diff --git a/scripts/bootstrap-common.sh b/scripts/bootstrap-common.sh
index 2ee8bf8..c4df644 100755
--- a/scripts/bootstrap-common.sh
+++ b/scripts/bootstrap-common.sh
@@ -17,7 +17,9 @@ set -euo pipefail
 # ── Constants ──────────────────────────────────────────────────────────
 FEE_DEST=0xf6a3eef9088A255c32b6aD2025f83E57291D9011
 WETH=0x4200000000000000000000000000000000000006
-SWAP_ROUTER=0x94cC0AaC535CCDB3C01d6787D6413C739ae12bc4
+SWAP_ROUTER_SEPOLIA=0x94cC0AaC535CCDB3C01d6787D6413C739ae12bc4
+SWAP_ROUTER_MAINNET=0x2626664c2603336E57B271c5C0b26F421741e481
+SWAP_ROUTER=""  # resolved lazily by detect_swap_router()
 MAX_UINT=0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
 
 DEFAULT_DEPLOYER_PK=0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80
@@ -39,6 +41,22 @@ bootstrap_log() {
 
 # ── Functions ──────────────────────────────────────────────────────────
 
+detect_swap_router() {
+  # Idempotency: only detect once
+  if [[ -n "$SWAP_ROUTER" ]]; then
+    return 0
+  fi
+  local chain_id
+  chain_id="$(cast chain-id --rpc-url "$ANVIL_RPC" 2>/dev/null || echo "")"
+  if [[ "$chain_id" == "8453" ]]; then
+    SWAP_ROUTER="$SWAP_ROUTER_MAINNET"
+    bootstrap_log "Detected Base mainnet (chain ID 8453) — using mainnet SwapRouter"
+  else
+    SWAP_ROUTER="$SWAP_ROUTER_SEPOLIA"
+    bootstrap_log "Using Base Sepolia SwapRouter (chain ID: ${chain_id:-unknown})"
+  fi
+}
+
 wait_for_rpc() {
   for _ in {1..120}; do
     if cast chain-id --rpc-url "$ANVIL_RPC" >/dev/null 2>&1; then
@@ -102,6 +120,7 @@ fund_liquidity_manager() {
 
 
 bootstrap_vwap() {
+  detect_swap_router
   # Idempotency guard: if a previous run already bootstrapped VWAP, skip.
   local cumvol
   cumvol="$(cast call --rpc-url "$ANVIL_RPC" \
@@ -169,6 +188,7 @@ bootstrap_vwap() {
 }
 
 seed_application_state() {
+  detect_swap_router
   bootstrap_log "Wrapping ETH to WETH"
   cast send --rpc-url "$ANVIL_RPC" --private-key "$DEPLOYER_PK" \
     "$WETH" "deposit()" --value 2ether >>"$LOG_FILE" 2>&1