diff --git a/src/api/schemas/analyze.ts b/src/api/schemas/analyze.ts
new file mode 100644
index 0000000..fa8e39d
--- /dev/null
+++ b/src/api/schemas/analyze.ts
@@ -0,0 +1,9 @@
+import { z } from "zod";
+export const NamedSchema = z.object({ name: z.string(), count: z.number(), total: z.string() });
+export const MonthSchema = z.object({ month: z.string(), income: z.string(), expense: z.string() });
+export const AnalyzeSchema = z.object({ from: z.string(), to: z.string(), income: z.string(), expense: z.string(),
+  discretionaryExpense: z.string().nullish(), net: z.string(), months: z.array(MonthSchema).nullish(),
+  expenseCategories: z.array(NamedSchema).nullish(), incomePayees: z.array(NamedSchema).nullish(),
+  expensePayees: z.array(NamedSchema).nullish() });
+export type Named = z.infer<typeof NamedSchema>;
+export type Analyze = z.infer<typeof AnalyzeSchema>;
diff --git a/src/api/schemas/budget.ts b/src/api/schemas/budget.ts
new file mode 100644
index 0000000..80c1ae5
--- /dev/null
+++ b/src/api/schemas/budget.ts
@@ -0,0 +1,13 @@
+import { z } from "zod";
+export const LimitRowSchema = z.object({ category: z.string(), spent: z.string(), limit: z.string() });
+export const HorizonReportSchema = z.object({ overallSpent: z.string(), overallLimit: z.string(), rows: z.array(LimitRowSchema) });
+export const CategoryLimitSchema = z.object({ name: z.string(), day: z.string(), week: z.string(), month: z.string() });
+export const SavingsGoalSchema = z.object({ name: z.string(), target: z.string(), monthlyContribution: z.string(),
+  accountId: z.number(), accountName: z.string(), saved: z.string(), targetDate: z.string() });
+export const BudgetSchema = z.object({ dayLimit: z.string(), weekLimit: z.string(), monthLimit: z.string(),
+  plannedIncome: z.string(), plannedIncomeManual: z.string(), loanObligations: z.string(),
+  savingsContributions: z.string().nullish(), subscriptionContributions: z.string().nullish(),
+  availableIncome: z.string(), categories: z.array(CategoryLimitSchema), savingsGoals: z.array(SavingsGoalSchema).nullish(),
+  report: z.object({ day: HorizonReportSchema, week: HorizonReportSchema, month: HorizonReportSchema }) });
+export type Budget = z.infer<typeof BudgetSchema>;
+export type SavingsGoal = z.infer<typeof SavingsGoalSchema>;
diff --git a/src/api/schemas/category.ts b/src/api/schemas/category.ts
new file mode 100644
index 0000000..197db2e
--- /dev/null
+++ b/src/api/schemas/category.ts
@@ -0,0 +1,8 @@
+import { z } from "zod";
+export const CategorySchema = z.object({
+  name: z.string(),
+  kind: z.string(),
+  depth: z.number(),
+  icon: z.string().nullish(),
+});
+export type Category = z.infer<typeof CategorySchema>;
diff --git a/src/api/schemas/connection.ts b/src/api/schemas/connection.ts
new file mode 100644
index 0000000..50d9c3c
--- /dev/null
+++ b/src/api/schemas/connection.ts
@@ -0,0 +1,7 @@
+import { z } from "zod";
+export const ConnectionSchema = z.object({
+  bank: z.string(),
+  username: z.string(),
+  courierManaged: z.boolean(),
+});
+export type Connection = z.infer<typeof ConnectionSchema>;
diff --git a/src/api/schemas/index.ts b/src/api/schemas/index.ts
new file mode 100644
index 0000000..779da1a
--- /dev/null
+++ b/src/api/schemas/index.ts
@@ -0,0 +1,11 @@
+export * from "./networth";
+export * from "./analyze";
+export * from "./budget";
+export * from "./transaction";
+export * from "./lending";
+export * from "./settings";
+export * from "./connection";
+export * from "./category";
+export * from "./subscription";
+export * from "./manualAsset";
+export * from "./user";
diff --git a/src/api/schemas/lending.ts b/src/api/schemas/lending.ts
new file mode 100644
index 0000000..a94d625
--- /dev/null
+++ b/src/api/schemas/lending.ts
@@ -0,0 +1,7 @@
+import { z } from "zod";
+export const LendingRepaymentSchema = z.object({ id: z.number(), amount: z.string(), paidOn: z.string(),
+  note: z.string(), txnId: z.number().nullish() });
+export const LendingSchema = z.object({ id: z.number(), person: z.string(), principal: z.string(), lentOn: z.string(),
+  dueOn: z.string(), note: z.string(), repaid: z.string(), remaining: z.string(), status: z.string(), overdue: z.boolean(),
