diff --git a/tests/scripts.bats b/tests/scripts.bats
new file mode 100644
index 0000000..5b7fe1b
--- /dev/null
+++ b/tests/scripts.bats
@@ -0,0 +1,53 @@
+#!/usr/bin/env bats
+# tests/scripts.bats — unit tests for the deterministic skill scripts.
+load helpers
+
+@test "slug: path with extension and spaces" {
+  run bash "$SKILL_SCRIPTS/slug.sh" "raw/articles/My Test Source.md"
+  [ "$status" -eq 0 ]
+  [ "$output" = "my-test-source" ]
+}
+
+@test "slug: punctuation and repeats collapse to single hyphens" {
+  run bash "$SKILL_SCRIPTS/slug.sh" "Qualche  Concetto!! Strano"
+  [ "$output" = "qualche-concetto-strano" ]
+}
+
+@test "log-append: appends a well-formed INGEST entry with a run_id" {
+  G="$(make_fixture_genome)"; cd "$G"
+  run bash "$SKILL_SCRIPTS/log-append.sh" --type INGEST --subject foo --model m \
+    --context "[[raw/x]]" --output "[[sources/foo]]" --reasoning "why"
+  [ "$status" -eq 0 ]
+  grep -q "INGEST | foo" wiki/log.md
+  grep -q '^- run_id: `' wiki/log.md
+  grep -q '^- model: `m`' wiki/log.md
+}
+
+@test "log-append: rejects an invalid TYPE" {
+  G="$(make_fixture_genome)"; cd "$G"
+  run bash "$SKILL_SCRIPTS/log-append.sh" --type BOGUS --subject foo
+  [ "$status" -ne 0 ]
+}
+
+@test "index-append: inserts under the right section and keeps it sorted" {
+  G="$(make_fixture_genome)"; cd "$G"
+  python3 "$SKILL_SCRIPTS/index-append.py" --section Sources --entry '- [[sources/zzz]] — z. `maturity: draft`'
+  python3 "$SKILL_SCRIPTS/index-append.py" --section Sources --entry '- [[sources/aaa]] — a. `maturity: draft`'
+  a=$(grep -n 'sources/aaa' wiki/index.md | cut -d: -f1)
+  z=$(grep -n 'sources/zzz' wiki/index.md | cut -d: -f1)
+  [ -n "$a" ] && [ -n "$z" ]
+  [ "$a" -lt "$z" ]
+}
+
+@test "index-append: bumps frontmatter last_updated to today" {
+  G="$(make_fixture_genome)"; cd "$G"
+  python3 "$SKILL_SCRIPTS/index-append.py" --section Concepts --entry '- [[concepts/x]] — x. `maturity: draft`'
+  grep -q "^last_updated: $(date +%F)$" wiki/index.md
+}
+
+@test "index-append: is idempotent for the same entry" {
+  G="$(make_fixture_genome)"; cd "$G"
+  python3 "$SKILL_SCRIPTS/index-append.py" --section Sources --entry '- [[sources/dup]] — d. `maturity: draft`'
+  python3 "$SKILL_SCRIPTS/index-append.py" --section Sources --entry '- [[sources/dup]] — d. `maturity: draft`'
+  [ "$(grep -c 'sources/dup' wiki/index.md)" -eq 1 ]
+}