feat: add bundled lean preset with minimal workflow commands

Add a lean preset that overrides the 5 core workflow commands (specify,
plan, tasks, implement, constitution) with minimal prompts that produce
exactly one artifact each — no extension hooks, no scripts, no git
branching, no templates.

Bundled preset infrastructure:
- Add _locate_bundled_preset() mirroring _locate_bundled_extension()
- Update 'specify init --preset' to try bundled -> catalog fallback
- Update 'specify preset add' to try bundled -> catalog fallback
- Add bundled guard in download_pack() for presets without download URLs
- Add lean to presets/catalog.json with 'bundled: true' marker
- Add lean to pyproject.toml force-include for wheel packaging
- Align error messages with bundled extension error pattern

Tests: 15 new tests (TestLeanPreset + TestBundledPresetLocator)

Author: mnriem

presets/catalog.json

@@ -1,6 +1,22 @@
 {
   "schema_version": "1.0",
-  "updated_at": "2026-03-10T00:00:00Z",
+  "updated_at": "2026-04-10T00:00:00Z",
   "catalog_url": "https://raw.githubusercontent.com/github/spec-kit/main/presets/catalog.json",
-  "presets": {}
+  "presets": {
+    "lean": {
+      "name": "Lean Workflow",
+      "id": "lean",
+      "version": "1.0.0",
+      "description": "Minimal core workflow commands — just the prompt, just the artifact",
+      "author": "github",
+      "repository": "https://github.com/github/spec-kit",
+      "bundled": true,
+      "tags": [
+        "lean",
+        "minimal",
+        "workflow",
+        "core"
+      ]
+    }
+  }
 }

presets/lean/commands/speckit.constitution.md

@@ -0,0 +1,15 @@
+---
+description: Create or update the project constitution.
+---
+
+## User Input
+
+```text
+$ARGUMENTS
+```
+
+## Outline
+
+1. Create or update the project constitution and store it in `.specify/memory/constitution.md`.
+   - Project name, guiding principles, non-negotiable rules
+   - Derive from user input and existing repo context (README, docs)

presets/lean/commands/speckit.implement.md

@@ -0,0 +1,23 @@
+---
+description: Execute the implementation plan by processing all tasks in tasks.md.
+---
+
+## User Input
+
+```text
+$ARGUMENTS
+```
+
+## Outline
+
+1. Read `.specify/feature.json` to get the feature directory path.
+
+2. **Load context**: `constitution.md` and `spec.md` and `plan.md` and `tasks.md`.
+
+3. **Execute tasks** phase by phase:
+   - Complete each phase before moving to the next
+   - Respect dependencies: sequential tasks in order, `[P]` tasks can run together
+   - Mark completed tasks as `[X]` in tasks.md
+   - Halt on failure for sequential tasks; continue and report for parallel tasks
+
+4. **Validate**: Verify all tasks are completed and the implementation matches the spec.

presets/lean/commands/speckit.plan.md

@@ -0,0 +1,19 @@
+---
+description: Create a plan and store it in plan.md.
+---
+
+## User Input
+
+```text
+$ARGUMENTS
+```
+
+## Outline
+
+1. Read `.specify/feature.json` to get the feature directory path.
+
+2. **Load context**: `constitution.md` and `spec.md`.
+
+3. Create an implementation plan and store it in `<feature_directory>/plan.md`.
+   - Technical context: tech stack, dependencies, project structure
+   - Design decisions, architecture, file structure

presets/lean/commands/speckit.specify.md

@@ -0,0 +1,23 @@
+---
+description: Create a specification and store it in spec.md.
+---
+
+## User Input
+
+```text
+$ARGUMENTS
+```
+
+## Outline
+
+1. **Ask the user** for the feature directory path (e.g., `specs/my-feature`). Do not proceed until provided.
+
+2. Create the directory and write `.specify/feature.json`:
+   ```json
+   { "feature_directory": "<feature_directory>" }
+   ```
+
+3. Create a specification from the user input and store it in `<feature_directory>/spec.md`.
+   - Overview, functional requirements, user scenarios, success criteria
+   - Every requirement must be testable
+   - Make informed defaults for unspecified details

presets/lean/commands/speckit.tasks.md

@@ -0,0 +1,19 @@
+---
+description: Create the tasks needed for implementation and store it in tasks.md.
+---
+
+## User Input
+
+```text
+$ARGUMENTS
+```
+
+## Outline
+
+1. Read `.specify/feature.json` to get the feature directory path.
+
+2. **Load context**: `constitution.md` and `spec.md` and `plan.md`.
+
+3. Create dependency-ordered implementation tasks and store them in `<feature_directory>/tasks.md`.
+   - Every task uses checklist format: `- [ ] [TaskID] Description with file path`
+   - Organized by phase: setup, foundational, user stories in priority order, polish

