diff --git a/scripts/validation/validate-xdc-zero-relayer-env.sh b/scripts/validation/validate-xdc-zero-relayer-env.sh
new file mode 100755
index 0000000..fde7b31
--- /dev/null
+++ b/scripts/validation/validate-xdc-zero-relayer-env.sh
@@ -0,0 +1,62 @@
+#!/usr/bin/env bash
+# Validate XDC Zero relayer env/default example files for key presence and drift.
+# Usage: bash scripts/validation/validate-xdc-zero-relayer-env.sh
+
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+PROJECT_ROOT="$(cd "$SCRIPT_DIR/../.." && pwd)"
+
+DOTENV_FILE="$PROJECT_ROOT/config/xdc-zero/xdc-relayer.dotenv.example"
+PAIR_ENV_FILE="$PROJECT_ROOT/config/xdc-zero/xdc-zero-chain138-pair.example.env"
+DEFAULTS_FILE="$PROJECT_ROOT/config/xdc-zero/xdc-zero-relayer-138-pair.example.defaults"
+SERVICE_FILE="$PROJECT_ROOT/config/systemd/xdc-zero-relayer-138-pair.example.service"
+
+for f in "$DOTENV_FILE" "$PAIR_ENV_FILE" "$DEFAULTS_FILE" "$SERVICE_FILE"; do
+  [[ -f "$f" ]] || { echo "ERROR: missing file: $f" >&2; exit 1; }
+done
+
+require_key() {
+  local file="$1"
+  local key="$2"
+  if ! grep -qE "^${key}=" "$file"; then
+    echo "ERROR: missing ${key}= in $file" >&2
+    exit 1
+  fi
+}
+
+value_for() {
+  local file="$1"
+  local key="$2"
+  sed -n "s/^${key}=//p" "$file" | head -n 1
+}
+
+for key in RELAYER_PORT NODE_ENV SUBNET_URL PARENTNET_URL CHECKPOINT_CONTRACT MAX_FETCH_BLOCK_SIZE; do
+  require_key "$DOTENV_FILE" "$key"
+  require_key "$DEFAULTS_FILE" "$key"
+done
+
+for key in XDC_PARENTNET_URL RPC_URL_138 PARENTNET_URL SUBNET_URL CHECKPOINT_CONTRACT_138_ON_PARENT REVERSE_CHECKPOINT_CONTRACT_PARENT_ON_138; do
+  require_key "$PAIR_ENV_FILE" "$key"
+done
+
+for key in RELAYER_PORT NODE_ENV PARENTNET_URL SUBNET_URL MAX_FETCH_BLOCK_SIZE; do
+  v1="$(value_for "$DOTENV_FILE" "$key")"
+  v2="$(value_for "$DEFAULTS_FILE" "$key")"
+  if [[ "$v1" != "$v2" ]]; then
+    echo "ERROR: drift for $key between $(basename "$DOTENV_FILE") and $(basename "$DEFAULTS_FILE"): '$v1' != '$v2'" >&2
+    exit 1
+  fi
+done
+
+if ! grep -qF 'xdc-zero-relayer-138-pair.example.defaults' "$SERVICE_FILE"; then
+  echo "ERROR: systemd example should reference xdc-zero-relayer-138-pair.example.defaults" >&2
+  exit 1
+fi
+
+if ! grep -qE 'xdc-relayer\.dotenv\.example.*clone-local' "$PROJECT_ROOT/config/xdc-zero/README.md"; then
+  echo "ERROR: config/xdc-zero/README.md should describe clone-local use of xdc-relayer.dotenv.example" >&2
+  exit 1
+fi
+
+echo "[OK] XDC Zero relayer env/default examples are aligned"