Index: app/lib/definitions.ts
===================================================================
--- app/lib/definitions.ts	(revision f20977e9ce332fa167b0afc1e9415dcfc0a4f09a)
+++ app/lib/definitions.ts	(revision c50bceae5ff38339912abb30cbeef03ab744a2e2)
@@ -6,4 +6,56 @@
   user_name: string;
   email: string;
-  password: string;
+  password: string; // hashed
 };
+
+export type TransactionAccount = {
+  transaction_account_id: number;
+  account_name: string | null;
+  balance: string; // DECIMAL comes back as string with `postgres` driver
+  user_id: number | null;
+};
+
+export type Transaction = {
+  transaction_id: number;
+  transaction_name: string | null;
+  amount: string; // DECIMAL -> string
+  net_amount: string | null; // DECIMAL -> string
+  date: string; // TIMESTAMPTZ -> ISO string
+};
+
+export type Tag = {
+  tag_id: number;
+  tag_name: string;
+};
+
+export type TagAssignedToTransaction = {
+  tag_assigned_to_transaction_id: number;
+  transaction_id: number;
+  tag_id: number;
+};
+
+export type TransactionBreakdown = {
+  transaction_breakdown_id: number;
+  transaction_id: number | null;
+  transaction_account_id: number | null;
+  spent_amount: string | null; // DECIMAL -> string
+  earned_amount: string | null; // DECIMAL -> string
+};
+
+/**
+ * Useful “joined/view” shapes (not tables).
+ * These make UI and API code nicer.
+ */
+
+export type TransactionWithTags = Transaction & {
+  tags: Tag[];
+};
+
+export type TransactionAccountWithBreakdowns = TransactionAccount & {
+  breakdowns: TransactionBreakdown[];
+};
+
+export type TransactionBreakdownResolved = TransactionBreakdown & {
+  transaction?: Transaction;
+  transaction_account?: TransactionAccount;
+};