diff --git a/.gitignore b/.gitignore
index e367f05..82ca0e9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -22,3 +22,6 @@ htmlcov/
 
 # Root vendor/ is accidental - real vendored client lives at scripts/lib/vendor/bird-search/
 /vendor/
+
+# build artifact from scripts/build-skill.sh
+/dist/
diff --git a/scripts/build-skill.sh b/scripts/build-skill.sh
new file mode 100755
index 0000000..fadf72a
--- /dev/null
+++ b/scripts/build-skill.sh
@@ -0,0 +1,38 @@
+#!/usr/bin/env bash
+# build-skill.sh - package this repo as a claude.ai-upload-ready .skill file
+# Usage: bash scripts/build-skill.sh  (run from repo root)
+#
+# Produces dist/last30days.skill, a zip with a single top-level `last30days/`
+# directory containing SKILL.md and the scripts/ runtime. See
+# docs/plans/2026-04-14-001-fix-skill-upload-200-file-limit-plan.md.
+set -euo pipefail
+
+REPO_ROOT="$(cd "$(dirname "$0")/.." && pwd)"
+cd "$REPO_ROOT"
+
+if ! git diff --quiet || ! git diff --cached --quiet; then
+  echo "error: working tree is dirty; commit or stash before building" >&2
+  exit 1
+fi
+
+mkdir -p dist
+OUT="dist/last30days.skill"
+git archive --format=zip --prefix=last30days/ --output="$OUT" HEAD
+
+COUNT=$(unzip -l "$OUT" | tail -1 | awk '{print $2}')
+SIZE=$(du -h "$OUT" | cut -f1)
+
+if [ "$COUNT" -gt 200 ]; then
+  echo "error: $COUNT files in zip, claude.ai's cap is 200" >&2
+  echo "       check .gitattributes export-ignore entries" >&2
+  exit 1
+fi
+
+SKILL_MD_COUNT=$(unzip -l "$OUT" | grep -c "SKILL.md" || true)
+if [ "$SKILL_MD_COUNT" -ne 1 ]; then
+  echo "error: expected exactly one SKILL.md, found $SKILL_MD_COUNT" >&2
+  exit 1
+fi
+
+echo "built $OUT ($COUNT files, $SIZE)"
+echo "upload via the claude.ai skill UI"