diff --git a/bin/hermit.hcl b/bin/hermit.hcl
index e69de29b..624421a0 100644
--- a/bin/hermit.hcl
+++ b/bin/hermit.hcl
@@ -0,0 +1 @@
+sources = ["https://github.com/TBD54566975/hermit-ftl.git", "https://github.com/cashapp/hermit-packages.git"]
diff --git a/frontend/mobile/lib/api/ad.dart b/frontend/mobile/lib/api/ad.dart
index 2faa38bc..4721e4aa 100644
--- a/frontend/mobile/lib/api/ad.dart
+++ b/frontend/mobile/lib/api/ad.dart
@@ -8,11 +8,11 @@ import 'ftl_client.dart';
 class AdRequest {
   List<String> contextKeys;
 
-  AdRequest({ required this.contextKeys,  });
+  AdRequest({  required this.contextKeys,  });
 
   Map<String, dynamic> toMap() {
     return {
-      'contextKeys': ((dynamic v) =>v.map((v) => v).cast<String>().toList())(contextKeys),
+      'contextKeys': ((dynamic v) => v.map((v) => v).cast<String>().toList())(contextKeys),
     };
   }
 
@@ -31,12 +31,12 @@ class Ad {
   String redirectURL;
   String text;
 
-  Ad({ required this.redirectURL, required this.text,  });
+  Ad({  required this.redirectURL,  required this.text,  });
 
   Map<String, dynamic> toMap() {
     return {
-      'redirectURL': ((dynamic v) =>v)(redirectURL),
-      'text': ((dynamic v) =>v)(text),
+      'redirectURL': ((dynamic v) => v)(redirectURL),
+      'text': ((dynamic v) => v)(text),
     };
   }
 
@@ -56,12 +56,12 @@ class AdResponse {
   String name;
   List<Ad> ads;
 
-  AdResponse({ required this.name, required this.ads,  });
+  AdResponse({  required this.name,  required this.ads,  });
 
   Map<String, dynamic> toMap() {
     return {
-      'name': ((dynamic v) =>v)(name),
-      'ads': ((dynamic v) =>v.map((v) => Ad.fromMap(v)).cast<Ad>().toList())(ads),
+      'name': ((dynamic v) => v)(name),
+      'ads': ((dynamic v) => v.map((v) => Ad.fromMap(v)).cast<Ad>().toList())(ads),
     };
   }
 
@@ -85,7 +85,7 @@ class AdClient {
 
 
   Future<AdResponse> get(AdRequest request) async {
-    final response = await ftlClient.get('/ad', request: request.toMap());
+    final response = await ftlClient.get('/ad', requestJson: request.toJson());
     if (response.statusCode == 200) {
       return AdResponse.fromJson(response.body);
     } else {
diff --git a/frontend/mobile/lib/api/cart.dart b/frontend/mobile/lib/api/cart.dart
index 8608fbb2..5890e88c 100644
--- a/frontend/mobile/lib/api/cart.dart
+++ b/frontend/mobile/lib/api/cart.dart
@@ -9,12 +9,12 @@ class Item {
   String productID;
   int quantity;
 
-  Item({ required this.productID, required this.quantity,  });
+  Item({  required this.productID,  required this.quantity,  });
 
   Map<String, dynamic> toMap() {
     return {
-      'productID': ((dynamic v) =>v)(productID),
-      'quantity': ((dynamic v) =>v)(quantity),
+      'productID': ((dynamic v) => v)(productID),
+      'quantity': ((dynamic v) => v)(quantity),
     };
   }
 
@@ -34,12 +34,12 @@ class AddItemRequest {
   String userID;
   Item item;
 
-  AddItemRequest({ required this.userID, required this.item,  });
+  AddItemRequest({  required this.userID,  required this.item,  });
 
   Map<String, dynamic> toMap() {
     return {
-      'userID': ((dynamic v) =>v)(userID),
-      'item': ((dynamic v) =>v.toMap())(item),
+      'userID': ((dynamic v) => v)(userID),
+      'item': ((dynamic v) => v.toMap())(item),
     };
   }
 
@@ -77,11 +77,11 @@ class AddItemResponse {
 class GetCartRequest {
   String userID;
 
-  GetCartRequest({ required this.userID,  });
+  GetCartRequest({  required this.userID,  });
 
   Map<String, dynamic> toMap() {
     return {
-      'userID': ((dynamic v) =>v)(userID),
+      'userID': ((dynamic v) => v)(userID),
     };
   }
 
@@ -100,12 +100,12 @@ class Cart {
   String userID;
   List<Item> items;
 
-  Cart({ required this.userID, required this.items,  });
+  Cart({  required this.userID,  required this.items,  });
 
   Map<String, dynamic> toMap() {
     return {
-      'userID': ((dynamic v) =>v)(userID),
-      'items': ((dynamic v) =>v.map((v) => Item.fromMap(v)).cast<Item>().toList())(items),
+      'userID': ((dynamic v) => v)(userID),
+      'items': ((dynamic v) => v.map((v) => Item.fromMap(v)).cast<Item>().toList())(items),
     };
   }
 
@@ -124,11 +124,11 @@ class Cart {
 class EmptyCartRequest {
   String userID;
 
-  EmptyCartRequest({ required this.userID,  });
+  EmptyCartRequest({  required this.userID,  });
 
   Map<String, dynamic> toMap() {
     return {
-      'userID': ((dynamic v) =>v)(userID),
+      'userID': ((dynamic v) => v)(userID),
     };
   }
 
@@ -179,7 +179,7 @@ class CartClient {
   }
 
   Future<Cart> getCart(GetCartRequest request) async {
-    final response = await ftlClient.get('/cart', request: request.toMap());
+    final response = await ftlClient.get('/cart', requestJson: request.toJson());
     if (response.statusCode == 200) {
       return Cart.fromJson(response.body);
     } else {
diff --git a/frontend/mobile/lib/api/checkout.dart b/frontend/mobile/lib/api/checkout.dart
index fb0fee9f..99dc9a7b 100644
--- a/frontend/mobile/lib/api/checkout.dart
+++ b/frontend/mobile/lib/api/checkout.dart
@@ -3,94 +3,29 @@ library checkout;
 
 import 'dart:convert';
 import 'ftl_client.dart';
-import 'productcatalog.dart' as productcatalog;
-import 'currency.dart' as currency;
 import 'shipping.dart' as shipping;
 import 'payment.dart' as payment;
 import 'cart.dart' as cart;
+import 'currency.dart' as currency;
+import 'productcatalog.dart' as productcatalog;
 
 
-class Address {
-  String streetAddress;
-  String city;
-  String state;
-  String country;
-  int zipCode;
-
-  Address({ required this.streetAddress, required this.city, required this.state, required this.country, required this.zipCode,  });
-
-  Map<String, dynamic> toMap() {
-    return {
-      'streetAddress': ((dynamic v) =>v)(streetAddress),
-      'city': ((dynamic v) =>v)(city),
-      'state': ((dynamic v) =>v)(state),
-      'country': ((dynamic v) =>v)(country),
-      'zipCode': ((dynamic v) =>v)(zipCode),
-    };
-  }
-
-  factory Address.fromMap(Map<String, dynamic> map) {
-    return Address(
-      streetAddress: ((dynamic v) => v)(map['streetAddress']),
-      city: ((dynamic v) => v)(map['city']),
-      state: ((dynamic v) => v)(map['state']),
-      country: ((dynamic v) => v)(map['country']),
-      zipCode: ((dynamic v) => v)(map['zipCode']),
-    );
-  }
-
-  String toJson() => json.encode(toMap());
-
-  factory Address.fromJson(String source) => Address.fromMap(json.decode(source));
-}
-
-class CreditCardInfo {
-  String number;
-  int cVV;
-  int expirationYear;
-  int expirationMonth;
-
-  CreditCardInfo({ required this.number, required this.cVV, required this.expirationYear, required this.expirationMonth,  });
-
-  Map<String, dynamic> toMap() {
-    return {
-      'number': ((dynamic v) =>v)(number),
-      'cVV': ((dynamic v) =>v)(cVV),
-      'expirationYear': ((dynamic v) =>v)(expirationYear),
-      'expirationMonth': ((dynamic v) =>v)(expirationMonth),
-    };
-  }
-
-  factory CreditCardInfo.fromMap(Map<String, dynamic> map) {
-    return CreditCardInfo(
-      number: ((dynamic v) => v)(map['number']),
-      cVV: ((dynamic v) => v)(map['cVV']),
-      expirationYear: ((dynamic v) => v)(map['expirationYear']),
-      expirationMonth: ((dynamic v) => v)(map['expirationMonth']),
-    );
-  }
-
-  String toJson() => json.encode(toMap());
-
-  factory CreditCardInfo.fromJson(String source) => CreditCardInfo.fromMap(json.decode(source));
-}
-
 class PlaceOrderRequest {
   String userID;
   String userCurrency;
-  Address address;
+  shipping.Address address;
   String email;
-  CreditCardInfo creditCard;
+  payment.CreditCardInfo creditCard;
 
