Spec Kit Extensions

Extension system for Spec Kit - add new functionality without bloating the core framework.

Extension Catalogs

Spec Kit provides two catalog files with different purposes:

Your Catalog (catalog.json)

• Purpose: Default upstream catalog of extensions used by the Spec Kit CLI
• Default State: Empty by design in the upstream project - you or your organization populate a fork/copy with extensions you trust
• Location (upstream): extensions/catalog.json in the GitHub-hosted spec-kit repo
• CLI Default: The specify extension commands use the upstream catalog URL by default, unless overridden
• Org Catalog: Point SPECKIT_CATALOG_URL at your organization's fork or hosted catalog JSON to use it instead of the upstream default
• Customization: Copy entries from the community catalog into your org catalog, or add your own extensions directly

Example override:

# Override the default upstream catalog with your organization's catalog
export SPECKIT_CATALOG_URL="https://your-org.com/spec-kit/catalog.json"
specify extension search  # Now uses your organization's catalog instead of the upstream default

Community Reference Catalog (catalog.community.json)

NOTE

Community extensions are independently created and maintained by their respective authors. Maintainers only verify that catalog entries are complete and correctly formatted — they do not review, audit, endorse, or support the extension code itself. Review extension source code before installation and use at your own discretion.

• Purpose: Browse available community-contributed extensions
• Status: Active - contains extensions submitted by the community
• Location: extensions/catalog.community.json
• Usage: Reference catalog for discovering available extensions
• Submission: Open to community contributions via issue template

How It Works:

Making Extensions Available

You control which extensions your team can discover and install:

Option 1: Curated Catalog (Recommended for Organizations)

Populate your catalog.json with approved extensions:

1. Discover extensions from various sources:
   • Browse catalog.community.json for community extensions
   • Find private/internal extensions in your organization's repos
   • Discover extensions from trusted third parties
2. Review extensions and choose which ones you want to make available
3. Add those extension entries to your own catalog.json
4. Team members can now discover and install them:
   • specify extension search shows your curated catalog
   • specify extension add <name> installs from your catalog

Benefits: Full control over available extensions, team consistency, organizational approval workflow

Example: Copy an entry from catalog.community.json to your catalog.json, then your team can discover and install it by name.

Option 2: Direct URLs (For Ad-hoc Use)

Skip catalog curation - team members install directly using URLs: