Extensify

A Spec Kit extension for creating and validating extensions and extension catalogs.

Overview

Extensify provides tooling for extension authors — scaffolding new extensions, validating them before publishing, and managing self-hosted extension catalogs.

Installation

specify extension add extensify

Commands

Command	Purpose
/speckit.extensify.create-extension	Scaffold a new extension from scratch
/speckit.extensify.validate-extension	Validate an extension directory for correctness
/speckit.extensify.create-catalog	Create a catalog.json for a self-hosted extension catalog
/speckit.extensify.validate-catalog	Validate an extension catalog.json for schema correctness
/speckit.extensify.create-extension-from-skill	Create a Spec Kit extension from a skill (SKILL.md)

Usage

Creating a New Extension

/speckit.extensify.create-extension my-tool

The command will:

1. Ask for extension metadata (name, description, author, etc.)
2. Ask what commands the extension should provide
3. Generate the full extension scaffold with extension.yml, command stubs, README, CHANGELOG, and LICENSE

Validating an Extension

Before publishing, validate the extension directory:

/speckit.extensify.validate-extension ./my-tool

Checks extension.yml schema, command name patterns, referenced files exist, unreferenced files, hooks, and recommended supporting files.

Creating a Self-Hosted Catalog

If you maintain multiple extensions and want to make them discoverable via specify extension search:

/speckit.extensify.create-catalog

The command will:

1. Ask for the URL where you'll host the catalog
2. Optionally scan extension directories to auto-populate entries from their extension.yml manifests
3. Generate a valid catalog.json
4. Show how to register the catalog with specify extension catalog add

Validating a Catalog

/speckit.extensify.validate-catalog ./catalog.json

Checks JSON syntax, schema conformance, semver format, alphabetical ordering, ID consistency, and required fields.

Creating an Extension from a Skill

Skills (SKILL.md) are great for packaging procedural knowledge, but they live inside a single project or user profile. Converting a skill into a Spec Kit extension makes it:

• Shareable — publish to a catalog so others can install it with specify extension add
• Versioned — track changes with semver and a changelog
• Discoverable — listed in specify extension search across teams and organizations
• Portable — works in any project without copying files manually
• Composable — presets can customize the extension's templates and commands using composition strategies (replace, prepend, append, wrap)

If you have an existing agent skill (a directory with a SKILL.md), convert it into a Spec Kit extension:

/speckit.extensify.create-extension-from-skill ./path/to/skill-dir

The command will:

1. Read the SKILL.md frontmatter and body
2. Ask for additional metadata (author, repository, etc.)
3. Generate a full extension scaffold with the skill's procedure as the main command
4. Copy any bundled resources (scripts, references, assets) into a resources/ directory