diff --git a/README.md b/README.md
index 24b1e62..0312026 100644
--- a/README.md
+++ b/README.md
@@ -35,6 +35,15 @@ threshold. `npm run test:e2e` пока не является passing gate: Prism
 engine останавливает migration до запуска Jest. Точный статус и trigger
 пересмотра находятся в [remediation registry](../docs/development/audit-remediation.md).
 
+Общий `tsconfig.json` включает `strict: true` и `noFallthroughCasesInSwitch`
+для приложения, тестов и сборок. ESLint запрещает non-null assertions
+(`value!`) и definite-assignment assertions (`field!: Type`).
+Поля DTO, заполняемые вне конструктора, описываются через `declare`:
+входные значения заполняет и проверяет Nest, ответные DTO описывают форму
+возвращаемых объектов. `declare` не создаёт значение и не заменяет
+runtime-валидацию. В обычном коде нужны инициализация или сужение типа
+после проверки значения.
+
 ## Документация
 
 - [Router conventions](.ai/CONVENTIONS.md) и [источники](.ai/SOURCES.md)
diff --git a/eslint.config.mjs b/eslint.config.mjs
index 0abea89..1f292a7 100644
--- a/eslint.config.mjs
+++ b/eslint.config.mjs
@@ -27,6 +27,16 @@ export default tseslint.config(
   {
     rules: {
       '@typescript-eslint/no-explicit-any': 'off',
+      '@typescript-eslint/no-non-null-assertion': 'error',
+      'no-restricted-syntax': [
+        'error',
+        {
+          selector:
+            'PropertyDefinition[definite=true], VariableDeclarator[definite=true]',
+          message:
+            'Definite assignment assertions are forbidden. Initialize owned values; use declare only for externally populated DTO fields.',
+        },
+      ],
       '@typescript-eslint/no-floating-promises': 'warn',
       '@typescript-eslint/no-unsafe-argument': 'warn',
       "prettier/prettier": ["error", { endOfLine: "auto" }],
diff --git a/src/auth/auth.controller.ts b/src/auth/auth.controller.ts
index 3f52899..80079e3 100644
--- a/src/auth/auth.controller.ts
+++ b/src/auth/auth.controller.ts
@@ -28,18 +28,18 @@ const COOKIE_PATH = '/api/v1/auth';
 
 class UserDto {
   @ApiProperty()
-  id: string;
+  declare id: string;
 
   @ApiProperty()
-  email: string;
+  declare email: string;
 }
 
 class AuthenticationDto {
   @ApiProperty()
-  accessToken: string;
+  declare accessToken: string;
 
   @ApiProperty({ type: UserDto })
-  user: UserDto;
+  declare user: UserDto;
 }
 
 @ApiTags('auth')
diff --git a/src/auth/auth.dto.ts b/src/auth/auth.dto.ts
index 3902d0f..7597a05 100644
--- a/src/auth/auth.dto.ts
+++ b/src/auth/auth.dto.ts
@@ -47,11 +47,11 @@ export class CredentialsDto {
     typeof value === 'string' ? value.trim().toLowerCase() : value,
   )
   @Validate(EmailConstraint)
-  email: string;
+  declare email: string;
 
