Files
github-spec-kit/presets/README.md
Copilot a067d4c2e3 feat(presets): Composition strategies (prepend, append, wrap) for templates, commands, and scripts (#2133)
* fix: rebase onto upstream/main, resolve conflicts with PR #2189

upstream/main merged PR #2189 (wrap-only strategy) which overlaps with
our comprehensive composition strategies (prepend/append/wrap). Resolved
conflicts keeping our implementation as source of truth:

- README: keep our future considerations (composition is now fully
  implemented, not a future item)
- presets.py: keep our composition architecture (_reconcile_composed_commands,
  collect_all_layers, resolve_content) while preserving #2189's
  _substitute_core_template which is used by agents.py for skill
  generation
- tests: keep both test sets (our composition tests + #2189's wrap
  tests), removed TestReplayWrapsForCommand and
  TestInstallRemoveWrapLifecycle which test the superseded
  _replay_wraps_for_command API; our composition tests cover equivalent
  scenarios
- Restored missing _unregister_commands call in remove() that was lost
  during #2189 merge

* fix: re-create skill directory in _reconcile_skills after removal

After _unregister_skills removes a skill directory, _register_skills
skips writing because the dir no longer passes the is_dir() check.
Fix by ensuring the skill subdirectory exists before calling
_register_skills so the next winning preset's content gets registered.

Fixes the Claude E2E failure where removing a top-priority override
preset left skill-based agents without any SKILL.md file.

* fix: address twenty-third round of Copilot PR review feedback

- Protect reconciliation in remove(): wrap _reconcile_composed_commands
  and _reconcile_skills in try/except so failures emit a warning instead
  of leaving the project in an inconsistent state
- Protect reconciliation in install(): same pattern for post-install
  reconciliation so partial installs don't lack cleanup
- Inherit scripts/agent_scripts from base frontmatter: when composing
  commands, merge scripts and agent_scripts keys from the base command's
  frontmatter into the top layer's frontmatter if missing, preventing
  composed commands from losing required script references
- Add tier-5 bundled core fallback to collect_all_layers(): check the
  bundled core_pack (wheel) or repo-root templates (source checkout) when
  .specify/templates/ doesn't contain the core file, matching resolve()'s
  tier-5 fallback so composition can always find a base layer

* fix: address twenty-fourth round of Copilot PR review feedback

- Use yaml.safe_load for frontmatter parsing in resolve_content instead
  of CommandRegistrar.parse_frontmatter which uses naive find('---',3);
  strip strategy key from final frontmatter to prevent leaking internal
  composition directives into rendered agent command files
- Filter _reconcile_skills to specific commands: use _FilteredManifest
  wrapper so only the commands being reconciled get their skills updated,
  preventing accidental overwrites of other commands' skills that may be
  owned by higher-priority presets

* fix: address twenty-fifth round of Copilot PR review feedback

- Support legacy command-frontmatter strategy: when preset.yml doesn't
  declare a strategy, check the command file's YAML frontmatter for
  strategy: wrap as a fallback so legacy wrap presets participate in
  composition and multi-preset chaining
- Guard skill dir creation in _reconcile_skills: only re-create the
  skill directory if the skill was previously managed (listed in some
  preset's registered_skills), avoiding creation of new skill dirs
  that _register_skills would normally skip

* fix: add explanatory comment to empty except in legacy frontmatter parsing

* fix: address twenty-sixth round of Copilot PR review feedback

- Unregister stale commands when composition fails: when resolve_content
  returns None during reconciliation (base layer removed), unregister
  the command from non-skill agents and emit a warning
- Load extension aliases during reconciliation: _register_command_from_path
  now checks extension.yml for aliases when the winning layer is an
  extension, so alias files are restored after preset removal
- Use line-based fence detection for legacy frontmatter strategy fallback:
  scan for --- on its own line instead of split('---',2) to avoid
  mis-parsing YAML values containing ---

* fix: address twenty-seventh round of Copilot PR review feedback

- Handle non-preset winners in _reconcile_skills: when the winning
  layer is core/extension/project-override, restore skills via
  _unregister_skills so skill-based agents stay consistent with the
  priority stack
- Update base_frontmatter_text on replace layers: when a higher-priority
  replace layer occurs during composition, update both top and base
  frontmatter so scripts/agent_scripts inheritance reflects the
  effective base beneath the top composed layer

* fix: address twenty-eighth round of Copilot PR review feedback

- Parse only interior lines in _parse_fm_yaml: use lines[1:-1] instead
  of filtering all --- lines, preventing corruption when YAML values
  contain a line that is exactly ---
- Omit empty frontmatter: skip re-rendering when top_fm is empty dict
  to avoid emitting ---/{}/--- for intentionally empty frontmatter
- Update scaffold wrap comment: mention both {CORE_TEMPLATE} and
  $CORE_SCRIPT placeholders for templates/commands vs scripts
- Clarify shell composition scope in ARCHITECTURE.md: note that bash/PS1
  resolve_template_content only handles templates; command/script
  composition is handled by the Python resolver

* fix: address twenty-ninth round of Copilot PR review feedback

- Fix TestCollectAllLayers docstring: reference collect_all_layers()
- Add default/unknown strategy handling in bash/PS1 composition: error
  on unrecognized strategy values instead of silently skipping
- Fix comment: .composed/ is a persistent dir, not temporary
- Fix comment: legacy fallback checks all valid strategies, not just wrap
- Cache PresetRegistry in _reconcile_skills: build presets_by_priority
  once instead of constructing registry per-command

* fix: address thirtieth round of Copilot PR review feedback

- Guard legacy frontmatter fallback: only check command file frontmatter
  for strategy when the manifest entry doesn't explicitly include the
  strategy key, preventing override of manifest-declared strategies
- Document rollback limitation: note that mid-registration failures may
  leave orphaned agent command files since partial progress isn't
  captured by the local vars

* fix: handle project override skills and extension context in reconciliation

* fix: add comment to empty except in extension registration fallback

* fix: filter extension commands in reconciliation and fix type annotation

* fix: filter extension commands from post-install reconciliation

Apply the same extension-installed check used in _register_commands to
the reconciliation command list, preventing reconciliation from
registering commands for extensions that are not installed.