presets/lean/preset.yml

@@ -0,0 +1,50 @@
+schema_version: "1.0"
+
+preset:
+  id: "lean"
+  name: "Lean Workflow"
+  version: "1.0.0"
+  description: "Minimal core workflow commands — just the prompt, just the artifact"
+  author: "github"
+  repository: "https://github.com/github/spec-kit"
+  license: "MIT"
+
+requires:
+  speckit_version: ">=0.1.0"
+
+provides:
+  templates:
+    - type: "command"
+      name: "speckit.specify"
+      file: "commands/speckit.specify.md"
+      description: "Lean specify — create spec.md from a feature description"
+      replaces: "speckit.specify"
+
+    - type: "command"
+      name: "speckit.plan"
+      file: "commands/speckit.plan.md"
+      description: "Lean plan — create plan.md from the spec"
+      replaces: "speckit.plan"
+
+    - type: "command"
+      name: "speckit.tasks"
+      file: "commands/speckit.tasks.md"
+      description: "Lean tasks — create tasks.md from plan and spec"
+      replaces: "speckit.tasks"
+
+    - type: "command"
+      name: "speckit.implement"
+      file: "commands/speckit.implement.md"
+      description: "Lean implement — execute tasks from tasks.md"
+      replaces: "speckit.implement"
+
+    - type: "command"
+      name: "speckit.constitution"
+      file: "commands/speckit.constitution.md"
+      description: "Lean constitution — create or update project constitution"
+      replaces: "speckit.constitution"
+
+tags:
+  - "lean"
+  - "minimal"
+  - "workflow"

pyproject.toml

@@ -41,6 +41,8 @@ packages = ["src/specify_cli"]
 "scripts/powershell" = "specify_cli/core_pack/scripts/powershell"
 # Bundled extensions (installable via `specify extension add <name>`)
 "extensions/git" = "specify_cli/core_pack/extensions/git"
+# Bundled presets (installable via `specify preset add <name>` or `specify init --preset <name>`)
+"presets/lean" = "specify_cli/core_pack/presets/lean"
 
 [project.optional-dependencies]
 test = [

src/specify_cli/__init__.py

@@ -621,6 +621,31 @@ def _locate_bundled_extension(extension_id: str) -> Path | None:
     return None
 
 
+def _locate_bundled_preset(preset_id: str) -> Path | None:
+    """Return the path to a bundled preset, or None.
+
+    Checks the wheel's core_pack first, then falls back to the
+    source-checkout ``presets/<id>/`` directory.
+    """
+    import re as _re
+    if not _re.match(r'^[a-z0-9-]+$', preset_id):
+        return None
+
+    core = _locate_core_pack()
+    if core is not None:
+        candidate = core / "presets" / preset_id
+        if (candidate / "preset.yml").is_file():
+            return candidate
+
+    # Source-checkout / editable install: look relative to repo root
+    repo_root = Path(__file__).parent.parent.parent
+    candidate = repo_root / "presets" / preset_id
+    if (candidate / "preset.yml").is_file():
+        return candidate
+
+    return None
+
+
 def _install_shared_infra(
     project_path: Path,
     script_type: str,
@@ -1266,27 +1291,41 @@ def init(
                     preset_manager = PresetManager(project_path)
                     speckit_ver = get_speckit_version()
 
-                    # Try local directory first, then catalog
+                    # Try local directory first, then bundled, then catalog
                     local_path = Path(preset).resolve()
                     if local_path.is_dir() and (local_path / "preset.yml").exists():
                         preset_manager.install_from_directory(local_path, speckit_ver)
                     else:
-                        preset_catalog = PresetCatalog(project_path)
-                        pack_info = preset_catalog.get_pack_info(preset)
-                        if not pack_info:
-                            console.print(f"[yellow]Warning:[/yellow] Preset '{preset}' not found in catalog. Skipping.")
+                        bundled_path = _locate_bundled_preset(preset)
+                        if bundled_path:
+                            preset_manager.install_from_directory(bundled_path, speckit_ver)
                         else:
-                            try:
-                                zip_path = preset_catalog.download_pack(preset)
-                                preset_manager.install_from_zip(zip_path, speckit_ver)
-                                # Clean up downloaded ZIP to avoid cache accumulation
+                            preset_catalog = PresetCatalog(project_path)
+                            pack_info = preset_catalog.get_pack_info(preset)
+                            if not pack_info:
+                                console.print(f"[yellow]Warning:[/yellow] Preset '{preset}' not found in catalog. Skipping.")
+                            elif pack_info.get("bundled") and not pack_info.get("download_url"):
+                                from .extensions import REINSTALL_COMMAND
+                                console.print(
+                                    f"[yellow]Warning:[/yellow] Preset '{preset}' is bundled with spec-kit "
+                                    f"but could not be found in the installed package."
+                                )
+                                console.print(
+                                    "This usually means the spec-kit installation is incomplete or corrupted."
+                                )
+                                console.print(f"Try reinstalling: {REINSTALL_COMMAND}")
+                            else:
                                 try:
-                                    zip_path.unlink(missing_ok=True)
-                                except OSError:
-                                    # Best-effort cleanup; failure to delete is non-fatal
-                                    pass
-                            except PresetError as preset_err:
-                                console.print(f"[yellow]Warning:[/yellow] Failed to install preset '{preset}': {preset_err}")
+                                    zip_path = preset_catalog.download_pack(preset)
+                                    preset_manager.install_from_zip(zip_path, speckit_ver)
+                                    # Clean up downloaded ZIP to avoid cache accumulation
+                                    try:
+                                        zip_path.unlink(missing_ok=True)
+                                    except OSError:
+                                        # Best-effort cleanup; failure to delete is non-fatal
+                                        pass
+                                except PresetError as preset_err:
+                                    console.print(f"[yellow]Warning:[/yellow] Failed to install preset '{preset}': {preset_err}")
                 except Exception as preset_err:
                     console.print(f"[yellow]Warning:[/yellow] Failed to install preset: {preset_err}")
 