   @ApiProperty({ minLength: 12, maxLength: 72, example: 'a secure password' })
   @IsString()
   @MinLength(12)
   @Validate(PasswordBytesConstraint)
-  password: string;
+  declare password: string;
 }
diff --git a/src/bank-cards/bank-card.dto.ts b/src/bank-cards/bank-card.dto.ts
index e79c7c4..7aa77ad 100644
--- a/src/bank-cards/bank-card.dto.ts
+++ b/src/bank-cards/bank-card.dto.ts
@@ -35,20 +35,20 @@ export const bankOperationKinds = [
 ] as const;
 export type BankOperationKind = (typeof bankOperationKinds)[number];
 export class RubMoneyInputDto {
-  @ApiProperty({ enum: ['RUB'] }) @IsIn(['RUB']) currency: string;
+  @ApiProperty({ enum: ['RUB'] }) @IsIn(['RUB']) declare currency: string;
   @ApiProperty({ pattern: '^-?[0-9]+(\\.[0-9]{1,2})?$' })
   @IsString()
   @Matches(/^-?\d+(\.\d{1,2})?$/)
-  value: string;
+  declare value: string;
 }
 export class CreateBankCardDto {
-  @ApiProperty({ format: 'uuid' }) @IsUUID() id: string;
+  @ApiProperty({ format: 'uuid' }) @IsUUID() declare id: string;
   @ApiProperty({ minLength: 1, maxLength: 100 })
   @Transform(trim)
   @IsString()
   @MinLength(1)
   @MaxLength(100)
-  name: string;
+  declare name: string;
   @ApiPropertyOptional({ type: String, nullable: true, maxLength: 100 })
   @IsOptional()
   @Transform(trim)
@@ -67,17 +67,17 @@ export class CreateBankCardDto {
   @IsDefined()
   @ValidateNested()
   @Type(() => RubMoneyInputDto)
-  openingBalance: MoneyDto;
+  declare openingBalance: MoneyDto;
   @ApiProperty({ format: 'date' })
   @IsString()
   @Matches(/^\d{4}-\d{2}-\d{2}$/)
-  openingDate: string;
+  declare openingDate: string;
 }
 export class UpdateBankCardDto extends PartialType(
   OmitType(CreateBankCardDto, ['id'] as const),
   { skipNullProperties: false },
 ) {
-  @ApiProperty({ minimum: 1 }) @IsInt() @Min(1) version: number;
+  @ApiProperty({ minimum: 1 }) @IsInt() @Min(1) declare version: number;
   @ApiPropertyOptional()
   @ValidateIf((_object, value: unknown) => value !== undefined)
   @IsBoolean()
@@ -89,17 +89,17 @@ export class CategoryNameDto {
   @IsString()
   @MinLength(1)
   @MaxLength(80)
-  name: string;
+  declare name: string;
 }
 export class UpdateExpenseCategoryDto extends CategoryNameDto {
-  @ApiProperty({ minimum: 1 }) @IsInt() @Min(1) version: number;
+  @ApiProperty({ minimum: 1 }) @IsInt() @Min(1) declare version: number;
 }
 export class CreateBankOperationDto {
-  @ApiProperty({ format: 'uuid' }) @IsUUID() id: string;
+  @ApiProperty({ format: 'uuid' }) @IsUUID() declare id: string;
   @ApiProperty({ enum: bankOperationKinds })
   @IsIn(bankOperationKinds)
-  kind: BankOperationKind;
-  @ApiProperty({ format: 'uuid' }) @IsUUID() cardId: string;
+  declare kind: BankOperationKind;
+  @ApiProperty({ format: 'uuid' }) @IsUUID() declare cardId: string;
   @ApiPropertyOptional({ format: 'uuid' })
   @ValidateIf((_object, value: unknown) => value !== undefined)
   @IsUUID()
@@ -116,11 +116,11 @@ export class CreateBankOperationDto {
   @IsDefined()
   @ValidateNested()
   @Type(() => RubMoneyInputDto)
-  amount: MoneyDto;
+  declare amount: MoneyDto;
   @ApiProperty({ format: 'date' })
   @IsString()
   @Matches(/^\d{4}-\d{2}-\d{2}$/)
-  date: string;
+  declare date: string;
   @ApiPropertyOptional({ maxLength: 500 })
   @ValidateIf((_object, value: unknown) => value !== undefined)
   @IsString()
@@ -131,7 +131,7 @@ export class UpdateBankOperationDto extends PartialType(
   OmitType(CreateBankOperationDto, ['id'] as const),
   { skipNullProperties: false },
 ) {
-  @ApiProperty({ minimum: 1 }) @IsInt() @Min(1) version: number;
+  @ApiProperty({ minimum: 1 }) @IsInt() @Min(1) declare version: number;
 }
 export class BankCardsQueryDto {
   @ApiPropertyOptional({ enum: ['true', 'false'] })
@@ -192,68 +192,76 @@ export class BankVersionQueryDto {
   @Type(() => Number)
   @IsInt()
   @Min(1)
-  version: number;