+  txnId: z.number().nullish(), repayments: z.array(LendingRepaymentSchema) });
+export type Lending = z.infer<typeof LendingSchema>;
diff --git a/src/api/schemas/manualAsset.ts b/src/api/schemas/manualAsset.ts
new file mode 100644
index 0000000..3fe6b55
--- /dev/null
+++ b/src/api/schemas/manualAsset.ts
@@ -0,0 +1,50 @@
+import { z } from "zod";
+
+export const ManualAssetSchema = z.object({
+  name: z.string(),
+  category: z.string(),
+  value: z.string(),
+  acquiredValue: z.string(),
+  currency: z.string(),
+  condition: z.string(),
+  isLiability: z.boolean(),
+  change: z.string(),
+});
+export type ManualAsset = z.infer<typeof ManualAssetSchema>;
+
+export const AssetPointSchema = z.object({
+  value: z.string(),
+  recordedAt: z.string(),
+  low: z.string().nullish(),
+  high: z.string().nullish(),
+  count: z.number().nullish(),
+  source: z.string().nullish(),
+  kind: z.string().nullish(),
+});
+export type AssetPoint = z.infer<typeof AssetPointSchema>;
+
+export const ListingFieldSchema = z.object({
+  name: z.string(),
+  value: z.string(),
+});
+export type ListingField = z.infer<typeof ListingFieldSchema>;
+
+export const AssetListingSchema = z.object({
+  title: z.string(),
+  price: z.string(),
+  url: z.string(),
+  description: z.string().nullish(),
+  fields: z.array(ListingFieldSchema).nullish(),
+  images: z.array(z.string()).nullish(),
+  source: z.string().nullish(),
+});
+export type AssetListing = z.infer<typeof AssetListingSchema>;
+
+export const RevalueResultSchema = z.object({
+  value: z.string(),
+  low: z.string(),
+  high: z.string(),
+  source: z.string(),
+  count: z.number(),
+});
+export type RevalueResult = z.infer<typeof RevalueResultSchema>;
diff --git a/src/api/schemas/networth.ts b/src/api/schemas/networth.ts
new file mode 100644
index 0000000..8abe012
--- /dev/null
+++ b/src/api/schemas/networth.ts
@@ -0,0 +1,7 @@
+import { z } from "zod";
+export const AccountSchema = z.object({ accountId: z.number(), bank: z.string(), accountNumber: z.string(),
+  currency: z.string(), isLiability: z.boolean(), balance: z.string(), asOf: z.string().nullish() });
+export const NetWorthSchema = z.object({ assets: z.string(), liabilities: z.string(), total: z.string(),
+  accounts: z.array(AccountSchema).nullish() });
+export type Account = z.infer<typeof AccountSchema>;
+export type NetWorth = z.infer<typeof NetWorthSchema>;
diff --git a/src/api/schemas/schemas.test.ts b/src/api/schemas/schemas.test.ts
new file mode 100644
index 0000000..2d23d0c
--- /dev/null
+++ b/src/api/schemas/schemas.test.ts
@@ -0,0 +1,12 @@
+import { describe, it, expect } from "vitest";
+import { NetWorthSchema, AnalyzeSchema, BudgetSchema, TxnSchema, LendingSchema } from "./index";
+import * as fx from "../../test/fixtures";
+
+describe("schemas parse backend fixtures", () => {
+  it("networth", () => expect(() => NetWorthSchema.parse(fx.netWorth)).not.toThrow());
+  it("analyze", () => expect(() => AnalyzeSchema.parse(fx.analyzeMonth)).not.toThrow());
+  it("budget", () => expect(() => BudgetSchema.parse(fx.budget)).not.toThrow());
+  it("transaction", () => expect(() => TxnSchema.parse(fx.txn)).not.toThrow());
+  it("lending", () => expect(() => LendingSchema.parse(fx.lending)).not.toThrow());
+  it("rejects wrong shape", () => expect(() => NetWorthSchema.parse({})).toThrow());
+});
diff --git a/src/api/schemas/settings.ts b/src/api/schemas/settings.ts
new file mode 100644
index 0000000..63bdb53
--- /dev/null
+++ b/src/api/schemas/settings.ts
@@ -0,0 +1,11 @@
+import { z } from "zod";
+export const SettingsSchema = z.object({
+  holderName: z.string(),
+  employer: z.string(),
+  salaryKeywords: z.array(z.string()),
+  payDays: z.array(z.number()),
+  ownAccounts: z.array(z.string()),
+  peerAccounts: z.array(z.string()),
+  hideAmounts: z.boolean().nullish(),
+});
+export type Settings = z.infer<typeof SettingsSchema>;
diff --git a/src/api/schemas/subscription.ts b/src/api/schemas/subscription.ts
new file mode 100644
index 0000000..be49e88
--- /dev/null
+++ b/src/api/schemas/subscription.ts
@@ -0,0 +1,15 @@
+import { z } from "zod";
+// Wire JSON field is "id" (Swift-side property name is `subId`, mapped via
+// CodingKeys); the schema key stays "id" to match the actual JSON payload.
