prisma/catalog.prisma

@@ -35,6 +35,8 @@ model ProductVariant {
   attributes Json @default("{}")
   active Boolean @default(true)
   stockItems StockItem[]
+  cartLines CartLine[]
+  orderLines OrderLine[]
   product Product @relation(fields: [productId, organizationId], references: [id, organizationId], onDelete: Restrict)
   @@unique([organizationId, sku])
   @@unique([id, organizationId])
@@ -63,5 +65,3 @@ model ProductGroup {
   @@index([groupId, organizationId])
   @@map("product_groups")
 }
-
-

prisma/checkout.prisma

@@ -0,0 +1,93 @@
+enum OrderStatus {
+  PENDING_PAYMENT
+  CANCELLED
+}
+enum CouponKind {
+  FIXED
+  PERCENT
+}
+model Cart {
+  id String @id @default(uuid()) @db.Uuid
+  organizationId String @map("organization_id") @db.Uuid
+  userId String @map("user_id") @db.Uuid
+  version Int @default(0)
+  user User @relation(fields: [userId, organizationId], references: [id, organizationId], onDelete: Restrict)
+  lines CartLine[]
+  @@unique([userId, organizationId])
+  @@unique([id, organizationId])
+  @@map("carts")
+}
+model CartLine {
+  id String @id @default(uuid()) @db.Uuid
+  cartId String @map("cart_id") @db.Uuid
+  organizationId String @map("organization_id") @db.Uuid
+  variantId String @map("variant_id") @db.Uuid
+  quantity Int
+  cart Cart @relation(fields: [cartId, organizationId], references: [id, organizationId], onDelete: Cascade)
+  variant ProductVariant @relation(fields: [variantId, organizationId], references: [id, organizationId], onDelete: Restrict)
+  @@unique([cartId, variantId])
+  @@map("cart_lines")
+}
+model Coupon {
+  id String @id @default(uuid()) @db.Uuid
+  organizationId String @map("organization_id") @db.Uuid
+  code String @db.VarChar(40)
+  kind CouponKind
+  currency String @db.Char(3)
+  amount Decimal? @db.Decimal(12,2)
+  percentBps Int? @map("percent_bps")
+  minimumSubtotal Decimal @default(0) @map("minimum_subtotal") @db.Decimal(12,2)
+  maxUses Int @map("max_uses")
+  perUserLimit Int @map("per_user_limit")
+  startsAt DateTime @map("starts_at") @db.Timestamptz(3)
+  endsAt DateTime @map("ends_at") @db.Timestamptz(3)
+  active Boolean @default(true)
+  organization Organization @relation(fields: [organizationId], references: [id], onDelete: Restrict)
+  orders Order[]
+  @@unique([organizationId, code])
+  @@unique([id, organizationId])
+  @@map("coupons")
+}
+model Order {
+  id String @id @default(uuid()) @db.Uuid
+  organizationId String @map("organization_id") @db.Uuid
+  userId String @map("user_id") @db.Uuid
+  status OrderStatus @default(PENDING_PAYMENT)
+  currency String @db.Char(3)
+  subtotal Decimal @db.Decimal(16,2)
+  discount Decimal @db.Decimal(16,2)
+  merchandiseTotal Decimal @map("merchandise_total") @db.Decimal(16,2)
+  addressSnapshot Json @map("address_snapshot")
+  couponSnapshot Json? @map("coupon_snapshot")
+  couponId String? @map("coupon_id") @db.Uuid
+  idempotencyKey String @map("idempotency_key") @db.Uuid
+  requestHash String @map("request_hash") @db.Char(64)
+  expiresAt DateTime @map("expires_at") @db.Timestamptz(3)
+  createdAt DateTime @default(now()) @map("created_at") @db.Timestamptz(3)
+  user User @relation(fields: [userId, organizationId], references: [id, organizationId], onDelete: Restrict)
+  coupon Coupon? @relation(fields: [couponId, organizationId], references: [id, organizationId], onDelete: Restrict)
+  lines OrderLine[]
+  reservations StockReservation[]
+  @@unique([userId, organizationId, idempotencyKey])
+  @@unique([id, organizationId])
+  @@index([organizationId, userId, createdAt, id])
+  @@unique([id, userId, organizationId])
+  @@index([couponId, status, expiresAt])
+  @@map("orders")
+}
+model OrderLine {
+  id String @id @default(uuid()) @db.Uuid
+  orderId String @map("order_id") @db.Uuid
+  organizationId String @map("organization_id") @db.Uuid
+  variantId String @map("variant_id") @db.Uuid
+  sku String @db.VarChar(64)
+  productName String @map("product_name") @db.VarChar(160)
+  variantName String @map("variant_name") @db.VarChar(160)
+  quantity Int
+  unitPrice Decimal @map("unit_price") @db.Decimal(12,2)
+  lineTotal Decimal @map("line_total") @db.Decimal(16,2)
+  order Order @relation(fields: [orderId, organizationId], references: [id, organizationId], onDelete: Restrict)
+  variant ProductVariant @relation(fields: [variantId, organizationId], references: [id, organizationId], onDelete: Restrict)
+  @@unique([orderId, variantId])
+  @@map("order_lines")
+}