+  declare version: number;
 }
 export class ExpenseCategoryDto {
-  @ApiProperty({ type: String }) id: string;
-  @ApiProperty({ type: String }) name: string;
-  @ApiProperty({ type: Boolean }) isDefault: boolean;
-  @ApiProperty({ type: Number }) version: number;
+  @ApiProperty({ type: String }) declare id: string;
+  @ApiProperty({ type: String }) declare name: string;
+  @ApiProperty({ type: Boolean }) declare isDefault: boolean;
+  @ApiProperty({ type: Number }) declare version: number;
 }
 export class BankCardDto {
-  @ApiProperty({ type: String }) id: string;
-  @ApiProperty({ type: String }) name: string;
-  @ApiProperty({ type: String, nullable: true }) bankName: string | null;
-  @ApiProperty({ type: String, nullable: true }) lastFour: string | null;
-  @ApiProperty({ enum: bankPaymentSystems, nullable: true }) paymentSystem:
+  @ApiProperty({ type: String }) declare id: string;
+  @ApiProperty({ type: String }) declare name: string;
+  @ApiProperty({ type: String, nullable: true }) declare bankName:
     string | null;
-  @ApiProperty({ type: MoneyDto }) openingBalance: MoneyDto;
-  @ApiProperty({ type: String }) openingDate: string;
-  @ApiProperty({ type: MoneyDto }) balance: MoneyDto;
-  @ApiProperty({ type: String, nullable: true }) archivedAt: string | null;
-  @ApiProperty({ type: Number }) version: number;
+  @ApiProperty({ type: String, nullable: true }) declare lastFour:
+    string | null;
+  @ApiProperty({ enum: bankPaymentSystems, nullable: true })
+  declare paymentSystem: string | null;
+  @ApiProperty({ type: MoneyDto }) declare openingBalance: MoneyDto;
+  @ApiProperty({ type: String }) declare openingDate: string;
+  @ApiProperty({ type: MoneyDto }) declare balance: MoneyDto;
+  @ApiProperty({ type: String, nullable: true }) declare archivedAt:
+    string | null;
+  @ApiProperty({ type: Number }) declare version: number;
 }
 export class BankOperationDto {
-  @ApiProperty({ type: String }) id: string;
-  @ApiProperty({ enum: bankOperationKinds }) kind: BankOperationKind;
-  @ApiProperty({ type: String }) cardId: string;
-  @ApiProperty({ type: String }) cardName: string;
-  @ApiProperty({ type: String, nullable: true }) targetCardId: string | null;
-  @ApiProperty({ type: String, nullable: true }) targetCardName: string | null;
-  @ApiProperty({ type: String, nullable: true }) categoryId: string | null;
-  @ApiProperty({ type: String, nullable: true }) categoryName: string | null;
-  @ApiProperty({ type: String, nullable: true }) originalExpenseId:
+  @ApiProperty({ type: String }) declare id: string;
+  @ApiProperty({ enum: bankOperationKinds }) declare kind: BankOperationKind;
+  @ApiProperty({ type: String }) declare cardId: string;
+  @ApiProperty({ type: String }) declare cardName: string;
+  @ApiProperty({ type: String, nullable: true }) declare targetCardId:
     string | null;
-  @ApiProperty({ type: MoneyDto }) amount: MoneyDto;
+  @ApiProperty({ type: String, nullable: true }) declare targetCardName:
+    string | null;
+  @ApiProperty({ type: String, nullable: true }) declare categoryId:
+    string | null;
+  @ApiProperty({ type: String, nullable: true }) declare categoryName:
+    string | null;
+  @ApiProperty({ type: String, nullable: true }) declare originalExpenseId:
+    string | null;
+  @ApiProperty({ type: MoneyDto }) declare amount: MoneyDto;
   @ApiProperty({ type: MoneyDto, nullable: true })
-  availableRefund: MoneyDto | null;
-  @ApiProperty({ type: String }) date: string;
-  @ApiProperty({ type: String, nullable: true }) description: string | null;
-  @ApiProperty({ type: Number }) version: number;
-  @ApiProperty({ type: String }) createdAt: string;
+  declare availableRefund: MoneyDto | null;
+  @ApiProperty({ type: String }) declare date: string;
+  @ApiProperty({ type: String, nullable: true }) declare description:
+    string | null;