@@ -2140,28 +2179,50 @@ def preset_add(
             console.print(f"[green]✓[/green] Preset '{manifest.name}' v{manifest.version} installed (priority {priority})")
 
         elif pack_id:
-            catalog = PresetCatalog(project_root)
-            pack_info = catalog.get_pack_info(pack_id)
+            # Try bundled preset first, then catalog
+            bundled_path = _locate_bundled_preset(pack_id)
+            if bundled_path:
+                console.print(f"Installing bundled preset [cyan]{pack_id}[/cyan]...")
+                manifest = manager.install_from_directory(bundled_path, speckit_version, priority)
+                console.print(f"[green]✓[/green] Preset '{manifest.name}' v{manifest.version} installed (priority {priority})")
+            else:
+                catalog = PresetCatalog(project_root)
+                pack_info = catalog.get_pack_info(pack_id)
 
-            if not pack_info:
-                console.print(f"[red]Error:[/red] Preset '{pack_id}' not found in catalog")
-                raise typer.Exit(1)
+                if not pack_info:
+                    console.print(f"[red]Error:[/red] Preset '{pack_id}' not found in catalog")
+                    raise typer.Exit(1)
 
-            if not pack_info.get("_install_allowed", True):
-                catalog_name = pack_info.get("_catalog_name", "unknown")
-                console.print(f"[red]Error:[/red] Preset '{pack_id}' is from the '{catalog_name}' catalog which is discovery-only (install not allowed).")
-                console.print("Add the catalog with --install-allowed or install from the preset's repository directly with --from.")
-                raise typer.Exit(1)
+                # Bundled presets should have been caught above; if we reach
+                # here the bundled files are missing from the installation.
+                if pack_info.get("bundled") and not pack_info.get("download_url"):
+                    from .extensions import REINSTALL_COMMAND
+                    console.print(
+                        f"[red]Error:[/red] Preset '{pack_id}' is bundled with spec-kit "
+                        f"but could not be found in the installed package."
+                    )
+                    console.print(
+                        "\nThis usually means the spec-kit installation is incomplete or corrupted."
+                    )
+                    console.print("Try reinstalling spec-kit:")
+                    console.print(f"  {REINSTALL_COMMAND}")
+                    raise typer.Exit(1)
 
-            console.print(f"Installing preset [cyan]{pack_info.get('name', pack_id)}[/cyan]...")
+                if not pack_info.get("_install_allowed", True):
+                    catalog_name = pack_info.get("_catalog_name", "unknown")
+                    console.print(f"[red]Error:[/red] Preset '{pack_id}' is from the '{catalog_name}' catalog which is discovery-only (install not allowed).")
+                    console.print("Add the catalog with --install-allowed or install from the preset's repository directly with --from.")
+                    raise typer.Exit(1)
 
-            try:
-                zip_path = catalog.download_pack(pack_id)
-                manifest = manager.install_from_zip(zip_path, speckit_version, priority)
-                console.print(f"[green]✓[/green] Preset '{manifest.name}' v{manifest.version} installed (priority {priority})")
-            finally:
-                if 'zip_path' in locals() and zip_path.exists():
-                    zip_path.unlink(missing_ok=True)
+                console.print(f"Installing preset [cyan]{pack_info.get('name', pack_id)}[/cyan]...")
+
+                try:
+                    zip_path = catalog.download_pack(pack_id)
+                    manifest = manager.install_from_zip(zip_path, speckit_version, priority)
+                    console.print(f"[green]✓[/green] Preset '{manifest.name}' v{manifest.version} installed (priority {priority})")
+                finally:
+                    if 'zip_path' in locals() and zip_path.exists():
+                        zip_path.unlink(missing_ok=True)
         else:
             console.print("[red]Error:[/red] Specify a preset ID, --from URL, or --dev path")
             raise typer.Exit(1)

src/specify_cli/presets.py

@@ -1587,6 +1587,15 @@ def download_pack(
                 f"Preset '{pack_id}' not found in catalog"
             )
 
+        # Bundled presets without a download URL must be installed locally
+        if pack_info.get("bundled") and not pack_info.get("download_url"):
+            raise PresetError(
+                f"Preset '{pack_id}' is bundled with spec-kit and has no download URL. "
+                f"It should be installed from the local package. "
+                f"Use 'specify preset add {pack_id}' to install from the bundled package, "
+                f"or reinstall spec-kit if the bundled files are missing."
+            )
+
         if not pack_info.get("_install_allowed", True):
             catalog_name = pack_info.get("_catalog_name", "unknown")
             raise PresetError(