* feat(presets): resolve constitutions at command time Gate install-time constitution materialization behind the constitution-sync preset while preserving one-time init seeding and authored-file safeguards. Assisted-by: GitHub Copilot (model: GPT-5.6 Sol, autonomous) Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Copilot-Session: 7dbce70f-80c6-4e14-a30d-78cb358bcb84 * fix(presets): emit composed template content Add a machine-readable preset resolve mode backed by PresetResolver.resolve_content and require the constitution command to consume it. Assisted-by: GitHub Copilot (model: GPT-5.6 Sol, autonomous) Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Copilot-Session: 7dbce70f-80c6-4e14-a30d-78cb358bcb84 * fix(presets): unify runtime template composition Assisted-by: GitHub Copilot (model: GPT-5.6 Sol, autonomous) Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Copilot-Session: 7dbce70f-80c6-4e14-a30d-78cb358bcb84 * fix(presets): secure runtime template resolution Align runtime resolution across script variants, validate registry path components, and honor canonical extension ordering and convention paths. Assisted-by: GitHub Copilot (model: GPT-5.6 Sol, autonomous) Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> * fix(presets): align runtime priority semantics Normalize and tie-break preset priorities consistently across script variants, and preserve template bytes when Python materializes generated files. Assisted-by: GitHub Copilot (model: GPT-5.6 Sol, autonomous) Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> * fix(presets): stop at effective template base Avoid parsing irrelevant lower layers once resolution reaches a replace base, and decode raw bytes so Python preserves source line endings. Assisted-by: GitHub Copilot (model: GPT-5.6 Sol, autonomous) Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> * fix(presets): align extension template resolution Support root-level extension templates across runtime resolvers, fail safely when Bash cannot parse an extension registry, and validate requested templates in every prerequisite output mode. Assisted-by: GitHub Copilot (model: GPT-5.6 Sol, autonomous) Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> * fix(presets): resolve dotted command identifiers Route safe dotted names through command resolution, correct traversal coverage, and make Windows CI text decoding explicit. Assisted-by: GitHub Copilot (model: GPT-5.6 Sol, autonomous) Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> * Avoid orphan feature directories on template errors Assisted-by: GitHub Copilot (model: GPT-5.6 Sol, autonomous) Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> * Align malformed preset manifest handling Assisted-by: GitHub Copilot (model: GPT-5.6 Sol, autonomous) Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Copilot-Session: 3158e06f-95df-4e3a-843f-f159a35aa30c * Complete runtime resolver parity Assisted-by: GitHub Copilot (model: GPT-5.6 Sol, autonomous) Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Copilot-Session: 3158e06f-95df-4e3a-843f-f159a35aa30c * Fail closed on resolver input errors Assisted-by: GitHub Copilot (model: GPT-5.6 Sol, autonomous) Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Copilot-Session: 3158e06f-95df-4e3a-843f-f159a35aa30c * Force UTF-8 and full manifest validation Force UTF-8 decoding for registry and manifest reads in the Bash and PowerShell embedded-Python parsers so resolution no longer depends on the process locale, and validate every manifest template entry's required fields, type, and strategy consistent with the canonical PresetManifest. Assisted-by: GitHub Copilot (model: claude-opus-4.8, autonomous) Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Copilot-Session: 3158e06f-95df-4e3a-843f-f159a35aa30c * Fail closed on empty manifests and corrupt registries Reject manifests missing the provides/templates sections or declaring an empty template list in all three runtime resolvers, matching the canonical PresetManifest which treats those as invalid instead of silently degrading a composing layer to a convention `replace` lookup. Make a corrupt or unreadable extension registry fail closed in Bash, PowerShell, and Python instead of swallowing the error and treating every on-disk extension directory as unregistered-and-enabled, which could activate a disabled extension. Read the preset and extension registries as explicit UTF-8 in the PowerShell resolver so priority/enabled-state decoding no longer depends on the process code page under Windows PowerShell 5.1. Assisted-by: GitHub Copilot (model: claude-opus-4.8, autonomous) Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Copilot-Session: 3158e06f-95df-4e3a-843f-f159a35aa30c * fix(presets): fail closed when extension registry is not a regular file The Bash and Python resolvers used is_file()/`-f` to gate reading the extension `.registry`, which returns false for a directory or a broken symlink at that path. In those cases the resolvers treated the registry as absent and scanned every on-disk extension directory as unregistered and enabled — a fail-open path. Detect any filesystem entry at the registry path (including broken symlinks) and reject unless it is a readable regular file. PowerShell now rejects a non-leaf entry explicitly for parity. Adds directory- and broken-symlink parity regressions. Assisted-by: GitHub Copilot (model: claude-opus-4.8, autonomous) Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Copilot-Session: 3158e06f-95df-4e3a-843f-f159a35aa30c * fix(presets): fail closed on corrupt registry in canonical resolver and PowerShell Two remaining fail-open paths for an invalid extension registry: - The canonical PresetResolver enumerated extensions through ExtensionRegistry, whose _load() normalizes a corrupt or unreadable registry to an empty mapping. The directory scan then admitted every on-disk extension directory as unregistered-and-enabled, so a corrupt registry could still supply constitution content at init and through constitution-sync materialization. Add a non-invasive is_corrupt() probe (recovery behavior for install/enable/disable is unchanged) and raise from _get_all_extensions_by_priority() when the registry exists but is invalid. _load() now also recovers from OSError/UnicodeDecodeError so a directory or unreadable registry no longer crashes construction. - The PowerShell resolver gated the registry read with Test-Path, which returns false for a dangling symlink on Windows, letting a broken .registry symlink bypass the guard and enable every on-disk extension. Detect the entry via directory enumeration (which observes a broken symlink) and reject it unless it is a readable regular file. Adds canonical corrupt/directory-registry regressions and extends the broken-symlink parity test to PowerShell. Assisted-by: GitHub Copilot (model: claude-opus-4.8, autonomous) Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Copilot-Session: 3158e06f-95df-4e3a-843f-f159a35aa30c * fix(presets): detect dangling registry symlink in ExtensionRegistry.is_corrupt is_corrupt() gated on Path.exists(), which follows symlinks and returns False for a dangling .registry symlink — so the canonical PresetResolver treated it as an absent registry and fell back to scanning every on-disk extension directory as unregistered-and-enabled, reopening the fail-open path this guard closes. Detect lexical existence with os.path.lexists and require a regular file before parsing, so a broken symlink (or directory) is reported corrupt and resolution fails closed. Adds a canonical broken-symlink regression alongside the directory case. Assisted-by: GitHub Copilot (model: claude-opus-4.8, autonomous) Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Copilot-Session: 3158e06f-95df-4e3a-843f-f159a35aa30c --------- Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Copilot-Session: 7dbce70f-80c6-4e14-a30d-78cb358bcb84 Copilot-Session: 3158e06f-95df-4e3a-843f-f159a35aa30c
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:
.specify/templates/overrides/— project-local one-off overrides.specify/presets/<preset-id>/templates/— installed presets (sorted by priority).specify/extensions/<ext-id>/templates/— extension-provided templates.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.
constitution-template follows the same runtime model. Project initialization seeds
.specify/memory/constitution.md once so downstream commands always have a constitution to read.
After that, installing, removing, enabling, disabling, or reprioritizing presets does not rewrite the
live constitution. Each /constitution run resolves the current composed constitution-template,
then applies existing project values and amendments to that scaffold.
Teams that intentionally want preset stack changes to refresh an unchanged generated constitution can
install the bundled constitution-sync preset. It restores guarded install-time materialization in
addition to its command-time propagation behavior; authored constitutions remain protected.
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 by default, they don't merge. If two presets both provide spec-template with the default replace strategy, the one with the lowest priority number wins entirely. However, presets can use composition strategies to augment rather than replace content.
Composition Strategies
Presets can declare a strategy per template to control how content is combined. The name field identifies which template to compose with in the priority stack, while file points to the actual content file (which can differ from the convention path templates/<name>.md):
provides:
templates:
- type: "template"
name: "spec-template"
file: "templates/spec-addendum.md"
strategy: "append" # adds content after the core template
| Strategy | Description |
|---|---|
replace (default) |
Fully replaces the lower-priority template |
prepend |
Places content before the resolved lower-priority template, separated by a blank line |
append |
Places content after the resolved lower-priority template, separated by a blank line |
wrap |
Content contains {CORE_TEMPLATE} placeholder (or $CORE_SCRIPT for scripts) replaced with the lower-priority content |
Supported combinations:
| Type | replace |
prepend |
append |
wrap |
|---|---|---|---|---|
| template | ✓ (default) | ✓ | ✓ | ✓ |
| command | ✓ (default) | ✓ | ✓ | ✓ |
| script | ✓ (default) | — | — | ✓ |
Multiple composing presets chain recursively. For example, a security preset with prepend and a compliance preset with append will produce: security header + core content + compliance footer.
Catalog Management
Presets are discovered through catalogs. By default, Spec Kit uses the official and community catalogs:
Note
Community presets 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 preset code itself. Review preset source code before installation and use at your own discretion.
# 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.
- Copy
scaffold/to a new directory - Edit
preset.ymlwith your preset's metadata - Add or replace templates in
templates/ - Test locally with
specify preset add --dev . - Verify with
specify preset resolve spec-template
Environment Variables
| Variable | Description | Default |
|---|---|---|
SPECKIT_PRESET_CATALOG_URL |
Override the full catalog stack with a single URL (replaces all defaults) | Built-in default stack |
GH_TOKEN / GITHUB_TOKEN |
GitHub token for authenticated requests to GitHub-hosted URLs (raw.githubusercontent.com, github.com, api.github.com, codeload.github.com). Required when your catalog JSON or preset ZIPs are hosted in a private GitHub repository. |
None |
Example: Using a private GitHub-hosted catalog
# Authenticate with a token (gh CLI, PAT, or GITHUB_TOKEN in CI)
export GITHUB_TOKEN=$(gh auth token)
# Search a private catalog added via `specify preset catalog add`
specify preset search my-template
# Install from a private catalog
specify preset add my-template
The token is attached automatically to requests targeting GitHub domains. Non-GitHub catalog URLs are always fetched without credentials.
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:
- Structural merge strategies — Parsing Markdown sections for per-section granularity (e.g., "replace only ## Security").
- Conflict detection —
specify preset lint/specify preset doctorfor detecting composition conflicts.