diff --git a/app/scripts/pg-backup.sh b/app/scripts/pg-backup.sh
new file mode 100644
index 0000000..cbd58d8
--- /dev/null
+++ b/app/scripts/pg-backup.sh
@@ -0,0 +1,39 @@
+#!/bin/sh
+# Teknav nightly Postgres backup.
+# Loops forever inside the postgres-backup container; uses a 24h sleep so the
+# host cron doesn't have to know anything. Runs once at startup, then every 24h.
+#
+# Output:    /backups/teknav-YYYYMMDD-HHMMSS.sql.gz
+# Retention: keep 14 days; older files auto-deleted.
+
+set -eu
+
+BACKUP_DIR="${BACKUP_DIR:-/backups}"
+RETENTION_DAYS="${BACKUP_RETENTION_DAYS:-14}"
+INTERVAL_SECONDS="${BACKUP_INTERVAL_SECONDS:-86400}"  # 24h
+
+mkdir -p "$BACKUP_DIR"
+
+run_once() {
+  ts="$(date -u +%Y%m%d-%H%M%S)"
+  out="${BACKUP_DIR}/teknav-${ts}.sql.gz"
+  echo "[pg-backup] dumping → ${out}"
+  PGPASSWORD="${POSTGRES_PASSWORD}" pg_dump \
+      --host=postgres \
+      --username="${POSTGRES_USER}" \
+      --dbname="${POSTGRES_DB}" \
+      --no-owner --no-privileges \
+      --format=plain \
+    | gzip -9 > "$out.tmp" \
+    && mv "$out.tmp" "$out"
+  echo "[pg-backup] done → $(du -h "$out" | cut -f1)"
+
+  echo "[pg-backup] pruning files older than ${RETENTION_DAYS} days"
+  find "$BACKUP_DIR" -maxdepth 1 -name 'teknav-*.sql.gz' -type f -mtime +"$RETENTION_DAYS" -print -delete || true
+}
+
+while true; do
+  run_once || echo "[pg-backup] dump failed; will retry next cycle"
+  echo "[pg-backup] sleeping ${INTERVAL_SECONDS}s"
+  sleep "$INTERVAL_SECONDS"
+done