+  @ApiProperty({ type: Number }) declare version: number;
+  @ApiProperty({ type: String }) declare createdAt: string;
 }
 export class BankOperationsPageDto {
   @ApiProperty({ type: BankOperationDto, isArray: true })
-  items: BankOperationDto[];
-  @ApiProperty({ type: Number }) page: number;
-  @ApiProperty({ type: Number }) total: number;
-  @ApiProperty({ type: Boolean }) hasNext: boolean;
+  declare items: BankOperationDto[];
+  @ApiProperty({ type: Number }) declare page: number;
+  @ApiProperty({ type: Number }) declare total: number;
+  @ApiProperty({ type: Boolean }) declare hasNext: boolean;
 }
 export class BankSummaryCategoryDto {
-  @ApiProperty({ type: String }) categoryId: string;
-  @ApiProperty({ type: String }) categoryName: string;
-  @ApiProperty({ type: MoneyDto }) expenses: MoneyDto;
-  @ApiProperty({ type: MoneyDto }) refunds: MoneyDto;
-  @ApiProperty({ type: MoneyDto }) net: MoneyDto;
+  @ApiProperty({ type: String }) declare categoryId: string;
+  @ApiProperty({ type: String }) declare categoryName: string;
+  @ApiProperty({ type: MoneyDto }) declare expenses: MoneyDto;
+  @ApiProperty({ type: MoneyDto }) declare refunds: MoneyDto;
+  @ApiProperty({ type: MoneyDto }) declare net: MoneyDto;
 }
 export class BankSummaryDto {
   @ApiPropertyOptional({ type: String }) month?: string;
   @ApiPropertyOptional({ format: 'date' }) from?: string;
   @ApiPropertyOptional({ format: 'date' }) to?: string;
-  @ApiProperty({ type: String, nullable: true }) cardId: string | null;
-  @ApiProperty({ type: MoneyDto }) expenses: MoneyDto;
-  @ApiProperty({ type: MoneyDto }) refunds: MoneyDto;
-  @ApiProperty({ type: MoneyDto }) net: MoneyDto;
+  @ApiProperty({ type: String, nullable: true }) declare cardId: string | null;
+  @ApiProperty({ type: MoneyDto }) declare expenses: MoneyDto;
+  @ApiProperty({ type: MoneyDto }) declare refunds: MoneyDto;
+  @ApiProperty({ type: MoneyDto }) declare net: MoneyDto;
   @ApiProperty({ type: BankSummaryCategoryDto, isArray: true })
-  categories: BankSummaryCategoryDto[];
+  declare categories: BankSummaryCategoryDto[];
 }
diff --git a/src/bank-cards/bank-cards.service.spec.ts b/src/bank-cards/bank-cards.service.spec.ts
new file mode 100644
index 0000000..2932736
--- /dev/null
+++ b/src/bank-cards/bank-cards.service.spec.ts
@@ -0,0 +1,45 @@
+jest.mock('../prisma/prisma.service', () => ({ PrismaService: class {} }));
+jest.mock('../../generated/prisma/client', () => ({ Prisma: {} }));
+import { PrismaService } from '../prisma/prisma.service';
+import { BankCardsService } from './bank-cards.service';
+
+describe('bank card summary categories', () => {
+  it('resolves category names and rejects an inconsistent category reference', async () => {
+    const categories = jest
+      .fn()
+      .mockResolvedValue([{ id: 'food', name: 'Продукты' }]);
+    const tx = {
+      bankCardOperation: {
+        findMany: jest.fn().mockResolvedValue([
+          {
+            kind: 'expense',
+            categoryId: 'food',
+            amountKopecks: 123n,
+            date: '2026-09-13',
+            originalExpense: null,
+          },
+        ]),
+      },
+      expenseCategory: { findMany: categories },
+    };
+    const service = new BankCardsService({
+      $transaction: (run: (client: typeof tx) => unknown) => run(tx),
+    } as unknown as PrismaService);
+
+    await expect(
+      service.summary('user', { month: '2026-09' }),
+    ).resolves.toMatchObject({
+      categories: [
+        {
+          categoryId: 'food',
+          categoryName: 'Продукты',
+          net: { value: '1.23' },
+        },
+      ],
+    });
+    categories.mockResolvedValue([]);
+    await expect(service.summary('user', { month: '2026-09' })).rejects.toThrow(
+      'Bank operation category is missing',
+    );
+  });
+});
diff --git a/src/bank-cards/bank-cards.service.ts b/src/bank-cards/bank-cards.service.ts