* fix: skip convention fallback for explicit file paths and add stem fallback to tier-5

When a preset manifest provides an explicit file path that does not
exist, skip the convention-based fallback to avoid masking typos.
Also add speckit.<stem> to <stem>.md fallback in tier-5 bundled/source
core lookup for consistency with tier-4.

* fix: scan past non-replace layers to find base in resolve_content

The base-finding scan now skips non-replace layers below a replace
layer instead of stopping at the first non-replace. This fixes the
case where a low-priority append/prepend layer sits below a replace
that should serve as the base for composition.

* fix: add context_note to non-skill agent registration for extensions

Add context_note parameter to register_commands_for_non_skill_agents
and pass extension name/id during reconciliation so rendered command
files preserve the extension-specific context markers.

* fix: Optional type, rollback safety, and override skill restoration

- Fix context_note type to Optional[str]
- Wrap shutil.rmtree in try/except during install rollback
- Separate override-backed skills from core/extension in _reconcile_skills

* fix: align bash/PS1 base-finding with Python resolver

Rewrite bash and PowerShell composition loops to find the effective
base replace layer first (scanning bottom-up, skipping non-replace
layers below it), then compose only from the base upward. This
prevents evaluation of irrelevant lower layers (e.g. a wrap with
no placeholder below a replace) and matches resolve_content behavior.

* fix: PS1 no-python warning, integration hook for override skills, alias cleanup

- Warn when no Python 3 found in PS1 and presets use composition strategies
- Apply post_process_skill_content integration hook when restoring
  override-backed skills so agent-specific flags are preserved
- Unregister command aliases alongside primary name when composition
  fails to prevent orphaned alias files

* fix: include aliases in removed_cmd_names during preset removal

Read aliases from preset manifest before deleting pack_dir so alias
command files are included in unregistration and reconciliation.

* fix: add comment to empty except in alias extraction during removal

* fix: scan top-down for effective base in all resolvers

Change base-finding to scan from highest priority downward to find the
nearest replace layer, then compose only layers above it. Prevents
evaluation of irrelevant lower layers (e.g. a wrap without placeholder
below a higher-priority replace) across Python, bash, and PowerShell.

* fix: align CLI composition chain display with top-down base-finding

Show only contributing layers (base and above) in preset resolve
output, matching resolve_content top-down semantics. Layers below
the effective base are omitted since they do not contribute.

* fix: guard corrupted registry entries and make manifest authoritative

- Add isinstance(meta, dict) guard in bash registry parsing so corrupted
  entries are skipped instead of breaking priority ordering
- Only use convention-based file lookup when the manifest does not list
  the requested template, making preset.yml authoritative and preventing
  stray on-disk files from creating unintended layers

* fix: align resolve() with manifest file paths and match extension context_note

- Update resolve() preset tier to consult manifest file paths before
  convention-based lookup, matching collect_all_layers behavior
- Use exact extension context_note format matching extensions.CommandRegistrar
- Update test to declare template in manifest (authoritative manifest)

* revert: restore resolve() convention-based behavior for backwards compatibility

resolve() is the existing public API used by shell scripts and other
callers. Changing it to manifest-authoritative breaks backward compat
for presets that rely on convention-based file lookup. Only the new
collect_all_layers/resolve_content path uses manifest-authoritative
logic.

* fix: only pre-compose when this preset is the top composing layer

Skip composition in _register_commands when a higher-priority replace
layer already wins for the command. Register the raw file instead and
let reconciliation write the correct final content.

* fix: deduplicate PyYAML warnings and use self.registry in reconciliation

- Emit PyYAML-missing warning once per function call in bash/PS1 instead
  of per-preset to avoid spamming stderr
- Use self.registry.list_by_priority() in reconciliation methods instead
  of constructing new PresetRegistry instances to avoid redundant I/O
  and potential consistency issues

* fix: document strategy handling consistency between layers and registrar

Composed output already strips strategy from frontmatter (resolve_content
pops it). Raw file registration preserves legacy frontmatter strategy
for backward compat; reconciliation corrects the final state.

* fix: correct stale comments for alias tracking and base-finding algorithm

* security: validate manifest file paths in bash/PowerShell resolvers

Reject absolute paths and parent directory traversal (..) in the
manifest-declared file field before joining with the preset directory.
Matches the Python-side validation in PresetManifest._validate().

---------

Co-authored-by: Manfred Riem <15701806+mnriem@users.noreply.github.com>
2026-04-23 10:07:52 -05:00

6.4 KiB

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 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. GitHub and the Spec Kit maintainers may review pull requests that add entries to the community catalog for formatting, catalog structure, or policy compliance, but 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.

  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:

  • Structural merge strategies — Parsing Markdown sections for per-section granularity (e.g., "replace only ## Security").
  • Conflict detectionspecify preset lint / specify preset doctor for detecting composition conflicts.