-  PlaceOrderRequest({ required this.userID, required this.userCurrency, required this.address, required this.email, required this.creditCard,  });
+  PlaceOrderRequest({  required this.userID,  required this.userCurrency,  required this.address,  required this.email,  required this.creditCard,  });
 
   Map<String, dynamic> toMap() {
     return {
-      'userID': ((dynamic v) =>v)(userID),
-      'userCurrency': ((dynamic v) =>v)(userCurrency),
-      'address': ((dynamic v) =>v.toMap())(address),
-      'email': ((dynamic v) =>v)(email),
-      'creditCard': ((dynamic v) =>v.toMap())(creditCard),
+      'userID': ((dynamic v) => v)(userID),
+      'userCurrency': ((dynamic v) => v)(userCurrency),
+      'address': ((dynamic v) => v.toMap())(address),
+      'email': ((dynamic v) => v)(email),
+      'creditCard': ((dynamic v) => v.toMap())(creditCard),
     };
   }
 
@@ -98,9 +33,9 @@ class PlaceOrderRequest {
     return PlaceOrderRequest(
       userID: ((dynamic v) => v)(map['userID']),
       userCurrency: ((dynamic v) => v)(map['userCurrency']),
-      address: ((dynamic v) => Address.fromMap(v))(map['address']),
+      address: ((dynamic v) => shipping.Address.fromMap(v))(map['address']),
       email: ((dynamic v) => v)(map['email']),
-      creditCard: ((dynamic v) => CreditCardInfo.fromMap(v))(map['creditCard']),
+      creditCard: ((dynamic v) => payment.CreditCardInfo.fromMap(v))(map['creditCard']),
     );
   }
 
@@ -109,76 +44,23 @@ class PlaceOrderRequest {
   factory PlaceOrderRequest.fromJson(String source) => PlaceOrderRequest.fromMap(json.decode(source));
 }
 
-class Money {
-  String currencyCode;
-  int units;
-  int nanos;
-
-  Money({ required this.currencyCode, required this.units, required this.nanos,  });
-
-  Map<String, dynamic> toMap() {
-    return {
-      'currencyCode': ((dynamic v) =>v)(currencyCode),
-      'units': ((dynamic v) =>v)(units),
-      'nanos': ((dynamic v) =>v)(nanos),
-    };
-  }
-
-  factory Money.fromMap(Map<String, dynamic> map) {
-    return Money(
-      currencyCode: ((dynamic v) => v)(map['currencyCode']),
-      units: ((dynamic v) => v)(map['units']),
-      nanos: ((dynamic v) => v)(map['nanos']),
-    );
-  }
-
-  String toJson() => json.encode(toMap());
-
-  factory Money.fromJson(String source) => Money.fromMap(json.decode(source));
-}
-
-class Item {
-  String productID;
-  int quantity;
-
-  Item({ required this.productID, required this.quantity,  });
-
-  Map<String, dynamic> toMap() {
-    return {
-      'productID': ((dynamic v) =>v)(productID),
-      'quantity': ((dynamic v) =>v)(quantity),
-    };
-  }
-
-  factory Item.fromMap(Map<String, dynamic> map) {
-    return Item(
-      productID: ((dynamic v) => v)(map['productID']),
-      quantity: ((dynamic v) => v)(map['quantity']),
-    );
-  }
-
-  String toJson() => json.encode(toMap());
-
-  factory Item.fromJson(String source) => Item.fromMap(json.decode(source));
-}
-
 class OrderItem {
-  Item item;
-  Money cost;
+  cart.Item item;
+  currency.Money cost;
 
-  OrderItem({ required this.item, required this.cost,  });
+  OrderItem({  required this.item,  required this.cost,  });
 
   Map<String, dynamic> toMap() {
     return {
-      'item': ((dynamic v) =>v.toMap())(item),
-      'cost': ((dynamic v) =>v.toMap())(cost),
+      'item': ((dynamic v) => v.toMap())(item),
+      'cost': ((dynamic v) => v.toMap())(cost),
     };
   }
 
   factory OrderItem.fromMap(Map<String, dynamic> map) {
     return OrderItem(
-      item: ((dynamic v) => Item.fromMap(v))(map['item']),
-      cost: ((dynamic v) => Money.fromMap(v))(map['cost']),
+      item: ((dynamic v) => cart.Item.fromMap(v))(map['item']),
+      cost: ((dynamic v) => currency.Money.fromMap(v))(map['cost']),
     );
   }
 
@@ -190,19 +72,19 @@ class OrderItem {
 class Order {
   String id;
   String shippingTrackingID;
-  Money shippingCost;
-  Address shippingAddress;
+  currency.Money shippingCost;
+  shipping.Address shippingAddress;
   List<OrderItem> items;
 
-  Order({ required this.id, required this.shippingTrackingID, required this.shippingCost, required this.shippingAddress, required this.items,  });
+  Order({  required this.id,  required this.shippingTrackingID,  required this.shippingCost,  required this.shippingAddress,  required this.items,  });
 
   Map<String, dynamic> toMap() {
     return {
-      'id': ((dynamic v) =>v)(id),
-      'shippingTrackingID': ((dynamic v) =>v)(shippingTrackingID),
-      'shippingCost': ((dynamic v) =>v.toMap())(shippingCost),
-      'shippingAddress': ((dynamic v) =>v.toMap())(shippingAddress),
-      'items': ((dynamic v) =>v.map((v) => OrderItem.fromMap(v)).cast<OrderItem>().toList())(items),
+      'id': ((dynamic v) => v)(id),
+      'shippingTrackingID': ((dynamic v) => v)(shippingTrackingID),
+      'shippingCost': ((dynamic v) => v.toMap())(shippingCost),
+      'shippingAddress': ((dynamic v) => v.toMap())(shippingAddress),
+      'items': ((dynamic v) => v.map((v) => OrderItem.fromMap(v)).cast<OrderItem>().toList())(items),
     };
   }
 
@@ -210,8 +92,8 @@ class Order {
     return Order(
       id: ((dynamic v) => v)(map['id']),
       shippingTrackingID: ((dynamic v) => v)(map['shippingTrackingID']),
-      shippingCost: ((dynamic v) => Money.fromMap(v))(map['shippingCost']),
-      shippingAddress: ((dynamic v) => Address.fromMap(v))(map['shippingAddress']),
+      shippingCost: ((dynamic v) => currency.Money.fromMap(v))(map['shippingCost']),
+      shippingAddress: ((dynamic v) => shipping.Address.fromMap(v))(map['shippingAddress']),
       items: ((dynamic v) => v.map((v) => OrderItem.fromMap(v)).cast<OrderItem>().toList())(map['items']),
     );
   }
@@ -229,7 +111,7 @@ class CheckoutClient {
 
 
   Future<Order> placeOrder(PlaceOrderRequest request) async {
-    final response = await ftlClient.post('/checkout', request: request.toMap());
+    final response = await ftlClient.post('/checkout/${request.userID}', request: request.toMap());
     if (response.statusCode == 200) {
       return Order.fromJson(response.body);
     } else {
diff --git a/frontend/mobile/lib/api/currency.dart b/frontend/mobile/lib/api/currency.dart
index 5b0f6add..6175e7f6 100644
--- a/frontend/mobile/lib/api/currency.dart
+++ b/frontend/mobile/lib/api/currency.dart
@@ -27,11 +27,11 @@ class GetSupportedCurrenciesRequest {
 class GetSupportedCurrenciesResponse {
   List<String> currencyCodes;
 
-  GetSupportedCurrenciesResponse({ required this.currencyCodes,  });
+  GetSupportedCurrenciesResponse({  required this.currencyCodes,  });
 
   Map<String, dynamic> toMap() {
     return {
-      'currencyCodes': ((dynamic v) =>v.map((v) => v).cast<String>().toList())(currencyCodes),
+      'currencyCodes': ((dynamic v) => v.map((v) => v).cast<String>().toList())(currencyCodes),
     };
   }
 
@@ -51,13 +51,13 @@ class Money {
   int units;
   int nanos;
 
-  Money({ required this.currencyCode, required this.units, required this.nanos,  });
+  Money({  required this.currencyCode,  required this.units,  required this.nanos,  });
 
   Map<String, dynamic> toMap() {
     return {
-      'currencyCode': ((dynamic v) =>v)(currencyCode),
-      'units': ((dynamic v) =>v)(units),
-      'nanos': ((dynamic v) =>v)(nanos),
+      'currencyCode': ((dynamic v) => v)(currencyCode),
+      'units': ((dynamic v) => v)(units),
+      'nanos': ((dynamic v) => v)(nanos),
     };
   }
 
@@ -78,12 +78,12 @@ class ConvertRequest {
   Money from;
   String toCode;
 
-  ConvertRequest({ required this.from, required this.toCode,  });
+  ConvertRequest({  required this.from,  required this.toCode,  });
 
   Map<String, dynamic> toMap() {
     return {
-      'from': ((dynamic v) =>v.toMap())(from),
-      'toCode': ((dynamic v) =>v)(toCode),
+      'from': ((dynamic v) => v.toMap())(from),
+      'toCode': ((dynamic v) => v)(toCode),
     };
   }
 
@@ -107,7 +107,7 @@ class CurrencyClient {
 
 
   Future<GetSupportedCurrenciesResponse> getSupportedCurrencies(GetSupportedCurrenciesRequest request) async {
-    final response = await ftlClient.get('/currency/supported', request: request.toMap());
+    final response = await ftlClient.get('/currency/supported', requestJson: request.toJson());
     if (response.statusCode == 200) {
       return GetSupportedCurrenciesResponse.fromJson(response.body);
     } else {
diff --git a/frontend/mobile/lib/api/ftl_client.dart b/frontend/mobile/lib/api/ftl_client.dart
index f93b686b..3ce3a52f 100644
--- a/frontend/mobile/lib/api/ftl_client.dart
+++ b/frontend/mobile/lib/api/ftl_client.dart
@@ -21,14 +21,14 @@ class FTLHttpClient {
 
   Future<http.Response> get(
     String path, {
-    Map<String, dynamic>? request,
+    String? requestJson,
     Map<String, String>? headers,
   }) {
     Uri uri;
-    if (request == null || request.isEmpty) {
+    if (requestJson == null || requestJson.isEmpty) {
       uri = Uri.http("localhost:8892", '/ingress$path');
     } else {
-      uri = Uri.http("localhost:8892", '/ingress$path', request);
+      uri = Uri.http("localhost:8892", '/ingress$path', {'@json': requestJson});
     }
     return httpClient.get(uri, headers: headers);
   }
diff --git a/frontend/mobile/lib/api/payment.dart b/frontend/mobile/lib/api/payment.dart
index c6a35bdf..d4d6388f 100644
--- a/frontend/mobile/lib/api/payment.dart
+++ b/frontend/mobile/lib/api/payment.dart
@@ -3,50 +3,23 @@ library payment;
 
 import 'dart:convert';
 import 'ftl_client.dart';
+import 'currency.dart' as currency;
 
 
-class Money {
-  String currencyCode;
-  int units;
-  int nanos;
-
-  Money({ required this.currencyCode, required this.units, required this.nanos,  });
-
-  Map<String, dynamic> toMap() {
-    return {
-      'currencyCode': ((dynamic v) =>v)(currencyCode),
-      'units': ((dynamic v) =>v)(units),
-      'nanos': ((dynamic v) =>v)(nanos),
-    };
-  }
-
-  factory Money.fromMap(Map<String, dynamic> map) {
-    return Money(
-      currencyCode: ((dynamic v) => v)(map['currencyCode']),
-      units: ((dynamic v) => v)(map['units']),
-      nanos: ((dynamic v) => v)(map['nanos']),
-    );
-  }
-
-  String toJson() => json.encode(toMap());
-
-  factory Money.fromJson(String source) => Money.fromMap(json.decode(source));
-}
-
 class CreditCardInfo {
   String number;
   int cVV;
   int expirationYear;
   int expirationMonth;
 
-  CreditCardInfo({ required this.number, required this.cVV, required this.expirationYear, required this.expirationMonth,  });
+  CreditCardInfo({  required this.number,  required this.cVV,  required this.expirationYear,  required this.expirationMonth,  });
 
   Map<String, dynamic> toMap() {
     return {
-      'number': ((dynamic v) =>v)(number),
-      'cVV': ((dynamic v) =>v)(cVV),
-      'expirationYear': ((dynamic v) =>v)(expirationYear),
-      'expirationMonth': ((dynamic v) =>v)(expirationMonth),
+      'number': ((dynamic v) => v)(number),
+      'cVV': ((dynamic v) => v)(cVV),
+      'expirationYear': ((dynamic v) => v)(expirationYear),
+      'expirationMonth': ((dynamic v) => v)(expirationMonth),
     };
   }
 
@@ -65,21 +38,21 @@ class CreditCardInfo {
 }
 
 class ChargeRequest {
-  Money amount;
+  currency.Money amount;
   CreditCardInfo creditCard;
 
-  ChargeRequest({ required this.amount, required this.creditCard,  });
+  ChargeRequest({  required this.amount,  required this.creditCard,  });
 
   Map<String, dynamic> toMap() {
     return {
-      'amount': ((dynamic v) =>v.toMap())(amount),
-      'creditCard': ((dynamic v) =>v.toMap())(creditCard),
+      'amount': ((dynamic v) => v.toMap())(amount),
+      'creditCard': ((dynamic v) => v.toMap())(creditCard),
     };
   }
 
   factory ChargeRequest.fromMap(Map<String, dynamic> map) {
     return ChargeRequest(
-      amount: ((dynamic v) => Money.fromMap(v))(map['amount']),
+      amount: ((dynamic v) => currency.Money.fromMap(v))(map['amount']),
       creditCard: ((dynamic v) => CreditCardInfo.fromMap(v))(map['creditCard']),
     );
   }
@@ -92,11 +65,11 @@ class ChargeRequest {
 class ChargeResponse {
   String transactionID;
 
-  ChargeResponse({ required this.transactionID,  });
+  ChargeResponse({  required this.transactionID,  });
 
   Map<String, dynamic> toMap() {
     return {
-      'transactionID': ((dynamic v) =>v)(transactionID),
+      'transactionID': ((dynamic v) => v)(transactionID),
     };
   }
 
diff --git a/frontend/mobile/lib/api/productcatalog.dart b/frontend/mobile/lib/api/productcatalog.dart
index a9b56c5a..b799ab66 100644
--- a/frontend/mobile/lib/api/productcatalog.dart
+++ b/frontend/mobile/lib/api/productcatalog.dart
@@ -3,6 +3,7 @@ library productcatalog;
 
 import 'dart:convert';
 import 'ftl_client.dart';
+import 'currency.dart' as currency;
 
 
 class ListRequest {
@@ -24,52 +25,24 @@ class ListRequest {
   factory ListRequest.fromJson(String source) => ListRequest.fromMap(json.decode(source));
 }
 
-class Money {
-  String currencyCode;
-  int units;
-  int nanos;
-
-  Money({ required this.currencyCode, required this.units, required this.nanos,  });
-
-  Map<String, dynamic> toMap() {
-    return {
-      'currencyCode': ((dynamic v) =>v)(currencyCode),
-      'units': ((dynamic v) =>v)(units),
-      'nanos': ((dynamic v) =>v)(nanos),
-    };
-  }
-
-  factory Money.fromMap(Map<String, dynamic> map) {
-    return Money(
-      currencyCode: ((dynamic v) => v)(map['currencyCode']),
-      units: ((dynamic v) => v)(map['units']),
-      nanos: ((dynamic v) => v)(map['nanos']),
-    );
-  }
-
-  String toJson() => json.encode(toMap());
-
-  factory Money.fromJson(String source) => Money.fromMap(json.decode(source));
-}
-
 class Product {
   String id;
   String name;
   String description;
   String picture;
-  Money priceUSD;
+  currency.Money priceUSD;
   List<String> categories;
 
-  Product({ required this.id, required this.name, required this.description, required this.picture, required this.priceUSD, required this.categories,  });
+  Product({  required this.id,  required this.name,  required this.description,  required this.picture,  required this.priceUSD,  required this.categories,  });
 
   Map<String, dynamic> toMap() {
     return {
-      'id': ((dynamic v) =>v)(id),
-      'name': ((dynamic v) =>v)(name),
-      'description': ((dynamic v) =>v)(description),
-      'picture': ((dynamic v) =>v)(picture),
-      'priceUSD': ((dynamic v) =>v.toMap())(priceUSD),
-      'categories': ((dynamic v) =>v.map((v) => v).cast<String>().toList())(categories),
+      'id': ((dynamic v) => v)(id),
+      'name': ((dynamic v) => v)(name),
+      'description': ((dynamic v) => v)(description),
+      'picture': ((dynamic v) => v)(picture),
+      'priceUSD': ((dynamic v) => v.toMap())(priceUSD),
+      'categories': ((dynamic v) => v.map((v) => v).cast<String>().toList())(categories),
     };
   }
 
@@ -79,7 +52,7 @@ class Product {
       name: ((dynamic v) => v)(map['name']),
       description: ((dynamic v) => v)(map['description']),
       picture: ((dynamic v) => v)(map['picture']),
-      priceUSD: ((dynamic v) => Money.fromMap(v))(map['priceUSD']),
+      priceUSD: ((dynamic v) => currency.Money.fromMap(v))(map['priceUSD']),
       categories: ((dynamic v) => v.map((v) => v).cast<String>().toList())(map['categories']),
     );
   }
@@ -92,11 +65,11 @@ class Product {
 class ListResponse {
   List<Product> products;
 
-  ListResponse({ required this.products,  });
+  ListResponse({  required this.products,  });
 
   Map<String, dynamic> toMap() {
     return {
-      'products': ((dynamic v) =>v.map((v) => Product.fromMap(v)).cast<Product>().toList())(products),
+      'products': ((dynamic v) => v.map((v) => Product.fromMap(v)).cast<Product>().toList())(products),
     };
   }
 
@@ -114,11 +87,11 @@ class ListResponse {
 class GetRequest {
   String id;
 
-  GetRequest({ required this.id,  });
+  GetRequest({  required this.id,  });
 
   Map<String, dynamic> toMap() {
     return {
-      'id': ((dynamic v) =>v)(id),
+      'id': ((dynamic v) => v)(id),
     };
   }
 
@@ -136,11 +109,11 @@ class GetRequest {
 class SearchRequest {
   String query;
 
-  SearchRequest({ required this.query,  });
+  SearchRequest({  required this.query,  });
 
   Map<String, dynamic> toMap() {
     return {
-      'query': ((dynamic v) =>v)(query),
+      'query': ((dynamic v) => v)(query),
     };
   }
 
@@ -158,11 +131,11 @@ class SearchRequest {
 class SearchResponse {
   List<Product> results;
 
-  SearchResponse({ required this.results,  });
+  SearchResponse({  required this.results,  });
 
   Map<String, dynamic> toMap() {
     return {
-      'results': ((dynamic v) =>v.map((v) => Product.fromMap(v)).cast<Product>().toList())(results),
+      'results': ((dynamic v) => v.map((v) => Product.fromMap(v)).cast<Product>().toList())(results),
     };
   }
 
@@ -185,7 +158,7 @@ class ProductcatalogClient {
 
 
   Future<ListResponse> list(ListRequest request) async {
-    final response = await ftlClient.get('/productcatalog', request: request.toMap());
+    final response = await ftlClient.get('/productcatalog', requestJson: request.toJson());
     if (response.statusCode == 200) {
       return ListResponse.fromJson(response.body);
     } else {
@@ -194,7 +167,7 @@ class ProductcatalogClient {
   }
 
   Future<Product> get(GetRequest request) async {
-    final response = await ftlClient.get('/productcatalog/id', request: request.toMap());
+    final response = await ftlClient.get('/productcatalog/${request.id}', requestJson: request.toJson());
     if (response.statusCode == 200) {
       return Product.fromJson(response.body);
     } else {
diff --git a/frontend/mobile/lib/api/recommendation.dart b/frontend/mobile/lib/api/recommendation.dart
index fed4e74f..7cec7332 100644
--- a/frontend/mobile/lib/api/recommendation.dart
+++ b/frontend/mobile/lib/api/recommendation.dart
@@ -10,12 +10,12 @@ class ListRequest {
   String userID;
   List<String> userProductIDs;
 
-  ListRequest({ required this.userID, required this.userProductIDs,  });
+  ListRequest({  required this.userID,  required this.userProductIDs,  });
 
   Map<String, dynamic> toMap() {
     return {
-      'userID': ((dynamic v) =>v)(userID),
-      'userProductIDs': ((dynamic v) =>v.map((v) => v).cast<String>().toList())(userProductIDs),
+      'userID': ((dynamic v) => v)(userID),
+      'userProductIDs': ((dynamic v) => v.map((v) => v).cast<String>().toList())(userProductIDs),
     };
   }
 
@@ -34,11 +34,11 @@ class ListRequest {
 class ListResponse {
   List<String> productIDs;
 
-  ListResponse({ required this.productIDs,  });
+  ListResponse({  required this.productIDs,  });
 
   Map<String, dynamic> toMap() {
     return {
-      'productIDs': ((dynamic v) =>v.map((v) => v).cast<String>().toList())(productIDs),
+      'productIDs': ((dynamic v) => v.map((v) => v).cast<String>().toList())(productIDs),
     };
   }
 
@@ -61,7 +61,7 @@ class RecommendationClient {
 
 
   Future<ListResponse> list(ListRequest request) async {
-    final response = await ftlClient.get('/recommendation', request: request.toMap());
+    final response = await ftlClient.get('/recommendation', requestJson: request.toJson());
     if (response.statusCode == 200) {
       return ListResponse.fromJson(response.body);
     } else {
diff --git a/frontend/mobile/lib/api/shipping.dart b/frontend/mobile/lib/api/shipping.dart
index d4d958e8..fd2a9381 100644
--- a/frontend/mobile/lib/api/shipping.dart
+++ b/frontend/mobile/lib/api/shipping.dart
@@ -3,6 +3,8 @@ library shipping;
 
 import 'dart:convert';
 import 'ftl_client.dart';
+import 'cart.dart' as cart;
+import 'currency.dart' as currency;
 
 
 class Address {
@@ -12,15 +14,15 @@ class Address {
   String country;
   int zipCode;
 
-  Address({ required this.streetAddress, required this.city, required this.state, required this.country, required this.zipCode,  });
+  Address({  required this.streetAddress,  required this.city,  required this.state,  required this.country,  required this.zipCode,  });
 
   Map<String, dynamic> toMap() {
     return {
-      'streetAddress': ((dynamic v) =>v)(streetAddress),
-      'city': ((dynamic v) =>v)(city),
-      'state': ((dynamic v) =>v)(state),
-      'country': ((dynamic v) =>v)(country),
-      'zipCode': ((dynamic v) =>v)(zipCode),
+      'streetAddress': ((dynamic v) => v)(streetAddress),
+      'city': ((dynamic v) => v)(city),
+      'state': ((dynamic v) => v)(state),
+      'country': ((dynamic v) => v)(country),
+      'zipCode': ((dynamic v) => v)(zipCode),
     };
   }
 
@@ -39,48 +41,23 @@ class Address {
   factory Address.fromJson(String source) => Address.fromMap(json.decode(source));
 }
 
-class Item {
-  String productID;
-  int quantity;
-
-  Item({ required this.productID, required this.quantity,  });
-
-  Map<String, dynamic> toMap() {
-    return {
-      'productID': ((dynamic v) =>v)(productID),
-      'quantity': ((dynamic v) =>v)(quantity),
-    };
-  }
-
-  factory Item.fromMap(Map<String, dynamic> map) {
-    return Item(
-      productID: ((dynamic v) => v)(map['productID']),
-      quantity: ((dynamic v) => v)(map['quantity']),
-    );
-  }
-
-  String toJson() => json.encode(toMap());
-
-  factory Item.fromJson(String source) => Item.fromMap(json.decode(source));
-}
-
 class ShippingRequest {
   Address address;
-  List<Item> items;
+  List<cart.Item> items;
 
-  ShippingRequest({ required this.address, required this.items,  });
+  ShippingRequest({  required this.address,  required this.items,  });
 
   Map<String, dynamic> toMap() {
     return {
-      'address': ((dynamic v) =>v.toMap())(address),
-      'items': ((dynamic v) =>v.map((v) => Item.fromMap(v)).cast<Item>().toList())(items),
+      'address': ((dynamic v) => v.toMap())(address),
+      'items': ((dynamic v) => v.map((v) => cart.Item.fromMap(v)).cast<cart.Item>().toList())(items),
     };
   }
 
   factory ShippingRequest.fromMap(Map<String, dynamic> map) {
     return ShippingRequest(
       address: ((dynamic v) => Address.fromMap(v))(map['address']),
-      items: ((dynamic v) => v.map((v) => Item.fromMap(v)).cast<Item>().toList())(map['items']),
+      items: ((dynamic v) => v.map((v) => cart.Item.fromMap(v)).cast<cart.Item>().toList())(map['items']),
     );
   }
 
@@ -89,42 +66,14 @@ class ShippingRequest {
   factory ShippingRequest.fromJson(String source) => ShippingRequest.fromMap(json.decode(source));
 }
 
-class Money {
-  String currencyCode;
-  int units;
-  int nanos;
-
-  Money({ required this.currencyCode, required this.units, required this.nanos,  });
-
-  Map<String, dynamic> toMap() {
-    return {
-      'currencyCode': ((dynamic v) =>v)(currencyCode),
-      'units': ((dynamic v) =>v)(units),
-      'nanos': ((dynamic v) =>v)(nanos),
-    };
-  }
-
-  factory Money.fromMap(Map<String, dynamic> map) {
-    return Money(
-      currencyCode: ((dynamic v) => v)(map['currencyCode']),
-      units: ((dynamic v) => v)(map['units']),
-      nanos: ((dynamic v) => v)(map['nanos']),
-    );
-  }
-
-  String toJson() => json.encode(toMap());
-
-  factory Money.fromJson(String source) => Money.fromMap(json.decode(source));
-}
-
 class ShipOrderResponse {
   String id;
 
-  ShipOrderResponse({ required this.id,  });
+  ShipOrderResponse({  required this.id,  });
 
   Map<String, dynamic> toMap() {
     return {
-      'id': ((dynamic v) =>v)(id),
+      'id': ((dynamic v) => v)(id),
     };
   }
 
@@ -146,10 +95,10 @@ class ShippingClient {
   ShippingClient({required this.ftlClient});
 
 
-  Future<Money> getQuote(ShippingRequest request) async {
+  Future<currency.Money> getQuote(ShippingRequest request) async {
     final response = await ftlClient.post('/shipping/quote', request: request.toMap());
     if (response.statusCode == 200) {
-      return Money.fromJson(response.body);
+      return currency.Money.fromJson(response.body);
     } else {
       throw Exception('Failed to get getQuote response');
     }
diff --git a/frontend/mobile/lib/utils/money_utils.dart b/frontend/mobile/lib/utils/money_utils.dart
index 850db079..db8f8cf5 100644
--- a/frontend/mobile/lib/utils/money_utils.dart
+++ b/frontend/mobile/lib/utils/money_utils.dart
@@ -1,4 +1,4 @@
-import 'package:online_boutique/api/productcatalog.dart';
+import 'package:online_boutique/api/currency.dart';
 
 String fromMoney(Money money) {
   return "${money.currencyCode} ${money.units}.${money.nanos.toString().padLeft(9, '0').substring(0, 2)}";
diff --git a/frontend/mobile/templates/ftl_client.dart b/frontend/mobile/templates/ftl_client.dart
index f93b686b..3ce3a52f 100644
--- a/frontend/mobile/templates/ftl_client.dart
+++ b/frontend/mobile/templates/ftl_client.dart
@@ -21,14 +21,14 @@ class FTLHttpClient {
 
   Future<http.Response> get(
     String path, {
-    Map<String, dynamic>? request,
+    String? requestJson,
     Map<String, String>? headers,
   }) {
     Uri uri;
-    if (request == null || request.isEmpty) {
+    if (requestJson == null || requestJson.isEmpty) {
       uri = Uri.http("localhost:8892", '/ingress$path');
     } else {
-      uri = Uri.http("localhost:8892", '/ingress$path', request);
+      uri = Uri.http("localhost:8892", '/ingress$path', {'@json': requestJson});
     }
     return httpClient.get(uri, headers: headers);
   }
diff --git a/frontend/mobile/templates/template.js b/frontend/mobile/templates/template.js
new file mode 100644
index 00000000..f8bd7e84
--- /dev/null
+++ b/frontend/mobile/templates/template.js
@@ -0,0 +1,81 @@
+// Return the corresponding Dart type for an FTL type.
+function dartType(t) {
+    const type = typeName(t);
+    switch (type) {
+      case "String":
+        return "String";
+  
+      case "Int":
+        return "int";
+  
+      case "Bool":
+        return "bool";
+  
+      case "Float":
+        return "double";
+  
+      case "Time":
+        return "DateTime";
+  
+      case "Map":
+        return `Map<${dartType(t.key)}, ${dartType(t.value)}>`;
+  
+      case "Array":
+        return `List<${dartType(t.element)}>`;
+  
+      case "VerbRef":
+      case "DataRef":
+        if (context.name === t.module) {
+          return t.name;
+        }
+        return `${t.module}.${t.name}`;
+  
+      case "Optional":
+        return dartType(t.type) + "?";
+  
+      default:
+        throw new Error(`Unspported FTL type: ${typeName(t)}`);
+    }
+  }
+  
+  function deserialize(t) {
+    switch (typeName(t)) {
+      case "Array":
+        return `v.map((v) => ${deserialize(t.element)}).cast<${dartType(t.element)}>().toList()`;
+  
+      case "Map":
+        return `v.map((k, v) => MapEntry(k, ${deserialize(t.value)})).cast<${dartType(t.key)}, ${dartType(t.value)}>()`;
+  
+      case "DataRef":
+        return `${dartType(t)}.fromMap(v)`;
+  
+      default:
+        return "v";
+    }
+  }
+  
+  function serialize(t) {
+    switch (typeName(t)) {
+      case "Array":
+        return `v.map((v) => ${deserialize(t.element)}).cast<${dartType(t.element)}>().toList()`;
+  
+      case "Map":
+        return `v.map((k, v) => MapEntry(k, ${deserialize(t.value)})).cast<${dartType(t.key)}, ${dartType(t.value)}>()`;
+  
+      case "DataRef":
+        return "v.toMap()";
+  
+      default:
+        return "v";
+    }
+  }
+  
+  function url(verb) {
+    let path = verb.metadata[0].path;
+    const method = verb.metadata[0].method;
+    console.log(path);
+    
+    return path.replace(/{(.*?)}/g, (match, fieldName) => {
+      return '$' + `{request.${fieldName}}`;
+    });
+  }
diff --git a/frontend/mobile/templates/{{ .Name | lower }}.dart b/frontend/mobile/templates/{{ .Name | lower }}.dart
index 5caf6d24..586499e6 100644
--- a/frontend/mobile/templates/{{ .Name | lower }}.dart	
+++ b/frontend/mobile/templates/{{ .Name | lower }}.dart	
@@ -3,60 +3,22 @@ library {{ .Name | lower }};
 
 import 'dart:convert';
 import 'ftl_client.dart';
-{{- range .Imports}}
+{{- range .Imports }}
 import '{{. | lower }}.dart' as {{. | lower}};
 {{- end}}
 