index ec1d9b0..cd60a10 100644
--- a/src/bank-cards/bank-cards.service.ts
+++ b/src/bank-cards/bank-cards.service.ts
@@ -45,9 +45,9 @@ const seeds = [
   'Развлечения',
   'Другое',
 ];
-const fail = (code = 'BANK_INVALID_INPUT'): never => {
+function fail(code = 'BANK_INVALID_INPUT'): never {
   throw new BadRequestException({ code });
-};
+}
 function periodBounds(query: BankPeriodQueryDto) {
   if (query.month && !query.from && !query.to) {
     const from = `${query.month}-01`;
@@ -67,12 +67,12 @@ function periodBounds(query: BankPeriodQueryDto) {
     return fail();
   return { from: query.from, to: query.to };
 }
-const conflict = (code = 'BANK_VERSION_CONFLICT'): never => {
+function conflict(code = 'BANK_VERSION_CONFLICT'): never {
   throw new ConflictException({ code });
-};
-const missing = (): never => {
+}
+function missing(): never {
   throw new NotFoundException({ code: 'BANK_NOT_FOUND' });
-};
+}
 const fingerprint = (value: unknown) =>
   createHash('sha256')
     .update(
@@ -417,7 +417,7 @@ export class BankCardsService {
       return {
         id,
         name: label,
-        isDefault: row!.seedKey === 'other',
+        isDefault: row.seedKey === 'other',
         version: version + 1,
       };
     });
@@ -464,7 +464,7 @@ export class BankCardsService {
           where: { userId_seedKey: { userId, seedKey: 'other' } },
         });
         if (!category) missing();
-        input.categoryId = category!.id;
+        input.categoryId = category.id;
       }
       if (
         !(await tx.expenseCategory.findFirst({
@@ -476,7 +476,7 @@ export class BankCardsService {
     if (input.kind !== 'refund' && input.originalExpenseId) fail();
     if (input.kind === 'refund') {
       if (!input.originalExpenseId) fail();
-      const source = await this.operation(tx, userId, input.originalExpenseId!);
+      const source = await this.operation(tx, userId, input.originalExpenseId);
       if (
         source.deletedAt ||
         source.kind !== 'expense' ||
@@ -643,9 +643,9 @@ export class BankCardsService {
         userId,
         deletedAt: null,
         OR: [{ cardId: id }, { targetCardId: id }],
-        ...(expenses
-          ? { kind: 'expense' }
-          : { date: { gte: period!.from, lte: period!.to } }),
+        ...(period
+          ? { date: { gte: period.from, lte: period.to } }
+          : { kind: 'expense' }),
       };
       const total = await tx.bankCardOperation.count({ where });
       const rows = await tx.bankCardOperation.findMany({
@@ -695,13 +695,17 @@ export class BankCardsService {
         expenses: rubMoney(totals.expenses),
         refunds: rubMoney(totals.refunds),
         net: rubMoney(totals.net),
-        categories: totals.categories.map((row) => ({
-          categoryId: row.categoryId,
-          categoryName: categories.find((c) => c.id === row.categoryId)!.name,
-          expenses: rubMoney(row.expenses),
-          refunds: rubMoney(row.refunds),
-          net: rubMoney(row.net),
-        })),
+        categories: totals.categories.map((row) => {
+          const category = categories.find((c) => c.id === row.categoryId);
+          if (!category) throw new Error('Bank operation category is missing');
+          return {
+            categoryId: row.categoryId,
+            categoryName: category.name,
+            expenses: rubMoney(row.expenses),
+            refunds: rubMoney(row.refunds),
+            net: rubMoney(row.net),
+          };
+        }),
       };
     });
   }
diff --git a/src/common/decorators/api-safe-error-response.decorator.ts b/src/common/decorators/api-safe-error-response.decorator.ts
index a490415..3b97dca 100644
--- a/src/common/decorators/api-safe-error-response.decorator.ts
+++ b/src/common/decorators/api-safe-error-response.decorator.ts
@@ -8,10 +8,10 @@ import {
 