prisma/inventory.prisma

@@ -50,6 +50,8 @@ model StockReservation {
   organizationId String @map("organization_id") @db.Uuid
   userId String @map("user_id") @db.Uuid
   user User @relation(fields: [userId, organizationId], references: [id, organizationId], onDelete: Restrict)
+  orderId String? @map("order_id") @db.Uuid
+  order Order? @relation(fields: [orderId, userId, organizationId], references: [id, userId, organizationId], onDelete: Restrict)
   quantity Int
   status ReservationStatus @default(ACTIVE)
   idempotencyKey String @map("idempotency_key") @db.Uuid
@@ -62,5 +64,3 @@ model StockReservation {
   @@index([userId, organizationId])
   @@map("stock_reservations")
 }
-
-

prisma/migration-checksums.json

@@ -5,5 +5,9 @@
   "20260909141447_catalog_addresses": "c89cc9448494d74f8e5ee0005e81b6265bb01d7f000a81c4af27dc3c9855ba84",
   "20260909141549_inventory": "ab5b0afde7332dd8de3190781dde95bd941bba91ab525308a7436d108cef7e36",
   "20260909141622_commerce_integrity": "30545784aa33f35783c0170b80de2bded32be8781e25e027c4e5e2e5da8348ac",
-  "20260909153911_inventory_actor_scope": "7d6d2df3a8229032022f5a2ce43ed37c508c4a71743fd2bc6c24786634611d1e"
+  "20260909153911_inventory_actor_scope": "7d6d2df3a8229032022f5a2ce43ed37c508c4a71743fd2bc6c24786634611d1e",
+  "20260910182626_checkout_orders": "aa924db3868c96475c8255800788de42d8e7447cf0a2c84b789b116e533582cb",
+  "20260910182800_checkout_integrity": "e88b972ab16a4cd95f6fb4f097ce41ddfc7917899dc3803a1e7757c3e56c19b2",
+  "20260910183016_checkout_snapshot_guards": "f1c7a95b5a620e06a518a96d457fb493241bd2d5e7deb6b5788ad85c8f3b59f7",
+  "20260910184357_order_reconciliation": "c32e7a917618e02ed1658abb740a7f4e0513a47e0734ad29d90fff325fd05336"
 }

