Extensions

Extensions add new capabilities to Spec Kit — domain-specific commands, external tool integrations, quality gates, and more. They introduce new commands and templates that go beyond the built-in Spec-Driven Development workflow.

Search Available Extensions

specify extension search [query]
Option Description
--tag Filter by tag
--author Filter by author
--verified Show only verified extensions

Searches all active catalogs for extensions matching the query. Without a query, lists all available extensions.

Install an Extension

specify extension add <name>
Option Description
--dev Install from a local directory (for development)
--from <url> Install from a custom URL instead of the catalog
--priority <N> Resolution priority (default: 10; lower = higher precedence)

Installs an extension from the catalog, a URL, or a local directory. Extension commands are automatically registered with the currently installed AI coding agent integration.

Note: All extension commands require a project already initialized with specify init.

Remove an Extension

specify extension remove <name>
Option Description
--keep-config Preserve configuration files during removal
--force Skip confirmation prompt

Removes an installed extension. Configuration files are backed up by default; use --keep-config to leave them in place or --force to skip the confirmation.

List Installed Extensions

specify extension list
Option Description
--available Show available (uninstalled) extensions
--all Show both installed and available extensions

Lists installed extensions with their status, version, and command counts.

Extension Info

specify extension info <name>

Shows detailed information about an installed or available extension, including its description, version, commands, and configuration.

Update Extensions

specify extension update [<name>]

Updates a specific extension, or all installed extensions if no name is given.

Enable / Disable an Extension

specify extension enable <name>
specify extension disable <name>

Disable an extension without removing it. Disabled extensions are not loaded and their commands are not available. Re-enable with enable.

Set Extension Priority

specify extension set-priority <name> <priority>

Changes the resolution priority of an extension. When multiple extensions provide a command with the same name, the extension with the lowest priority number takes precedence.

Catalog Management

Extension catalogs control where search and add look for extensions. Catalogs are checked in priority order (lower number = higher precedence).

List Catalogs

specify extension catalog list

Shows all active catalogs in the stack with their priorities and install permissions.

Add a Catalog

specify extension catalog add <url>
Option Description
--name <name> Required. Unique name for the catalog
--priority <N> Priority (default: 10; lower = higher precedence)
--install-allowed / --no-install-allowed Whether extensions can be installed from this catalog
--description <text> Optional description

Adds a catalog to the project's .specify/extension-catalogs.yml.

Remove a Catalog

specify extension catalog remove <name>

Removes a catalog from the project configuration.

Catalog Resolution Order

Catalogs are resolved in this order (first match wins):

  1. Environment variable — SPECKIT_CATALOG_URL overrides all catalogs
  2. Project config — .specify/extension-catalogs.yml
  3. User config — ~/.specify/extension-catalogs.yml
  4. Built-in defaults — official catalog + community catalog

Example .specify/extension-catalogs.yml:

catalogs:
  - name: "my-org-catalog"
    url: "https://example.com/catalog.json"
    priority: 5
    install_allowed: true
    description: "Our approved extensions"

Extension Configuration

Most extensions include configuration files in their install directory:

.specify/extensions/<ext>/
├── <ext>-config.yml           # Project config (version controlled)
├── <ext>-config.local.yml     # Local overrides (gitignored)
└── <ext>-config.template.yml  # Template reference

Configuration is merged in this order (highest priority last):

  1. Extension defaults (from extension.yml)
  2. Project config (<ext>-config.yml)
  3. Local overrides (<ext>-config.local.yml)
  4. Environment variables (SPECKIT_<EXT>_*)

To set up configuration for a newly installed extension, copy the template:

cp .specify/extensions/<ext>/<ext>-config.template.yml \
   .specify/extensions/<ext>/<ext>-config.yml

FAQ

Check the spelling of the extension name. The extension may not be published yet, or it may be in a catalog you haven't added. Use specify extension catalog list to see which catalogs are active.

Why doesn't the extension command appear in my AI coding agent?

Verify the extension is installed and enabled with specify extension list. If it shows as installed, restart your AI coding agent — it may need to reload for it to take effect.

How do I set up extension configuration?

Copy the config template that ships with the extension:

cp .specify/extensions/<ext>/<ext>-config.template.yml \
   .specify/extensions/<ext>/<ext>-config.yml

See Extension Configuration for details on config layers and overrides.

How do I resolve an incompatible version error?

Update Spec Kit to the version required by the extension.

Who maintains extensions?

Most extensions are independently created and maintained by their respective authors. The Spec Kit maintainers do not review, audit, endorse, or support extension code. Review an extension's source code before installing and use at your own discretion. For issues with a specific extension, contact its author or file an issue on the extension's repository.

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