 export class ProblemDetailsDto {
   @ApiProperty({ example: 401 })
-  status: number;
+  declare status: number;
 
   @ApiProperty({ example: 'UNAUTHORIZED' })
-  code: string;
+  declare code: string;
 
   @ApiProperty({
     required: false,
diff --git a/src/common/dto-validation.spec.ts b/src/common/dto-validation.spec.ts
new file mode 100644
index 0000000..160ddf4
--- /dev/null
+++ b/src/common/dto-validation.spec.ts
@@ -0,0 +1,61 @@
+import { BadRequestException, ValidationPipe } from '@nestjs/common';
+import { CredentialsDto } from '../auth/auth.dto';
+import {
+  CreateBankCardDto,
+  UpdateBankCardDto,
+} from '../bank-cards/bank-card.dto';
+
+describe('DTO validation', () => {
+  const pipe = new ValidationPipe({ transform: true, whitelist: true });
+
+  it('requires credentials and normalizes a valid email', async () => {
+    const metadata = { type: 'body' as const, metatype: CredentialsDto };
+    await expect(pipe.transform({}, metadata)).rejects.toBeInstanceOf(
+      BadRequestException,
+    );
+    await expect(
+      pipe.transform({ email: 'user@example.com' }, metadata),
+    ).rejects.toBeInstanceOf(BadRequestException);
+    await expect(
+      pipe.transform(
+        { email: ' User@Example.com ', password: 'long-enough-password' },
+        metadata,
+      ),
+    ).resolves.toEqual({
+      email: 'user@example.com',
+      password: 'long-enough-password',
+    });
+  });
+
+  it('requires and validates nested money in a new card', async () => {
+    const metadata = { type: 'body' as const, metatype: CreateBankCardDto };
+    const card = {
+      id: '00000000-0000-4000-8000-000000000001',
+      name: 'Everyday',
+      openingDate: '2026-09-13',
+    };
+    for (const openingBalance of [undefined, null, {}, { currency: 'RUB' }]) {
+      await expect(
+        pipe.transform({ ...card, openingBalance }, metadata),
+      ).rejects.toBeInstanceOf(BadRequestException);
+    }
+    const valid = {
+      ...card,
+      openingBalance: { currency: 'RUB', value: '100.00' },
+    };
+    await expect(pipe.transform(valid, metadata)).resolves.toEqual(valid);
+  });
+
+  it('keeps update fields optional while requiring version and rejecting null', async () => {
+    const metadata = { type: 'body' as const, metatype: UpdateBankCardDto };
+    await expect(pipe.transform({}, metadata)).rejects.toBeInstanceOf(
+      BadRequestException,
+    );
+    await expect(
+      pipe.transform({ version: 1, name: null }, metadata),
+    ).rejects.toBeInstanceOf(BadRequestException);
+    await expect(
+      pipe.transform({ version: 1 }, metadata),
+    ).resolves.toMatchObject({ version: 1 });
+  });
+});
diff --git a/src/common/money.dto.ts b/src/common/money.dto.ts
index 1dd816e..b35b82b 100644
--- a/src/common/money.dto.ts
+++ b/src/common/money.dto.ts
@@ -2,8 +2,8 @@ import { ApiProperty } from '@nestjs/swagger';
 