prisma/migrations/20260910182626_checkout_orders/migration.sql

@@ -0,0 +1,142 @@
+-- CreateEnum
+CREATE TYPE "OrderStatus" AS ENUM ('PENDING_PAYMENT', 'CANCELLED');
+
+-- CreateEnum
+CREATE TYPE "CouponKind" AS ENUM ('FIXED', 'PERCENT');
+
+-- AlterTable
+ALTER TABLE "stock_reservations" ADD COLUMN     "order_id" UUID;
+
+-- CreateTable
+CREATE TABLE "carts" (
+    "id" UUID NOT NULL,
+    "organization_id" UUID NOT NULL,
+    "user_id" UUID NOT NULL,
+    "version" INTEGER NOT NULL DEFAULT 0,
+
+    CONSTRAINT "carts_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateTable
+CREATE TABLE "cart_lines" (
+    "id" UUID NOT NULL,
+    "cart_id" UUID NOT NULL,
+    "organization_id" UUID NOT NULL,
+    "variant_id" UUID NOT NULL,
+    "quantity" INTEGER NOT NULL,
+
+    CONSTRAINT "cart_lines_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateTable
+CREATE TABLE "coupons" (
+    "id" UUID NOT NULL,
+    "organization_id" UUID NOT NULL,
+    "code" VARCHAR(40) NOT NULL,
+    "kind" "CouponKind" NOT NULL,
+    "currency" CHAR(3) NOT NULL,
+    "amount" DECIMAL(12,2),
+    "percent_bps" INTEGER,
+    "minimum_subtotal" DECIMAL(12,2) NOT NULL DEFAULT 0,
+    "max_uses" INTEGER NOT NULL,
+    "per_user_limit" INTEGER NOT NULL,
+    "starts_at" TIMESTAMPTZ(3) NOT NULL,
+    "ends_at" TIMESTAMPTZ(3) NOT NULL,
+    "active" BOOLEAN NOT NULL DEFAULT true,
+
+    CONSTRAINT "coupons_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateTable
+CREATE TABLE "orders" (
+    "id" UUID NOT NULL,
+    "organization_id" UUID NOT NULL,
+    "user_id" UUID NOT NULL,
+    "status" "OrderStatus" NOT NULL DEFAULT 'PENDING_PAYMENT',
+    "currency" CHAR(3) NOT NULL,
+    "subtotal" DECIMAL(16,2) NOT NULL,
+    "discount" DECIMAL(16,2) NOT NULL,
+    "merchandise_total" DECIMAL(16,2) NOT NULL,
+    "address_snapshot" JSONB NOT NULL,
+    "coupon_snapshot" JSONB,
+    "coupon_id" UUID,
+    "idempotency_key" UUID NOT NULL,
+    "request_hash" CHAR(64) NOT NULL,
+    "expires_at" TIMESTAMPTZ(3) NOT NULL,
+    "created_at" TIMESTAMPTZ(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+
+    CONSTRAINT "orders_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateTable
+CREATE TABLE "order_lines" (
+    "id" UUID NOT NULL,
+    "order_id" UUID NOT NULL,
+    "organization_id" UUID NOT NULL,
+    "variant_id" UUID NOT NULL,
+    "sku" VARCHAR(64) NOT NULL,
+    "product_name" VARCHAR(160) NOT NULL,
+    "variant_name" VARCHAR(160) NOT NULL,
+    "quantity" INTEGER NOT NULL,
+    "unit_price" DECIMAL(12,2) NOT NULL,
+    "line_total" DECIMAL(16,2) NOT NULL,
+
+    CONSTRAINT "order_lines_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateIndex
+CREATE UNIQUE INDEX "carts_user_id_organization_id_key" ON "carts"("user_id", "organization_id");
+
+-- CreateIndex
+CREATE UNIQUE INDEX "carts_id_organization_id_key" ON "carts"("id", "organization_id");
+
+-- CreateIndex
+CREATE UNIQUE INDEX "cart_lines_cart_id_variant_id_key" ON "cart_lines"("cart_id", "variant_id");
