fix(skill-creator): restore validation and align packaging docs

nanobot/skills/skill-creator/SKILL.md

@@ -268,6 +268,8 @@ Skip this step only if the skill being developed already exists, and iteration o
 
 When creating a new skill from scratch, always run the `init_skill.py` script. The script conveniently generates a new template skill directory that automatically includes everything a skill requires, making the skill creation process much more efficient and reliable.
 
+For `nanobot`, custom skills should live under the active workspace `skills/` directory so they can be discovered automatically at runtime (for example, `<workspace>/skills/my-skill/SKILL.md`).
+
 Usage:
 
 ```bash
@@ -277,9 +279,9 @@ scripts/init_skill.py <skill-name> --path <output-directory> [--resources script
 Examples:
 
 ```bash
-scripts/init_skill.py my-skill --path skills/public
+scripts/init_skill.py my-skill --path ./workspace/skills
-scripts/init_skill.py my-skill --path skills/public --resources scripts,references
+scripts/init_skill.py my-skill --path ./workspace/skills --resources scripts,references
-scripts/init_skill.py my-skill --path skills/public --resources scripts --examples
+scripts/init_skill.py my-skill --path ./workspace/skills --resources scripts --examples
 ```
 
 The script:
@@ -326,7 +328,7 @@ Write the YAML frontmatter with `name` and `description`:
   - Include all "when to use" information here - Not in the body. The body is only loaded after triggering, so "When to Use This Skill" sections in the body are not helpful to the agent.
   - Example description for a `docx` skill: "Comprehensive document creation, editing, and analysis with support for tracked changes, comments, formatting preservation, and text extraction. Use when the agent needs to work with professional documents (.docx files) for: (1) Creating new documents, (2) Modifying or editing content, (3) Working with tracked changes, (4) Adding comments, or any other document tasks"
 
-Do not include any other fields in YAML frontmatter.
+Keep frontmatter minimal. In `nanobot`, `metadata` and `always` are also supported when needed, but avoid adding extra fields unless they are actually required.
 
 ##### Body
 

nanobot/skills/skill-creator/scripts/package_skill.py

@@ -3,11 +3,11 @@
 Skill Packager - Creates a distributable .skill file of a skill folder
 
 Usage:
-    python utils/package_skill.py <path/to/skill-folder> [output-directory]
+    python package_skill.py <path/to/skill-folder> [output-directory]
 
 Example:
-    python utils/package_skill.py skills/public/my-skill
+    python package_skill.py skills/public/my-skill
-    python utils/package_skill.py skills/public/my-skill ./dist
+    python package_skill.py skills/public/my-skill ./dist
 """
 
 import sys
@@ -25,6 +25,14 @@ def _is_within(path: Path, root: Path) -> bool:
         return False
 
 
+def _cleanup_partial_archive(skill_filename: Path) -> None:
+    try:
+        if skill_filename.exists():
+            skill_filename.unlink()
+    except OSError:
+        pass
+
+
 def package_skill(skill_path, output_dir=None):
     """
     Package a skill folder into a .skill file.
@@ -74,49 +82,56 @@ def package_skill(skill_path, output_dir=None):
 
     EXCLUDED_DIRS = {".git", ".svn", ".hg", "__pycache__", "node_modules"}
 
+    files_to_package = []
+    resolved_archive = skill_filename.resolve()
+
+    for file_path in skill_path.rglob("*"):
+        # Fail closed on symlinks so the packaged contents are explicit and predictable.
+        if file_path.is_symlink():
+            print(f"[ERROR] Symlink not allowed in packaged skill: {file_path}")
+            _cleanup_partial_archive(skill_filename)
+            return None
+
+        rel_parts = file_path.relative_to(skill_path).parts
+        if any(part in EXCLUDED_DIRS for part in rel_parts):
+            continue
+
+        if file_path.is_file():
+            resolved_file = file_path.resolve()
+            if not _is_within(resolved_file, skill_path):
+                print(f"[ERROR] File escapes skill root: {file_path}")
+                _cleanup_partial_archive(skill_filename)
+                return None
+            # If output lives under skill_path, avoid writing archive into itself.
+            if resolved_file == resolved_archive:
+                print(f"[WARN] Skipping output archive: {file_path}")
+                continue
+            files_to_package.append(file_path)
+
     # Create the .skill file (zip format)
     try:
         with zipfile.ZipFile(skill_filename, "w", zipfile.ZIP_DEFLATED) as zipf:
-            # Walk through the skill directory
+            for file_path in files_to_package:
-            for file_path in skill_path.rglob("*"):
+                # Calculate the relative path within the zip.
-                # Security: never follow or package symlinks.