 export class MoneyDto {
   @ApiProperty()
-  currency: string;
+  declare currency: string;
 
   @ApiProperty()
-  value: string;
+  declare value: string;
 }
diff --git a/src/tbank/account-reference.dto.ts b/src/tbank/account-reference.dto.ts
index 591493e..02148ef 100644
--- a/src/tbank/account-reference.dto.ts
+++ b/src/tbank/account-reference.dto.ts
@@ -3,8 +3,8 @@ import { ApiProperty } from '@nestjs/swagger';
 /** Source account of a row in an all-accounts response. */
 export class AccountReferenceDto {
   @ApiProperty()
-  id: string;
+  declare id: string;
 
   @ApiProperty()
-  name: string;
+  declare name: string;
 }
diff --git a/src/tbank/all-accounts.spec.ts b/src/tbank/all-accounts.spec.ts
index 45f5b0b..10f554c 100644
--- a/src/tbank/all-accounts.spec.ts
+++ b/src/tbank/all-accounts.spec.ts
@@ -1,3 +1,4 @@
+import assert from 'node:assert/strict';
 import {
   BadRequestException,
   ConflictException,
@@ -130,6 +131,7 @@ describe('All accounts', () => {
       instrumentUid: 'common',
       limit: 1,
     });
+    assert.ok(first.nextCursor);
     expect(first.items).toHaveLength(1);
     expect(first.items[0].instrumentUid).toBe('common');
     expect(tbank.getOperationsByCursor).toHaveBeenCalledWith(
@@ -143,13 +145,13 @@ describe('All accounts', () => {
       operations.getAll('user', {
         instrumentUid: 'preferred',
         limit: 1,
-        cursor: first.nextCursor!,
+        cursor: first.nextCursor,
       }),
     ).rejects.toBeInstanceOf(BadRequestException);
     const second = await operations.getAll('user', {
       instrumentUid: 'common',
       limit: 1,
-      cursor: first.nextCursor!,
+      cursor: first.nextCursor,
     });
     expect(second.items[0].instrumentUid).toBe('common');
     expect(second.items[0].id).not.toBe(first.items[0].id);
@@ -246,17 +248,19 @@ describe('All accounts', () => {
       },
     );
     const first = await operations.getAll('user', query);
+    assert.ok(first.nextCursor);
     const second = await operations.getAll('user', {
       ...query,
-      cursor: first.nextCursor!,
+      cursor: first.nextCursor,
     });
     const repeated = await operations.getAll('user', {
       ...query,
-      cursor: first.nextCursor!,
+      cursor: first.nextCursor,
     });
+    assert.ok(second.nextCursor);
     const third = await operations.getAll('user', {
       ...query,
-      cursor: second.nextCursor!,
+      cursor: second.nextCursor,
     });
     expect(first.items.map((item) => [item.id, item.account?.id])).toEqual([
       ['same', 'a'],
@@ -312,7 +316,8 @@ describe('All accounts', () => {
       items: [operation('first', 8), operation('last', 4)],
     });
     const first = await operations.getAll('user', query);
-    const next = { ...query, cursor: first.nextCursor! };
+    assert.ok(first.nextCursor);
+    const next = { ...query, cursor: first.nextCursor };
     await expect(operations.getAll('other', next)).rejects.toBeInstanceOf(
       BadRequestException,
     );
diff --git a/src/tbank/bond.dto.ts b/src/tbank/bond.dto.ts
index bd87594..4f8c4b6 100644
--- a/src/tbank/bond.dto.ts
+++ b/src/tbank/bond.dto.ts
@@ -14,39 +14,51 @@ export class BondCandlesQueryDto extends StockCandlesQueryDto {}
 export class BondCandlesDto extends StockCandlesDto {}
 export class BondPositionDto extends StockPositionDto {}
 export class BondDto {
-  @ApiProperty({ format: 'uuid' }) instrumentUid: string;
+  @ApiProperty({ format: 'uuid' }) declare instrumentUid: string;
   @ApiProperty({
     description: 'Unambiguous ticker URL segment, or the exact instrument UID.',
   })
-  slug: string;
-  @ApiProperty() name: string;
-  @ApiProperty({ type: String, nullable: true }) isin: string | null;
-  @ApiProperty({ type: String, nullable: true }) classCode: string | null;
-  @ApiProperty({ type: String, nullable: true }) realExchange: string | null;
-  @ApiProperty({ type: Boolean, nullable: true }) apiTradeAvailable:
+  declare slug: string;
+  @ApiProperty() declare name: string;
+  @ApiProperty({ type: String, nullable: true }) declare isin: string | null;
+  @ApiProperty({ type: String, nullable: true }) declare classCode:
+    string | null;
+  @ApiProperty({ type: String, nullable: true }) declare realExchange:
+    string | null;
+  @ApiProperty({ type: Boolean, nullable: true }) declare apiTradeAvailable:
     boolean | null;
-  @ApiProperty({ type: String, nullable: true }) ticker: string | null;
-  @ApiProperty({ type: String, nullable: true }) logoName: string | null;
-  @ApiProperty({ type: String, nullable: true }) currency: string | null;
-  @ApiProperty({ type: String, nullable: true }) sector: string | null;
-  @ApiProperty({ type: Number, nullable: true }) lot: number | null;
+  @ApiProperty({ type: String, nullable: true }) declare ticker: string | null;
+  @ApiProperty({ type: String, nullable: true }) declare logoName:
+    string | null;
+  @ApiProperty({ type: String, nullable: true }) declare currency:
+    string | null;
+  @ApiProperty({ type: String, nullable: true }) declare sector: string | null;
+  @ApiProperty({ type: Number, nullable: true }) declare lot: number | null;
   @ApiProperty({ type: String, nullable: true, format: 'date-time' })
-  historyFrom: string | null;
-  @ApiProperty({ type: MoneyDto, nullable: true }) nominal: MoneyDto | null;
+  declare historyFrom: string | null;
   @ApiProperty({ type: MoneyDto, nullable: true })
-  initialNominal: MoneyDto | null;
-  @ApiProperty({ type: MoneyDto, nullable: true }) aci: MoneyDto | null;
-  @ApiProperty({ type: String, nullable: true }) maturityDate: string | null;
-  @ApiProperty({ type: String, nullable: true }) callDate: string | null;
-  @ApiProperty({ type: String, nullable: true }) bondType: string | null;
-  @ApiProperty({ type: String, nullable: true }) riskLevel: string | null;
-  @ApiProperty({ type: Number, nullable: true }) couponQuantityPerYear:
+  declare nominal: MoneyDto | null;
+  @ApiProperty({ type: MoneyDto, nullable: true })
+  declare initialNominal: MoneyDto | null;
+  @ApiProperty({ type: MoneyDto, nullable: true }) declare aci: MoneyDto | null;
+  @ApiProperty({ type: String, nullable: true }) declare maturityDate:
+    string | null;
+  @ApiProperty({ type: String, nullable: true }) declare callDate:
+    string | null;
+  @ApiProperty({ type: String, nullable: true }) declare bondType:
+    string | null;
+  @ApiProperty({ type: String, nullable: true }) declare riskLevel:
+    string | null;
+  @ApiProperty({ type: Number, nullable: true }) declare couponQuantityPerYear:
     number | null;
-  @ApiProperty({ type: Boolean, nullable: true }) floatingCoupon:
+  @ApiProperty({ type: Boolean, nullable: true }) declare floatingCoupon:
+    boolean | null;
+  @ApiProperty({ type: Boolean, nullable: true }) declare perpetual:
+    boolean | null;
+  @ApiProperty({ type: Boolean, nullable: true }) declare amortization:
+    boolean | null;
+  @ApiProperty({ type: Boolean, nullable: true }) declare subordinated:
     boolean | null;
-  @ApiProperty({ type: Boolean, nullable: true }) perpetual: boolean | null;
-  @ApiProperty({ type: Boolean, nullable: true }) amortization: boolean | null;
-  @ApiProperty({ type: Boolean, nullable: true }) subordinated: boolean | null;
 }
 