+
+-- CreateIndex
+CREATE UNIQUE INDEX "coupons_organization_id_code_key" ON "coupons"("organization_id", "code");
+
+-- CreateIndex
+CREATE UNIQUE INDEX "coupons_id_organization_id_key" ON "coupons"("id", "organization_id");
+
+-- CreateIndex
+CREATE INDEX "orders_organization_id_user_id_created_at_id_idx" ON "orders"("organization_id", "user_id", "created_at", "id");
+
+-- CreateIndex
+CREATE INDEX "orders_coupon_id_status_expires_at_idx" ON "orders"("coupon_id", "status", "expires_at");
+
+-- CreateIndex
+CREATE UNIQUE INDEX "orders_user_id_organization_id_idempotency_key_key" ON "orders"("user_id", "organization_id", "idempotency_key");
+
+-- CreateIndex
+CREATE UNIQUE INDEX "orders_id_organization_id_key" ON "orders"("id", "organization_id");
+
+-- CreateIndex
+CREATE UNIQUE INDEX "order_lines_order_id_variant_id_key" ON "order_lines"("order_id", "variant_id");
+
+-- AddForeignKey
+ALTER TABLE "carts" ADD CONSTRAINT "carts_user_id_organization_id_fkey" FOREIGN KEY ("user_id", "organization_id") REFERENCES "users"("id", "organization_id") ON DELETE RESTRICT ON UPDATE CASCADE;
+
+-- AddForeignKey
+ALTER TABLE "cart_lines" ADD CONSTRAINT "cart_lines_cart_id_organization_id_fkey" FOREIGN KEY ("cart_id", "organization_id") REFERENCES "carts"("id", "organization_id") ON DELETE CASCADE ON UPDATE CASCADE;
+
+-- AddForeignKey
+ALTER TABLE "cart_lines" ADD CONSTRAINT "cart_lines_variant_id_organization_id_fkey" FOREIGN KEY ("variant_id", "organization_id") REFERENCES "product_variants"("id", "organization_id") ON DELETE RESTRICT ON UPDATE CASCADE;
+
+-- AddForeignKey
+ALTER TABLE "coupons" ADD CONSTRAINT "coupons_organization_id_fkey" FOREIGN KEY ("organization_id") REFERENCES "organizations"("id") ON DELETE RESTRICT ON UPDATE CASCADE;
+
+-- AddForeignKey
+ALTER TABLE "orders" ADD CONSTRAINT "orders_user_id_organization_id_fkey" FOREIGN KEY ("user_id", "organization_id") REFERENCES "users"("id", "organization_id") ON DELETE RESTRICT ON UPDATE CASCADE;
+
+-- AddForeignKey
+ALTER TABLE "orders" ADD CONSTRAINT "orders_coupon_id_organization_id_fkey" FOREIGN KEY ("coupon_id", "organization_id") REFERENCES "coupons"("id", "organization_id") ON DELETE RESTRICT ON UPDATE CASCADE;
+
+-- AddForeignKey
+ALTER TABLE "order_lines" ADD CONSTRAINT "order_lines_order_id_organization_id_fkey" FOREIGN KEY ("order_id", "organization_id") REFERENCES "orders"("id", "organization_id") ON DELETE RESTRICT ON UPDATE CASCADE;
+
+-- AddForeignKey
+ALTER TABLE "order_lines" ADD CONSTRAINT "order_lines_variant_id_organization_id_fkey" FOREIGN KEY ("variant_id", "organization_id") REFERENCES "product_variants"("id", "organization_id") ON DELETE RESTRICT ON UPDATE CASCADE;
+
+-- AddForeignKey
+ALTER TABLE "stock_reservations" ADD CONSTRAINT "stock_reservations_order_id_organization_id_fkey" FOREIGN KEY ("order_id", "organization_id") REFERENCES "orders"("id", "organization_id") ON DELETE RESTRICT ON UPDATE CASCADE;