+                arcname = Path(skill_name) / file_path.relative_to(skill_path)
-                if file_path.is_symlink():
+                zipf.write(file_path, arcname)
-                    print(f"[WARN] Skipping symlink: {file_path}")
+                print(f"  Added: {arcname}")
-                    continue
-
-                rel_parts = file_path.relative_to(skill_path).parts
-                if any(part in EXCLUDED_DIRS for part in rel_parts):
-                    continue
-
-                if file_path.is_file():
-                    resolved_file = file_path.resolve()
-                    if not _is_within(resolved_file, skill_path):
-                        print(f"[ERROR] File escapes skill root: {file_path}")
-                        return None
-                    # If output lives under skill_path, avoid writing archive into itself.
-                    if resolved_file == skill_filename.resolve():
-                        print(f"[WARN] Skipping output archive: {file_path}")
-                        continue
-
-                    # Calculate the relative path within the zip.
-                    arcname = Path(skill_name) / file_path.relative_to(skill_path)
-                    zipf.write(file_path, arcname)
-                    print(f"  Added: {arcname}")
 
         print(f"\n[OK] Successfully packaged skill to: {skill_filename}")
         return skill_filename
 
     except Exception as e:
+        _cleanup_partial_archive(skill_filename)
         print(f"[ERROR] Error creating .skill file: {e}")
         return None
 
 
 def main():
     if len(sys.argv) < 2:
-        print("Usage: python utils/package_skill.py <path/to/skill-folder> [output-directory]")
+        print("Usage: python package_skill.py <path/to/skill-folder> [output-directory]")
         print("\nExample:")
-        print("  python utils/package_skill.py skills/public/my-skill")
+        print("  python package_skill.py skills/public/my-skill")
-        print("  python utils/package_skill.py skills/public/my-skill ./dist")
+        print("  python package_skill.py skills/public/my-skill ./dist")
         sys.exit(1)
 
     skill_path = sys.argv[1]

nanobot/skills/skill-creator/scripts/quick_validate.py

@@ -0,0 +1,213 @@
+#!/usr/bin/env python3
+"""
+Minimal validator for nanobot skill folders.
+"""
+
+import re
+import sys
+from pathlib import Path
+from typing import Optional
+
+try:
+    import yaml
+except ModuleNotFoundError:
+    yaml = None
+
+MAX_SKILL_NAME_LENGTH = 64
+ALLOWED_FRONTMATTER_KEYS = {
+    "name",
+    "description",
+    "metadata",
+    "always",
+    "license",
+    "allowed-tools",
+}
+ALLOWED_RESOURCE_DIRS = {"scripts", "references", "assets"}
+PLACEHOLDER_MARKERS = ("[todo", "todo:")
+
+
+def _extract_frontmatter(content: str) -> Optional[str]:
+    lines = content.splitlines()
+    if not lines or lines[0].strip() != "---":
+        return None
+    for i in range(1, len(lines)):
+        if lines[i].strip() == "---":
+            return "\n".join(lines[1:i])
+    return None
+
+
+def _parse_simple_frontmatter(frontmatter_text: str) -> Optional[dict[str, str]]:
+    """Fallback parser for simple frontmatter when PyYAML is unavailable."""
+    parsed: dict[str, str] = {}
+    current_key: Optional[str] = None
+    multiline_key: Optional[str] = None
+
+    for raw_line in frontmatter_text.splitlines():
+        stripped = raw_line.strip()
+        if not stripped or stripped.startswith("#"):
+            continue
+
+        is_indented = raw_line[:1].isspace()
+        if is_indented:
+            if current_key is None:
+                return None
+            current_value = parsed[current_key]
+            parsed[current_key] = f"{current_value}\n{stripped}" if current_value else stripped
+            continue
+
+        if ":" not in stripped:
+            return None
+
+        key, value = stripped.split(":", 1)
+        key = key.strip()
+        value = value.strip()
+        if not key:
+            return None
+
+        if value in {"|", ">"}:
+            parsed[key] = ""
+            current_key = key
+            multiline_key = key
+            continue
+
+        if (value.startswith('"') and value.endswith('"')) or (
+            value.startswith("'") and value.endswith("'")
+        ):
+            value = value[1:-1]
+        parsed[key] = value
+        current_key = key
+        multiline_key = None
+
+    if multiline_key is not None and multiline_key not in parsed:
+        return None
+    return parsed
+
+
+def _load_frontmatter(frontmatter_text: str) -> tuple[Optional[dict], Optional[str]]:
+    if yaml is not None:
+        try:
+            frontmatter = yaml.safe_load(frontmatter_text)
+        except yaml.YAMLError as exc:
+            return None, f"Invalid YAML in frontmatter: {exc}"
+        if not isinstance(frontmatter, dict):
+            return None, "Frontmatter must be a YAML dictionary"
+        return frontmatter, None
+
+    frontmatter = _parse_simple_frontmatter(frontmatter_text)
+    if frontmatter is None:
+        return None, "Invalid YAML in frontmatter: unsupported syntax without PyYAML installed"
+    return frontmatter, None
+
+
+def _validate_skill_name(name: str, folder_name: str) -> Optional[str]:
+    if not re.fullmatch(r"[a-z0-9]+(?:-[a-z0-9]+)*", name):
+        return (
+            f"Name '{name}' should be hyphen-case "
+            "(lowercase letters, digits, and single hyphens only)"
+        )
+    if len(name) > MAX_SKILL_NAME_LENGTH:
+        return (
+            f"Name is too long ({len(name)} characters). "
+            f"Maximum is {MAX_SKILL_NAME_LENGTH} characters."