-{{- define "darttype" -}}
-{{- $type := (. | typename ) -}}
-{{- if eq $type "Array" }}List<{{ template "darttype" .Element }}>
-{{- else if eq $type "Map" }}Map<{{ template "darttype" .Key }}, {{ template "darttype" .Value }}>
-{{- else if eq $type "DataRef" }}{{ . }}
-{{- else if eq $type "Int" }}int
-{{- else if eq $type "Bool" }}bool
-{{- else if eq $type "Float" }}double
-{{- else if eq $type "Time" }}DateTime
-{{- else -}}{{ . | typename }}{{- end -}}
-{{- end }}
-
-{{- define "deserialize" -}}
-{{- $type := (. | typename ) -}}
-{{- if eq $type "Array" -}}
-v.map((v) => {{ template "deserialize" .Element }}).cast<{{ template "darttype" .Element }}>().toList()
-{{- else if eq $type "Map" -}}
-v.map((k, v) => MapEntry(k, {{ template "deserialize" .Value }})).cast<{{ template "darttype" .Key }}, {{ template "darttype" .Value }}>()
-{{- else if eq $type "DataRef" -}}
-{{ . }}.fromMap(v)
-{{- else -}}
-v
-{{- end }}
-{{- end }}
-
-{{- define "serialize" -}}
-{{- $type := (. | typename ) -}}
-{{- if eq $type "Array" -}}
-v.map((v) => {{ template "deserialize" .Element }}).cast<{{ template "darttype" .Element }}>().toList()
-{{- else if eq $type "Map" -}}
-v.map((k, v) => MapEntry(k, {{ template "deserialize" .Value }})).cast<{{ template "darttype" .Key }}, {{ template "darttype" .Value }}>()
-{{- else if eq $type "DataRef" -}}
-v.toMap()
-{{- else -}}
-v
-{{- end }}
-{{- end }}
-
 {{ range .Data }}
 class {{ .Name | camel }} {
 {{- range .Fields }}
-  {{ template "darttype" .Type }} {{ .Name }};
+  {{ .Type | dartType }} {{ .Name }};
 {{- end }}
 
-  {{ .Name | camel }}({{ if .Fields }}{ {{ range .Fields }}required this.{{ .Name }}, {{ end}} }{{ end }});
+  {{ .Name | camel }}({{ if .Fields }}{ {{ range .Fields }}{{ if not (eq (.Type | typeName) "Optional")}} required{{end}} this.{{ .Name }}, {{ end}} }{{ end }});
 
   Map<String, dynamic> toMap() {
     return {
 {{- range .Fields}}
-      '{{ .Name }}': ((dynamic v) =>{{ template "serialize" .Type }})({{ .Name }}),
+      '{{ .Name }}': ((dynamic v) => {{ .Type | serialize }})({{ .Name }}),
 {{- end }}
     };
   }
@@ -64,7 +26,7 @@ class {{ .Name | camel }} {
   factory {{ .Name | camel }}.fromMap(Map<String, dynamic> map) {
     return {{ .Name | camel }}(
 {{- range .Fields }}
-      {{ .Name }}: ((dynamic v) => {{ template "deserialize" .Type }})(map['{{ .Name }}']),
+      {{ .Name }}: ((dynamic v) => {{ .Type | deserialize }})(map['{{ .Name }}']),
 {{- end }}
     );
   }
@@ -82,11 +44,15 @@ class {{ .Name | camel }}Client {
 {{ range .Verbs }}
 {{- $verb := . -}}
 {{- range .Metadata }}
-{{ if eq "MetadataIngress" (. | typename) }}
-  Future<{{ $verb.Response }}> {{ $verb.Name }}({{ $verb.Request }} request) async {
-    final response = await ftlClient.{{ .Method | lower }}('{{ .Path }}', request: request.toMap());
+{{ if eq "MetadataIngress" (. | typeName) }}
+  Future<{{ $verb.Response | dartType }}> {{ $verb.Name }}({{ $verb.Request | dartType }} request) async {
+    {{ if eq .Method "GET" -}}
+    final response = await ftlClient.{{ .Method | lower }}('{{ $verb | url }}', requestJson: request.toJson());
+    {{ else -}}
+    final response = await ftlClient.{{ .Method | lower }}('{{ $verb | url }}', request: request.toMap());
+    {{ end -}}
     if (response.statusCode == 200) {
-      return {{ $verb.Response }}.fromJson(response.body);
+      return {{ $verb.Response | dartType }}.fromJson(response.body);
     } else {
       throw Exception('Failed to get {{ $verb.Name }} response');
     }
diff --git a/frontend/web/src/api/ad.ts b/frontend/web/src/api/ad.ts
index e0e3652f..0826a036 100644
--- a/frontend/web/src/api/ad.ts
+++ b/frontend/web/src/api/ad.ts
@@ -6,7 +6,9 @@
 //  /_/   /_/ /____/            
 //
 // @ts-ignore ignore unused error in generated code
-import { toQueryString } from "./utils";
+//
+
+
 export interface AdRequest {
   contextKeys: string[];
 }
@@ -17,6 +19,7 @@ export interface Ad {
 }
 
 export interface AdResponse {
+  name: string;
   ads: Ad[];
 }
 
@@ -28,8 +31,10 @@ export class AdClient {
     this.baseUrl = baseUrl;
   }
 
+
   public async get(request: AdRequest): Promise<AdResponse> {
-    const response = await fetch(`${this.baseUrl}/ad?${toQueryString(request)}`, {
+    const path = `/ad?@json=${encodeURIComponent(JSON.stringify(request))}`;
+    const response = await fetch(`${this.baseUrl}${path}`, {
       method: 'GET',
       headers: {
         'Content-Type': 'application/json',
diff --git a/frontend/web/src/api/cart.ts b/frontend/web/src/api/cart.ts
index 8ea9727a..059f1935 100644
--- a/frontend/web/src/api/cart.ts
+++ b/frontend/web/src/api/cart.ts
@@ -6,7 +6,9 @@
 //  /_/   /_/ /____/            
 //
 // @ts-ignore ignore unused error in generated code
-import { toQueryString } from "./utils";
+//
+
+
 export interface Item {
   productID: string;
   quantity: number;
@@ -44,8 +46,10 @@ export class CartClient {
     this.baseUrl = baseUrl;
   }
 
+
   public async addItem(request: AddItemRequest): Promise<AddItemResponse> {
-    const response = await fetch(`${this.baseUrl}/cart/add`, {
+    const path = `/cart/add`;
+    const response = await fetch(`${this.baseUrl}${path}`, {
       method: 'POST',
       headers: {
         'Content-Type': 'application/json',
@@ -58,8 +62,10 @@ export class CartClient {
     return response.json();
   }
 
