sem Integration
Foundation patterns for using
sem semantic
diffs in night-market skills.
When To Use
Consult this skill when building or modifying skills that
consume git diff output. It provides the detection,
installation, and fallback patterns.
When NOT To Use
- Direct sem CLI usage (just run
sem diff yourself)
- Skills that don't consume diff output
Detection Pattern
Check sem availability once per session:
_sem_check() {
local cache="${CLAUDE_CODE_TMPDIR:-/tmp}/sem-available"
if [ -f "$cache" ]; then
cat "$cache"
return
fi
if command -v sem &>/dev/null; then
echo "1" | tee "$cache"
else
echo "0" | tee "$cache"
fi
}
When _sem_check returns 0, offer installation.
See modules/detection.md for install-on-first-use
logic and platform-specific commands.
Semantic Diff Pattern
Primary path (sem available):
sem diff --format json <baseline>
Fallback path (sem unavailable):
git diff --name-only --diff-filter=A <baseline>
git diff --name-only --diff-filter=M <baseline>
git diff --name-only --diff-filter=D <baseline>
git diff --name-only --diff-filter=R <baseline>
See modules/fallback.md for output normalization
that produces the same entity schema from both paths.
Impact Analysis Pattern
Primary path (sem available):
sem impact --json <file-or-entity>
Fallback path (sem unavailable): use rg/grep to trace
callers by filename. See modules/fallback.md.
Exit Criteria