+        )
+    if name != folder_name:
+        return f"Skill name '{name}' must match directory name '{folder_name}'"
+    return None
+
+
+def _validate_description(description: str) -> Optional[str]:
+    trimmed = description.strip()
+    if not trimmed:
+        return "Description cannot be empty"
+    lowered = trimmed.lower()
+    if any(marker in lowered for marker in PLACEHOLDER_MARKERS):
+        return "Description still contains TODO placeholder text"
+    if "<" in trimmed or ">" in trimmed:
+        return "Description cannot contain angle brackets (< or >)"
+    if len(trimmed) > 1024:
+        return f"Description is too long ({len(trimmed)} characters). Maximum is 1024 characters."
+    return None
+
+
+def validate_skill(skill_path):
+    """Validate a skill folder structure and required frontmatter."""
+    skill_path = Path(skill_path).resolve()
+
+    if not skill_path.exists():
+        return False, f"Skill folder not found: {skill_path}"
+    if not skill_path.is_dir():
+        return False, f"Path is not a directory: {skill_path}"
+
+    skill_md = skill_path / "SKILL.md"
+    if not skill_md.exists():
+        return False, "SKILL.md not found"
+
+    try:
+        content = skill_md.read_text(encoding="utf-8")
+    except OSError as exc:
+        return False, f"Could not read SKILL.md: {exc}"
+
+    frontmatter_text = _extract_frontmatter(content)
+    if frontmatter_text is None:
+        return False, "Invalid frontmatter format"
+
+    frontmatter, error = _load_frontmatter(frontmatter_text)
+    if error:
+        return False, error
+
+    unexpected_keys = sorted(set(frontmatter.keys()) - ALLOWED_FRONTMATTER_KEYS)
+    if unexpected_keys:
+        allowed = ", ".join(sorted(ALLOWED_FRONTMATTER_KEYS))
+        unexpected = ", ".join(unexpected_keys)
+        return (
+            False,
+            f"Unexpected key(s) in SKILL.md frontmatter: {unexpected}. Allowed properties are: {allowed}",
+        )
+
+    if "name" not in frontmatter:
+        return False, "Missing 'name' in frontmatter"
+    if "description" not in frontmatter:
+        return False, "Missing 'description' in frontmatter"
+
+    name = frontmatter["name"]
+    if not isinstance(name, str):
+        return False, f"Name must be a string, got {type(name).__name__}"
+    name_error = _validate_skill_name(name.strip(), skill_path.name)
+    if name_error:
+        return False, name_error
+
+    description = frontmatter["description"]
+    if not isinstance(description, str):
+        return False, f"Description must be a string, got {type(description).__name__}"
+    description_error = _validate_description(description)
+    if description_error:
+        return False, description_error
+
+    always = frontmatter.get("always")
+    if always is not None and not isinstance(always, bool):
+        return False, f"'always' must be a boolean, got {type(always).__name__}"
+
+    for child in skill_path.iterdir():
+        if child.name == "SKILL.md":
+            continue
+        if child.is_dir() and child.name in ALLOWED_RESOURCE_DIRS:
+            continue
+        if child.is_symlink():
+            continue
+        return (
+            False,
+            f"Unexpected file or directory in skill root: {child.name}. "
+            "Only SKILL.md, scripts/, references/, and assets/ are allowed.",
+        )
+
+    return True, "Skill is valid!"