+
   public async getCart(request: GetCartRequest): Promise<Cart> {
-    const response = await fetch(`${this.baseUrl}/cart?${toQueryString(request)}`, {
+    const path = `/cart?@json=${encodeURIComponent(JSON.stringify(request))}`;
+    const response = await fetch(`${this.baseUrl}${path}`, {
       method: 'GET',
       headers: {
         'Content-Type': 'application/json',
@@ -72,8 +78,10 @@ export class CartClient {
     return response.json();
   }
 
+
   public async emptyCart(request: EmptyCartRequest): Promise<EmptyCartResponse> {
-    const response = await fetch(`${this.baseUrl}/cart/empty`, {
+    const path = `/cart/empty`;
+    const response = await fetch(`${this.baseUrl}${path}`, {
       method: 'POST',
       headers: {
         'Content-Type': 'application/json',
diff --git a/frontend/web/src/api/checkout.ts b/frontend/web/src/api/checkout.ts
index 74e98f13..1b6b36cb 100644
--- a/frontend/web/src/api/checkout.ts
+++ b/frontend/web/src/api/checkout.ts
@@ -6,51 +6,32 @@
 //  /_/   /_/ /____/            
 //
 // @ts-ignore ignore unused error in generated code
-import { toQueryString } from "./utils";
-export interface Address {
-  streetAddress: string;
-  city: string;
-  state: string;
-  country: string;
-  zipCode: number;
-}
+//
+import * as shipping from "./shipping"
+import * as payment from "./payment"
+import * as cart from "./cart"
+import * as currency from "./currency"
+import * as productcatalog from "./productcatalog"
 
-export interface CreditCardInfo {
-  number: string;
-  cVV: number;
-  expirationYear: number;
-  expirationMonth: number;
-}
 
 export interface PlaceOrderRequest {
   userID: string;
   userCurrency: string;
-  address: Address;
+  address: shipping.Address;
   email: string;
-  creditCard: CreditCardInfo;
-}
-
-export interface Money {
-  currencyCode: string;
-  units: number;
-  nanos: number;
-}
-
-export interface Item {
-  productID: string;
-  quantity: number;
+  creditCard: payment.CreditCardInfo;
 }
 
 export interface OrderItem {
-  item: Item;
-  cost: Money;
+  item: cart.Item;
+  cost: currency.Money;
 }
 
 export interface Order {
   id: string;
   shippingTrackingID: string;
-  shippingCost: Money;
-  shippingAddress: Address;
+  shippingCost: currency.Money;
+  shippingAddress: shipping.Address;
   items: OrderItem[];
 }
 
@@ -62,8 +43,10 @@ export class CheckoutClient {
     this.baseUrl = baseUrl;
   }
 
+
   public async placeOrder(request: PlaceOrderRequest): Promise<Order> {
-    const response = await fetch(`${this.baseUrl}/checkout`, {
+    const path = `/checkout/${request.userID}`;
+    const response = await fetch(`${this.baseUrl}${path}`, {
       method: 'POST',
       headers: {
         'Content-Type': 'application/json',
diff --git a/frontend/web/src/api/currency.ts b/frontend/web/src/api/currency.ts
index edefbcdb..a09b860a 100644
--- a/frontend/web/src/api/currency.ts
+++ b/frontend/web/src/api/currency.ts
@@ -6,7 +6,9 @@
 //  /_/   /_/ /____/            
 //
 // @ts-ignore ignore unused error in generated code
-import { toQueryString } from "./utils";
+//
+
+
 export interface GetSupportedCurrenciesRequest {
 }
 
@@ -33,8 +35,10 @@ export class CurrencyClient {
     this.baseUrl = baseUrl;
   }
 
+
   public async getSupportedCurrencies(request: GetSupportedCurrenciesRequest): Promise<GetSupportedCurrenciesResponse> {
-    const response = await fetch(`${this.baseUrl}/currency/supported?${toQueryString(request)}`, {
+    const path = `/currency/supported?@json=${encodeURIComponent(JSON.stringify(request))}`;
+    const response = await fetch(`${this.baseUrl}${path}`, {
       method: 'GET',
       headers: {
         'Content-Type': 'application/json',
@@ -47,8 +51,10 @@ export class CurrencyClient {
     return response.json();
   }
 
+
   public async convert(request: ConvertRequest): Promise<Money> {
-    const response = await fetch(`${this.baseUrl}/currency/convert`, {
+    const path = `/currency/convert`;
+    const response = await fetch(`${this.baseUrl}${path}`, {
       method: 'POST',
       headers: {
         'Content-Type': 'application/json',
diff --git a/frontend/web/src/api/payment.ts b/frontend/web/src/api/payment.ts
index 11c762be..6a2c6960 100644
--- a/frontend/web/src/api/payment.ts
+++ b/frontend/web/src/api/payment.ts
@@ -6,12 +6,9 @@
 //  /_/   /_/ /____/            
 //
 // @ts-ignore ignore unused error in generated code
-import { toQueryString } from "./utils";
-export interface Money {
-  currencyCode: string;
-  units: number;
-  nanos: number;
-}
+//
+import * as currency from "./currency"
+
 
 export interface CreditCardInfo {
   number: string;
@@ -21,7 +18,7 @@ export interface CreditCardInfo {
 }
 
 export interface ChargeRequest {
-  amount: Money;
+  amount: currency.Money;
   creditCard: CreditCardInfo;
 }
 
@@ -37,8 +34,10 @@ export class PaymentClient {
     this.baseUrl = baseUrl;
   }
 
+
   public async charge(request: ChargeRequest): Promise<ChargeResponse> {
-    const response = await fetch(`${this.baseUrl}/payment/charge`, {
+    const path = `/payment/charge`;
+    const response = await fetch(`${this.baseUrl}${path}`, {
       method: 'POST',
       headers: {
         'Content-Type': 'application/json',
diff --git a/frontend/web/src/api/productcatalog.ts b/frontend/web/src/api/productcatalog.ts
index 4940e040..1b27f454 100644
--- a/frontend/web/src/api/productcatalog.ts
+++ b/frontend/web/src/api/productcatalog.ts
@@ -6,14 +6,11 @@
 //  /_/   /_/ /____/            
 //
 // @ts-ignore ignore unused error in generated code
-import { toQueryString } from "./utils";
-export interface ListRequest {
-}
+//
+import * as currency from "./currency"
+
 
-export interface Money {
-  currencyCode: string;
-  units: number;
-  nanos: number;
+export interface ListRequest {
 }
 
 export interface Product {
@@ -21,7 +18,7 @@ export interface Product {
   name: string;
   description: string;
   picture: string;
-  priceUSD: Money;
+  priceUSD: currency.Money;
   categories: string[];
 }
 
@@ -49,8 +46,10 @@ export class ProductcatalogClient {
     this.baseUrl = baseUrl;
   }
 
+
   public async list(request: ListRequest): Promise<ListResponse> {
-    const response = await fetch(`${this.baseUrl}/productcatalog?${toQueryString(request)}`, {
+    const path = `/productcatalog?@json=${encodeURIComponent(JSON.stringify(request))}`;
+    const response = await fetch(`${this.baseUrl}${path}`, {
       method: 'GET',
       headers: {
         'Content-Type': 'application/json',
@@ -63,8 +62,10 @@ export class ProductcatalogClient {
     return response.json();
   }
 
+
   public async get(request: GetRequest): Promise<Product> {
-    const response = await fetch(`${this.baseUrl}/productcatalog/id?${toQueryString(request)}`, {
+    const path = `/productcatalog/${request.id}?@json=${encodeURIComponent(JSON.stringify(request))}`;
+    const response = await fetch(`${this.baseUrl}${path}`, {
       method: 'GET',
       headers: {
         'Content-Type': 'application/json',
diff --git a/frontend/web/src/api/recommendation.ts b/frontend/web/src/api/recommendation.ts
index f36c8a7c..7010afbe 100644
--- a/frontend/web/src/api/recommendation.ts
+++ b/frontend/web/src/api/recommendation.ts
@@ -6,7 +6,10 @@
 //  /_/   /_/ /____/            
 //
 // @ts-ignore ignore unused error in generated code
-import { toQueryString } from "./utils";
+//
+import * as productcatalog from "./productcatalog"
+
+
 export interface ListRequest {
   userID: string;
   userProductIDs: string[];
@@ -24,8 +27,10 @@ export class RecommendationClient {
     this.baseUrl = baseUrl;
   }
 