+export const SubscriptionSchema = z.object({
+  label: z.string(),
+  amount: z.string(),
+  monthly: z.string(),
+  cadence: z.string(),
+  nextDue: z.string().nullish(),
+  matchKey: z.string().nullish(),
+  id: z.number().nullish(),
+  manual: z.boolean().nullish(),
+  category: z.string().nullish(),
+});
+export type Subscription = z.infer<typeof SubscriptionSchema>;
diff --git a/src/api/schemas/transaction.ts b/src/api/schemas/transaction.ts
new file mode 100644
index 0000000..b9124af
--- /dev/null
+++ b/src/api/schemas/transaction.ts
@@ -0,0 +1,5 @@
+import { z } from "zod";
+export const TxnSchema = z.object({ date: z.string(), amount: z.string(), direction: z.string(), category: z.string(),
+  title: z.string(), balanceAfter: z.string().nullish(), accountId: z.number(), transfer: z.boolean().nullish(),
+  txnId: z.number().nullish(), note: z.string().nullish(), matchKey: z.string().nullish(), salary: z.boolean().nullish() });
+export type Txn = z.infer<typeof TxnSchema>;
diff --git a/src/api/schemas/user.ts b/src/api/schemas/user.ts
new file mode 100644
index 0000000..07f11b1
--- /dev/null
+++ b/src/api/schemas/user.ts
@@ -0,0 +1,13 @@
+import { z } from "zod";
+export const UserSchema = z.object({
+  id: z.number(),
+  email: z.string(),
+  createdAt: z.string(),
+});
+export type User = z.infer<typeof UserSchema>;
+
+export const AuthResponseSchema = z.object({
+  token: z.string(),
+  user: UserSchema,
+});
+export type AuthResponse = z.infer<typeof AuthResponseSchema>;
diff --git a/src/test/fixtures.ts b/src/test/fixtures.ts
new file mode 100644
index 0000000..acd857f
--- /dev/null
+++ b/src/test/fixtures.ts
@@ -0,0 +1,14 @@
+export const netWorth = { assets: "452200", liabilities: "0", total: "452200",
+  accounts: [{ accountId: 1, bank: "khan", accountNumber: "***1", currency: "MNT", isLiability: false, balance: "452200", asOf: "2026-08-01" }] };
+export const analyzeMonth = { from: "2026-08-01", to: "2026-08-31", income: "1345634", expense: "1200000",
+  discretionaryExpense: "800000", net: "145634", months: null, expenseCategories: [{ name: "Хоол", count: 12, total: "23700" }],
+  incomePayees: [{ name: "Цалин", count: 1, total: "1345634" }], expensePayees: [{ name: "худалдан авалт", count: 3, total: "52000" }] };
+export const budget = { dayLimit: "35500", weekLimit: "0", monthLimit: "900000", plannedIncome: "2036795",
+  plannedIncomeManual: "0", loanObligations: "0", savingsContributions: "0", subscriptionContributions: "0", availableIncome: "2036795",
+  categories: [{ name: "Хоол", day: "27000", week: "0", month: "0" }], savingsGoals: [],
+  report: { day: { overallSpent: "15500", overallLimit: "35500", rows: [{ category: "Хоол", spent: "23700", limit: "27000" }] },
+    week: { overallSpent: "0", overallLimit: "0", rows: [] }, month: { overallSpent: "1200000", overallLimit: "900000", rows: [] } } };
+export const txn = { date: "2026-08-01", amount: "52000", direction: "debit", category: "Хоол", title: "худалдан авалт",
+  balanceAfter: "400200", accountId: 1, transfer: false, txnId: 10, note: "", matchKey: "mk1", salary: false };
+export const lending = { id: 1, person: "Бат", principal: "100000", lentOn: "2026-07-01", dueOn: "2026-09-01", note: "",
+  repaid: "40000", remaining: "60000", status: "partial", overdue: false, txnId: null, repayments: [{ id: 1, amount: "40000", paidOn: "2026-08-01", note: "", txnId: null }] };
diff --git a/vitest.config.ts b/vitest.config.ts
new file mode 100644
index 0000000..643bb3b
--- /dev/null
+++ b/vitest.config.ts
@@ -0,0 +1,6 @@
+import { defineConfig } from "vitest/config";
+import react from "@vitejs/plugin-react";
+export default defineConfig({
+  plugins: [react()],
+  test: { environment: "jsdom", setupFiles: ["./vitest.setup.ts"], globals: true },
+});
diff --git a/vitest.setup.ts b/vitest.setup.ts
new file mode 100644
index 0000000..f149f27
--- /dev/null
+++ b/vitest.setup.ts
@@ -0,0 +1 @@
+import "@testing-library/jest-dom/vitest";