+
+
+if __name__ == "__main__":
+    if len(sys.argv) != 2:
+        print("Usage: python quick_validate.py <skill_directory>")
+        sys.exit(1)
+
+    valid, message = validate_skill(sys.argv[1])
+    print(message)
+    sys.exit(0 if valid else 1)

tests/test_skill_creator_scripts.py

@@ -0,0 +1,127 @@
+import importlib
+import shutil
+import sys
+import zipfile
+from pathlib import Path
+
+
+SCRIPT_DIR = Path("nanobot/skills/skill-creator/scripts").resolve()
+if str(SCRIPT_DIR) not in sys.path:
+    sys.path.insert(0, str(SCRIPT_DIR))
+
+init_skill = importlib.import_module("init_skill")
+package_skill = importlib.import_module("package_skill")
+quick_validate = importlib.import_module("quick_validate")
+
+
+def test_init_skill_creates_expected_files(tmp_path: Path) -> None:
+    skill_dir = init_skill.init_skill(
+        "demo-skill",
+        tmp_path,
+        ["scripts", "references", "assets"],
+        include_examples=True,
+    )
+
+    assert skill_dir == tmp_path / "demo-skill"
+    assert (skill_dir / "SKILL.md").exists()
+    assert (skill_dir / "scripts" / "example.py").exists()
+    assert (skill_dir / "references" / "api_reference.md").exists()
+    assert (skill_dir / "assets" / "example_asset.txt").exists()
+
+
+def test_validate_skill_accepts_existing_skill_creator() -> None:
+    valid, message = quick_validate.validate_skill(
+        Path("nanobot/skills/skill-creator").resolve()
+    )
+
+    assert valid, message
+
+
+def test_validate_skill_rejects_placeholder_description(tmp_path: Path) -> None:
+    skill_dir = tmp_path / "placeholder-skill"
+    skill_dir.mkdir()
+    (skill_dir / "SKILL.md").write_text(
+        "---\n"
+        "name: placeholder-skill\n"
+        'description: "[TODO: fill me in]"\n'
+        "---\n"
+        "# Placeholder\n",
+        encoding="utf-8",
+    )
+
+    valid, message = quick_validate.validate_skill(skill_dir)
+
+    assert not valid
+    assert "TODO placeholder" in message
+
+
+def test_validate_skill_rejects_root_files_outside_allowed_dirs(tmp_path: Path) -> None:
+    skill_dir = tmp_path / "bad-root-skill"
+    skill_dir.mkdir()
+    (skill_dir / "SKILL.md").write_text(
+        "---\n"
+        "name: bad-root-skill\n"
+        "description: Valid description\n"
+        "---\n"
+        "# Skill\n",
+        encoding="utf-8",
+    )
+    (skill_dir / "README.md").write_text("extra\n", encoding="utf-8")
+
+    valid, message = quick_validate.validate_skill(skill_dir)
+
+    assert not valid
+    assert "Unexpected file or directory in skill root" in message
+
+
+def test_package_skill_creates_archive(tmp_path: Path) -> None:
+    skill_dir = tmp_path / "package-me"
+    skill_dir.mkdir()
+    (skill_dir / "SKILL.md").write_text(
+        "---\n"
+        "name: package-me\n"
+        "description: Package this skill.\n"
+        "---\n"
+        "# Skill\n",
+        encoding="utf-8",
+    )
+    scripts_dir = skill_dir / "scripts"
+    scripts_dir.mkdir()
+    (scripts_dir / "helper.py").write_text("print('ok')\n", encoding="utf-8")
+
+    archive_path = package_skill.package_skill(skill_dir, tmp_path / "dist")
+
+    assert archive_path == (tmp_path / "dist" / "package-me.skill")
+    assert archive_path.exists()
+    with zipfile.ZipFile(archive_path, "r") as archive:
+        names = set(archive.namelist())
+    assert "package-me/SKILL.md" in names
+    assert "package-me/scripts/helper.py" in names
+
+
+def test_package_skill_rejects_symlink(tmp_path: Path) -> None:
+    skill_dir = tmp_path / "symlink-skill"
+    skill_dir.mkdir()
+    (skill_dir / "SKILL.md").write_text(
+        "---\n"
+        "name: symlink-skill\n"
+        "description: Reject symlinks during packaging.\n"
+        "---\n"
+        "# Skill\n",
+        encoding="utf-8",
+    )
+    scripts_dir = skill_dir / "scripts"
+    scripts_dir.mkdir()
+    target = tmp_path / "outside.txt"
+    target.write_text("secret\n", encoding="utf-8")
+    link = scripts_dir / "outside.txt"
+
+    try:
+        link.symlink_to(target)
+    except (OSError, NotImplementedError):
+        return
+
+    archive_path = package_skill.package_skill(skill_dir, tmp_path / "dist")
+
+    assert archive_path is None
+    assert not (tmp_path / "dist" / "symlink-skill.skill").exists()