+
   public async list(request: ListRequest): Promise<ListResponse> {
-    const response = await fetch(`${this.baseUrl}/recommendation?${toQueryString(request)}`, {
+    const path = `/recommendation?@json=${encodeURIComponent(JSON.stringify(request))}`;
+    const response = await fetch(`${this.baseUrl}${path}`, {
       method: 'GET',
       headers: {
         'Content-Type': 'application/json',
diff --git a/frontend/web/src/api/shipping.ts b/frontend/web/src/api/shipping.ts
index fde1a288..01ee55a2 100644
--- a/frontend/web/src/api/shipping.ts
+++ b/frontend/web/src/api/shipping.ts
@@ -6,7 +6,11 @@
 //  /_/   /_/ /____/            
 //
 // @ts-ignore ignore unused error in generated code
-import { toQueryString } from "./utils";
+//
+import * as currency from "./currency"
+import * as cart from "./cart"
+
+
 export interface Address {
   streetAddress: string;
   city: string;
@@ -15,20 +19,9 @@ export interface Address {
   zipCode: number;
 }
 
-export interface Item {
-  productID: string;
-  quantity: number;
-}
-
 export interface ShippingRequest {
   address: Address;
-  items: Item[];
-}
-
-export interface Money {
-  currencyCode: string;
-  units: number;
-  nanos: number;
+  items: cart.Item[];
 }
 
 export interface ShipOrderResponse {
@@ -43,8 +36,10 @@ export class ShippingClient {
     this.baseUrl = baseUrl;
   }
 
-  public async getQuote(request: ShippingRequest): Promise<Money> {
-    const response = await fetch(`${this.baseUrl}/shipping/quote`, {
+
+  public async getQuote(request: ShippingRequest): Promise<currency.Money> {
+    const path = `/shipping/quote`;
+    const response = await fetch(`${this.baseUrl}${path}`, {
       method: 'POST',
       headers: {
         'Content-Type': 'application/json',
@@ -57,8 +52,10 @@ export class ShippingClient {
     return response.json();
   }
 
+
   public async shipOrder(request: ShippingRequest): Promise<ShipOrderResponse> {
-    const response = await fetch(`${this.baseUrl}/shipping/ship`, {
+    const path = `/shipping/ship`;
+    const response = await fetch(`${this.baseUrl}${path}`, {
       method: 'POST',
       headers: {
         'Content-Type': 'application/json',
diff --git a/frontend/web/templates/template.js b/frontend/web/templates/template.js
new file mode 100644
index 00000000..92ac7302
--- /dev/null
+++ b/frontend/web/templates/template.js
@@ -0,0 +1,82 @@
+// Return the corresponding Typescript type for an FTL type.
+function tsType(t) {
+    const type = typeName(t);
+    switch (type) {
+      case "String":
+        return "string";
+  
+      case "Int":
+        return "number";
+  
+      case "Bool":
+        return "bool";
+  
+      case "Float":
+        return "double";
+  
+      case "Time":
+        return "DateTime";
+  
+      case "Map":
+        return `Map<${tsType(t.key)}, ${tsType(t.value)}>`;
+  
+      case "Array":
+        return `${tsType(t.element)}[]`;
+  
+      case "VerbRef":
+      case "DataRef":
+        if (context.name === t.module) {
+          return t.name;
+        }
+        return `${t.module}.${t.name}`;
+  
+      case "Optional":
+        return tsType(t.type) + "?";
+  
+      default:
+        throw new Error(`Unspported FTL type: ${typeName(t)}`);
+    }
+  }
+  
+  function deserialize(t) {
+    switch (typeName(t)) {
+      case "Array":
+        return `v.map((v) => ${deserialize(t.element)}).cast<${tsType(t.element)}>().toList()`;
+  
+      case "Map":
+        return `v.map((k, v) => MapEntry(k, ${deserialize(t.value)})).cast<${tsType(t.key)}, ${tsType(t.value)}>()`;
+  
+      case "DataRef":
+        return `${tsType(t)}.fromMap(v)`;
+  
+      default:
+        return "v";
+    }
+  }
+  
+  function serialize(t) {
+    switch (typeName(t)) {
+      case "Array":
+        return `v.map((v) => ${deserialize(t.element)}).cast<${tsType(t.element)}>().toList()`;
+  
+      case "Map":
+        return `v.map((k, v) => MapEntry(k, ${deserialize(t.value)})).cast<${tsType(t.key)}, ${tsType(t.value)}>()`;
+  
+      case "DataRef":
+        return "v.toMap()";
+  
+      default:
+        return "v";
+    }
+  }
+  
+  function url(verb) {
+    let path = verb.metadata[0].path;
+    const method = verb.metadata[0].method;
+    
+    path = path.replace(/{(.*?)}/g, (match, fieldName) => {
+      return '$' + `{request.${fieldName}}`;
+    });
+
+    return method !== 'GET' ? path : path + '?@json=${encodeURIComponent(JSON.stringify(request))}';
+  }
diff --git a/frontend/web/templates/{{ .Name | lower }}.ts b/frontend/web/templates/{{ .Name | lower }}.ts
index 2be44e0f..71c70a24 100644
--- a/frontend/web/templates/{{ .Name | lower }}.ts	
+++ b/frontend/web/templates/{{ .Name | lower }}.ts	
@@ -6,21 +6,16 @@
 //  /_/   /_/ /____/            
 //
 // @ts-ignore ignore unused error in generated code
-import { toQueryString } from "./utils";
-{{- define "tstype" -}}
-{{- $type := (. | typename ) -}}
-{{- if eq $type "Array" }}{{ template "tstype" .Element }}[]
-{{- else if eq $type "Map" }}Map<{{ template "tstype" .Key }}, {{ template "tstype" .Value }}>
-{{- else if eq $type "DataRef" }}{{ . }}
-{{- else if eq $type "Int" }}number
-{{- else if eq $type "String" }}string
-{{- else -}}{{ . | typename }}{{- end -}}
-{{- end -}}
+// 
+
+{{- range .Imports }}
+import * as {{. | lower }} from "./{{. | lower}}"
+{{- end}}
 
 {{ range .Data }}
 export interface {{ .Name | camel }} {
 {{- range .Fields }}
-  {{ .Name }}: {{ template "tstype" .Type }};
+  {{ .Name }}: {{ .Type | tsType }};
 {{- end }}
 }
 {{ end}}
@@ -31,22 +26,22 @@ export class {{ .Name | camel }}Client {
   constructor(baseUrl: string) {
     this.baseUrl = baseUrl;
   }
-
 {{- range .Verbs }}
 {{- $verb := . -}}
 {{- range .Metadata }}
-{{ if eq "MetadataIngress" (. | typename) }}
-  public async {{ $verb.Name | lowerCamel }}(request: {{ $verb.Request }}): Promise<{{ $verb.Response }}> {
+{{ if eq "MetadataIngress" (. | typeName) }}
+
+  public async {{ $verb.Name | lowerCamel }}(request: {{ $verb.Request | tsType }}): Promise<{{ $verb.Response | tsType }}> {
+    const path = `{{ $verb | url }}`;
     {{ if eq .Method "GET" -}}
-    
-    const response = await fetch(`${this.baseUrl}{{ .Path }}?${toQueryString(request)}`, {
+    const response = await fetch(`${this.baseUrl}${path}`, {
       method: 'GET',
       headers: {
         'Content-Type': 'application/json',
       },
     });
     {{ else if eq .Method "POST" -}}
-    const response = await fetch(`${this.baseUrl}{{ .Path }}`, {
+    const response = await fetch(`${this.baseUrl}${path}`, {
       method: 'POST',
       headers: {
         'Content-Type': 'application/json',