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diff --git a/languages/typescript/githooks/pre-commit b/languages/typescript/githooks/pre-commit
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+++ b/languages/typescript/githooks/pre-commit
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+#!/usr/bin/env bash
+# Pre-commit hook: secret scan + syntax check on staged TypeScript/JavaScript files.
+# Use `git commit --no-verify` to bypass for confirmed false positives.
+
+set -u
+
+REPO_ROOT="$(git rev-parse --show-toplevel)"
+cd "$REPO_ROOT" || exit 1
+
+# --- 1. Secret scan ---
+# Patterns for common credentials. Scans only added lines in the staged diff.
+#
+# Two passes because case-sensitivity differs. AWS keys are uppercase, sk- keys
+# lowercase, PEM headers fixed, so those match case-SENSITIVELY: under -i,
+# AKIA[0-9A-Z]{16} matches any mixed-case 20-char run, which random base64 in an
+# embedded image blob hits ~6% of the time per 100KB and blocks real commits.
+# Only the keyword=value patterns need -i.
+SECRET_PATTERNS_CS='(AKIA[0-9A-Z]{16}|sk-[a-zA-Z0-9_-]{20,}|-----BEGIN (RSA|DSA|EC|OPENSSH|PGP)( PRIVATE)?( KEY| KEY BLOCK)?-----)'
+SECRET_PATTERNS_CI='(api[_-]?key|api[_-]?secret|auth[_-]?token|secret[_-]?key|bearer[_-]?token|access[_-]?token|password)[[:space:]]*[:=][[:space:]]*["'"'"'][^"'"'"']{16,}["'"'"']'
+
+added_lines="$(git diff --cached -U0 --diff-filter=AM \
+  | grep '^+' | grep -v '^+++' || true)"
+
+cs_hits="$(printf '%s\n' "$added_lines" | grep -nE  "$SECRET_PATTERNS_CS" || true)"
+ci_hits="$(printf '%s\n' "$added_lines" | grep -niE "$SECRET_PATTERNS_CI" || true)"
+# awk dedupes lines both passes matched, keeping first-seen order.
+secret_hits="$(printf '%s\n%s' "$cs_hits" "$ci_hits" \
+  | grep -v '^[[:space:]]*$' | awk '!seen[$0]++' || true)"
+
+if [ -n "$secret_hits" ]; then
+  echo "pre-commit: potential secret in staged changes:" >&2
+  echo "$secret_hits" >&2
+  echo "" >&2
+  echo "Review the lines above. If this is a false positive (test fixture, documentation)," >&2
+  echo "bypass with: git commit --no-verify" >&2
+  exit 1
+fi
+
+# --- 2. Syntax check on staged TS/JS files ---
+# Two checkers, because one tool can't do both jobs. `node --check` ignores
+# --experimental-strip-types, so on TypeScript it is wrong in BOTH directions:
+# it rejects valid TS (an `interface` reads as a syntax error) and accepts
+# broken TS. Measured on node v26.4.0, 2026-07-23. tsc is the only correct
+# parser for .ts; node is correct and much faster for .js.
+staged_js="$(git diff --cached --name-only --diff-filter=AM \
+  | grep -E '\.(js|jsx|mjs|cjs)$' || true)"
+staged_ts="$(git diff --cached --name-only --diff-filter=AM \
+  | grep -E '\.(ts|tsx|mts|cts)$' || true)"
+
+failed=""
+
+if [ -n "$staged_js" ] && command -v node >/dev/null 2>&1; then
+  while IFS= read -r f; do
+    [ -z "$f" ] && continue
+    [ -f "$f" ] || continue
+    if ! node --check "$f" >/dev/null 2>&1; then
+      failed="${failed}${f}"$'\n'
+    fi
+  done <<< "$staged_js"
+fi
+
+if [ -n "$staged_ts" ]; then
+  tsc_bin=""
+  if [ -x "./node_modules/.bin/tsc" ]; then
+    tsc_bin="./node_modules/.bin/tsc"
+  elif command -v tsc >/dev/null 2>&1; then
+    tsc_bin="tsc"
+  fi
+
+  if [ -n "$tsc_bin" ]; then
+    while IFS= read -r f; do
+      [ -z "$f" ] && continue
+      [ -f "$f" ] || continue
+      # Filter to TS1xxx, TypeScript's syntactic diagnostic range. TS2xxx and
+      # up are type errors, which need the whole project graph and are the
+      # build's job, not this hook's.
+      out="$("$tsc_bin" --noEmit --skipLibCheck --target es2022 \
+        --moduleDetection force "$f" 2>&1 || true)"
+      if printf '%s\n' "$out" | grep -qE 'error TS1[0-9]{3}:'; then
+        failed="${failed}${f}"$'\n'
+      fi
+    done <<< "$staged_ts"
+  fi
+fi
+
+if [ -n "$failed" ]; then
+  printf 'pre-commit: syntax errors in staged files:\n\n%s\n' "$failed" >&2
+  echo "Fix the parse errors above, then re-stage." >&2
+  exit 1
+fi
+
+exit 0