Files
spec-kit/presets
Manfred Riem 497b5885e1 docs: Add Extensions & Presets section to README (#1898)
* docs: add Extensions & Presets section to README

Add a new 'Making Spec Kit Your Own: Extensions & Presets' section that covers:
- Layering diagram (Mermaid) showing resolution order
- Extensions: what they are, when to use, examples
- Presets: what they are, when to use, examples
- When-to-use-which comparison table
- Links to extensions/README.md and presets/README.md

* docs: clarify project-local overrides in layering diagram

Address review feedback: explain the project-local overrides layer
shown in the diagram, and adjust the intro to acknowledge it as a
third customization mechanism alongside extensions and presets.

* docs: Clarify template vs command resolution in README

- Separate template resolution (top-down, first-match-wins stack) from
  command registration (written directly into agent directories)
- Update Mermaid diagram paths to use <preset-id> and <ext-id>
  placeholders consistent with existing documentation

Addresses PR review feedback on #1898.

* docs: Clarify install-time vs runtime resolution for commands and templates

- README: label templates as runtime-resolved (stack walk) and commands
  as install-time (copied into agent directories, last-installed wins)
- presets/README: add runtime note to template resolution, contrast with
  install-time command registration

* docs: Address review — fix template copy wording, tighten command override description

- presets/README: clarify that preset files are copied at install but
  template resolution still walks the stack at runtime
- README: describe priority-based command resolution and automatic
  restoration on removal instead of vague 'replacing whatever was there'
2026-03-18 14:21:20 -05:00
..

Presets

Presets are stackable, priority-ordered collections of template and command overrides for Spec Kit. They let you customize both the artifacts produced by the Spec-Driven Development workflow (specs, plans, tasks, checklists, constitutions) and the commands that guide the LLM in creating them — without forking or modifying core files.

How It Works

When Spec Kit needs a template (e.g. spec-template), it walks a resolution stack:

  1. .specify/templates/overrides/ — project-local one-off overrides
  2. .specify/presets/<preset-id>/templates/ — installed presets (sorted by priority)
  3. .specify/extensions/<ext-id>/templates/ — extension-provided templates
  4. .specify/templates/ — core templates shipped with Spec Kit

If no preset is installed, core templates are used — exactly the same behavior as before presets existed.

Template resolution happens at runtime — although preset files are copied into .specify/presets/<id>/ during installation, Spec Kit walks the resolution stack on every template lookup rather than merging templates into a single location.

For detailed resolution and command registration flows, see ARCHITECTURE.md.

Command Overrides

Presets can also override the commands that guide the SDD workflow. Templates define what gets produced (specs, plans, constitutions); commands define how the LLM produces them (the step-by-step instructions).

Unlike templates, command overrides are applied at install time. When a preset includes type: "command" entries, the commands are registered into all detected agent directories (.claude/commands/, .gemini/commands/, etc.) in the correct format (Markdown or TOML with appropriate argument placeholders). When the preset is removed, the registered commands are cleaned up.

Quick Start

# Search available presets
specify preset search

# Install a preset from the catalog
specify preset add healthcare-compliance

# Install from a local directory (for development)
specify preset add --dev ./my-preset

# Install with a specific priority (lower = higher precedence)
specify preset add healthcare-compliance --priority 5

# List installed presets
specify preset list

# See which template a name resolves to
specify preset resolve spec-template

# Get detailed info about a preset
specify preset info healthcare-compliance

# Remove a preset
specify preset remove healthcare-compliance

Stacking Presets

Multiple presets can be installed simultaneously. The --priority flag controls which one wins when two presets provide the same template (lower number = higher precedence):

specify preset add enterprise-safe --priority 10      # base layer
specify preset add healthcare-compliance --priority 5  # overrides enterprise-safe
specify preset add pm-workflow --priority 1            # overrides everything

Presets override, they don't merge. If two presets both provide spec-template, the one with the lowest priority number wins entirely.

Catalog Management

Presets are discovered through catalogs. By default, Spec Kit uses the official and community catalogs:

# List active catalogs
specify preset catalog list

# Add a custom catalog
specify preset catalog add https://example.com/catalog.json --name my-org --install-allowed

# Remove a catalog
specify preset catalog remove my-org

Creating a Preset

See scaffold/ for a scaffold you can copy to create your own preset.

  1. Copy scaffold/ to a new directory
  2. Edit preset.yml with your preset's metadata
  3. Add or replace templates in templates/
  4. Test locally with specify preset add --dev .
  5. Verify with specify preset resolve spec-template

Environment Variables

Variable Description
SPECKIT_PRESET_CATALOG_URL Override the catalog URL (replaces all defaults)

Configuration Files

File Scope Description
.specify/preset-catalogs.yml Project Custom catalog stack for this project
~/.specify/preset-catalogs.yml User Custom catalog stack for all projects

Future Considerations

The following enhancements are under consideration for future releases:

  • Composition strategies — Allow presets to declare a strategy per template instead of the default replace:

    Type replace prepend append wrap
    template ✓ (default)
    command ✓ (default)
    script ✓ (default)

    For artifacts and commands (which are LLM directives), wrap would inject preset content before and after the core template using a {CORE_TEMPLATE} placeholder. For scripts, wrap would run custom logic before/after the core script via a $CORE_SCRIPT variable.

  • Script overrides — Enable presets to provide alternative versions of core scripts (e.g. create-new-feature.sh) for workflow customization. A strategy: "wrap" option could allow presets to run custom logic before/after the core script without fully replacing it.