Skill Portability Checker

What it does

Skills with companion scripts (.py, .sh) can silently fail on machines where their dependencies aren't installed. A skill written on macOS may call brew, pbcopy, or use /usr/local/bin paths that don't exist on Linux. A Python script may import pandas on a system without it.

Skill Portability Checker:

1. Scans companion scripts for OS-specific patterns and external binary calls
2. Checks whether those binaries are present on the current system (PATH lookup + which)
3. Cross-checks against the skill's declared os_filter: frontmatter field (if any)
4. Reports portability issues before the skill fails at runtime

Frontmatter field checked

---
name: my-skill
os_filter: [macos]   # optional: ["macos", "linux", "windows"]
---

If os_filter: is absent the skill is treated as cross-platform. The checker then warns if OS-specific calls are detected without a corresponding os_filter:.

Checks performed

Check	Description
OS_SPECIFIC_CALL	Script calls macOS/Linux/Windows-only binary without os_filter:
MISSING_BINARY	Required binary not found on current system PATH
BREW_ONLY	Script uses brew (macOS-only) but os_filter: includes non-macOS
PYTHON_IMPORT	Script imports a non-stdlib module; checks if importable
HARDCODED_PATH	Absolute path that doesn't exist on this machine (/usr/local, C:\)

How to use

python3 check.py --check                   # Full portability scan
python3 check.py --check --skill my-skill  # Single skill
python3 check.py --fix-hints my-skill      # Print fix suggestions
python3 check.py --format json

Procedure

Step 1 — Run the scan

python3 check.py --check

Step 2 — Triage FAILs first

• MISSING_BINARY: The script calls a binary that isn't installed. Either install it or add a graceful fallback in the script.
• OS_SPECIFIC_CALL without os_filter: Add os_filter: [macos] (or whichever OS applies) to the frontmatter so users on other platforms know the skill won't work.

Step 3 — Review WARNs

• PYTHON_IMPORT: Install the missing module or add a try/except ImportError with a graceful degradation path (like HAS_MODULE = False).
• HARDCODED_PATH: Replace with Path.home() or environment-variable-based paths.

Step 4 — Add os_filter when needed

If a skill genuinely only works on one OS, declare it:

os_filter: [macos]

This prevents the skill from being shown as broken on other platforms — it simply won't be loaded there.

Output example

Skill Portability Report — linux (Python 3.11)
────────────────────────────────────────────────
32 skills checked | 1 FAIL | 2 WARN

FAIL  obsidian-sync: MISSING_BINARY
      sync.py calls `osascript` — not found on this system
      Fix: add os_filter: [macos] to frontmatter (osascript is macOS-only)

WARN  morning-briefing: PYTHON_IMPORT
      run.py imports `pync` — not importable on this system
      Fix: wrap in try/except ImportError and degrade gracefully