prisma/migrations/20260910182800_checkout_integrity/migration.sql

@@ -0,0 +1,8 @@
+-- DropForeignKey
+ALTER TABLE "stock_reservations" DROP CONSTRAINT "stock_reservations_order_id_organization_id_fkey";
+
+-- CreateIndex
+CREATE UNIQUE INDEX "orders_id_user_id_organization_id_key" ON "orders"("id", "user_id", "organization_id");
+
+-- AddForeignKey
+ALTER TABLE "stock_reservations" ADD CONSTRAINT "stock_reservations_order_id_user_id_organization_id_fkey" FOREIGN KEY ("order_id", "user_id", "organization_id") REFERENCES "orders"("id", "user_id", "organization_id") ON DELETE RESTRICT ON UPDATE CASCADE;

prisma/migrations/20260910183016_checkout_snapshot_guards/migration.sql

@@ -0,0 +1,73 @@
+ALTER TABLE carts ADD CONSTRAINT cart_version_nonnegative CHECK (version >= 0);
+ALTER TABLE cart_lines ADD CONSTRAINT cart_quantity_bounds CHECK (quantity BETWEEN 1 AND 100);
+ALTER TABLE coupons ADD CONSTRAINT coupon_rule_valid CHECK (
+  (kind = 'FIXED' AND amount IS NOT NULL AND amount > 0 AND percent_bps IS NULL)
+  OR (kind = 'PERCENT' AND amount IS NULL AND percent_bps BETWEEN 1 AND 10000 AND percent_bps IS NOT NULL)
+);
+ALTER TABLE coupons ADD CONSTRAINT coupon_limits_valid CHECK (
+  minimum_subtotal >= 0 AND max_uses > 0 AND per_user_limit > 0 AND per_user_limit <= max_uses
+  AND ends_at > starts_at AND code ~ '^[A-Z0-9][A-Z0-9_-]{0,39}$'
+  AND currency IN ('INR', 'USD', 'EUR', 'GBP')
+);
+ALTER TABLE orders ADD CONSTRAINT order_totals_valid CHECK (
+  subtotal > 0 AND discount >= 0 AND discount <= subtotal
+  AND merchandise_total = subtotal - discount AND expires_at > created_at
+);
+ALTER TABLE order_lines ADD CONSTRAINT order_line_totals_valid CHECK (
+  quantity BETWEEN 1 AND 100 AND unit_price > 0 AND line_total = unit_price * quantity
+);
+
+CREATE FUNCTION protect_order_snapshot() RETURNS trigger LANGUAGE plpgsql AS $$
+BEGIN
+  IF TG_OP = 'DELETE' THEN RAISE EXCEPTION 'Orders cannot be deleted'; END IF;
+  IF (to_jsonb(NEW) - 'status') IS DISTINCT FROM (to_jsonb(OLD) - 'status') THEN
+    RAISE EXCEPTION 'Order snapshots are immutable';
+  END IF;
+  IF OLD.status = 'CANCELLED' AND NEW.status <> 'CANCELLED' THEN
+    RAISE EXCEPTION 'Cancelled orders cannot be reopened';
+  END IF;
+  RETURN NEW;
+END;
+$$;
+CREATE TRIGGER orders_snapshot_immutable BEFORE UPDATE OR DELETE ON orders
+FOR EACH ROW EXECUTE FUNCTION protect_order_snapshot();
+
+CREATE FUNCTION protect_order_line() RETURNS trigger LANGUAGE plpgsql AS $$
+BEGIN
+  RAISE EXCEPTION 'Order lines are immutable';
+END;
+$$;
+CREATE TRIGGER order_lines_immutable BEFORE UPDATE OR DELETE ON order_lines
+FOR EACH ROW EXECUTE FUNCTION protect_order_line();
+
+CREATE FUNCTION protect_coupon_rules() RETURNS trigger LANGUAGE plpgsql AS $$
+BEGIN
+  IF (to_jsonb(NEW) - 'active') IS DISTINCT FROM (to_jsonb(OLD) - 'active') THEN
+    RAISE EXCEPTION 'Create a new coupon to change discount rules';
+  END IF;
+  RETURN NEW;
+END;
+$$;
+CREATE TRIGGER coupon_rules_immutable BEFORE UPDATE ON coupons
+FOR EACH ROW EXECUTE FUNCTION protect_coupon_rules();
+
+CREATE FUNCTION protect_order_reservation() RETURNS trigger LANGUAGE plpgsql AS $$
+BEGIN
+  IF OLD.order_id IS NOT NULL THEN
+    IF TG_OP = 'DELETE' THEN RAISE EXCEPTION 'Order reservations cannot be deleted'; END IF;
+    IF (to_jsonb(NEW) - 'status') IS DISTINCT FROM (to_jsonb(OLD) - 'status') THEN
+      RAISE EXCEPTION 'Order reservation allocation is immutable';
+    END IF;
+  END IF;
+  IF TG_OP = 'DELETE' THEN RETURN OLD; END IF;
+  RETURN NEW;
+END;
+$$;
+CREATE TRIGGER order_reservation_immutable BEFORE UPDATE OR DELETE ON stock_reservations
+FOR EACH ROW EXECUTE FUNCTION protect_order_reservation();
+
+UPDATE roles SET permissions = ARRAY(
+  SELECT DISTINCT permission FROM unnest(permissions || ARRAY[
+    'coupons.manage', 'orders.read', 'orders.manage'
+  ]::text[]) AS permission ORDER BY permission
+) WHERE is_system = true;

prisma/migrations/20260910184357_order_reconciliation/migration.sql

@@ -0,0 +1,23 @@
+-- Deferred reconciliation permits nested line creation in the same transaction
+-- while preventing incomplete orders or later additions to an existing snapshot.
+CREATE FUNCTION reconcile_order_lines() RETURNS trigger LANGUAGE plpgsql AS $$
+DECLARE
+  target_order UUID;
+  expected NUMERIC;
+  actual NUMERIC;
+BEGIN
+  IF TG_TABLE_NAME = 'orders' THEN target_order := NEW.id;
+  ELSE target_order := NEW.order_id;
+  END IF;
+  SELECT subtotal INTO expected FROM orders WHERE id = target_order;
+  SELECT COALESCE(SUM(line_total), 0) INTO actual FROM order_lines WHERE order_id = target_order;
+  IF expected IS DISTINCT FROM actual THEN
+    RAISE EXCEPTION 'Order subtotal does not match lines';
+  END IF;
+  RETURN NULL;
+END;
+$$;
+CREATE CONSTRAINT TRIGGER orders_reconcile_lines AFTER INSERT ON orders
+DEFERRABLE INITIALLY DEFERRED FOR EACH ROW EXECUTE FUNCTION reconcile_order_lines();
+CREATE CONSTRAINT TRIGGER order_lines_reconcile_total AFTER INSERT ON order_lines
+DEFERRABLE INITIALLY DEFERRED FOR EACH ROW EXECUTE FUNCTION reconcile_order_lines();

prisma/schema.prisma

@@ -22,6 +22,7 @@ model Organization {
   products Product[]
   catalogGroups CatalogGroup[]
   warehouses Warehouse[]
+  coupons Coupon[]
   @@map("organizations")
 }
 model User {
@@ -41,6 +42,8 @@ model User {
   addresses Address[]
   stockEntries StockLedger[]
   stockReservations StockReservation[]
+  carts Cart[]
+  orders Order[]
   @@unique([organizationId, email])
   @@unique([id, organizationId])
   @@index([organizationId, createdAt, id])