyk
• Source: wkusnierczyk/aigent-skills
• License: MIT

Install and usage instructions live in the source repository linked above.