athola 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 diffyourself) - Skills that don't consume diff output
Detection Pattern
Check sem availability once per session:
# Detection (cache 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 "$cache"
fi
}
When _sem_check returns 0, offer installation.
See modules/detection.md for install-on-first-use
logic and platform-specific commands.
Semantic Diff Pattern
Primary path (sem available):
sem diff --format json <baseline>
Fallback path (sem unavailable):
git diff --name-only --diff-filter=A <baseline>
git diff --name-only --diff-filter=M <baseline>
git diff --name-only --diff-filter=D <baseline>
git diff --name-only --diff-filter=R <baseline>
See modules/fallback.md for output normalization
that produces the same entity schema from both paths.
Impact Analysis Pattern
Primary path (sem available):
sem impact --json <file-or-entity>
Fallback path (sem unavailable): use rg/grep to trace
callers by filename. See modules/fallback.md.
Exit Criteria
-
_sem_checkresult cached per session at${CLAUDE_CODE_TMPDIR:-/tmp}/sem-available; detection command runs at most once per session regardless of how many skills invoke it - When sem is unavailable, install offer presented and fallback
path used automatically (
git diff --name-only --diff-filter=variants); no silent failure - Fallback output normalized to the same entity schema as sem
JSON output per
modules/fallback.md; consumers downstream see the same structure from both paths - Skills consuming this integration declare
dependencies: [leyline:sem-integration]in frontmatter rather than reimplementing the detection pattern
Source: athola/claude-night-market → plugins/leyline/skills/sem-integration/SKILL.md