 export class BondSearchResultDto extends BondDto {
@@ -55,89 +67,99 @@ export class BondSearchResultDto extends BondDto {
     nullable: true,
     description: 'Clean price in percent of nominal, not money.',
   })
-  pricePercent: string | null;
-  @ApiProperty({ type: String, nullable: true, format: 'date-time' }) priceAt:
-    string | null;
+  declare pricePercent: string | null;
+  @ApiProperty({ type: String, nullable: true, format: 'date-time' })
+  declare priceAt: string | null;
 }
 export class BondQuoteDto {
-  @ApiProperty({ type: String, nullable: true }) pricePercent: string | null;
+  @ApiProperty({ type: String, nullable: true }) declare pricePercent:
+    string | null;
   @ApiProperty({
     type: MoneyDto,
     nullable: true,
     description:
       'Indicative clean value at the current nominal; no FX conversion.',
   })
-  cleanPrice: MoneyDto | null;
-  @ApiProperty({ type: MoneyDto, nullable: true }) aci: MoneyDto | null;
+  declare cleanPrice: MoneyDto | null;
+  @ApiProperty({ type: MoneyDto, nullable: true }) declare aci: MoneyDto | null;
   @ApiProperty({
     type: MoneyDto,
     nullable: true,
     description:
       'Indicative clean value plus current accrued interest, excluding fees.',
   })
-  dirtyPrice: MoneyDto | null;
-  @ApiProperty({ type: String, nullable: true }) changePercentagePoints:
+  declare dirtyPrice: MoneyDto | null;
+  @ApiProperty({ type: String, nullable: true })
+  declare changePercentagePoints: string | null;
+  @ApiProperty({ type: String, nullable: true }) declare previousCloseDate:
     string | null;
-  @ApiProperty({ type: String, nullable: true }) previousCloseDate:
+  @ApiProperty({ type: String, nullable: true }) declare tradingStatus:
     string | null;
-  @ApiProperty({ type: String, nullable: true }) tradingStatus: string | null;
-  @ApiProperty({ type: String, nullable: true, format: 'date-time' }) priceAt:
-    string | null;
-  @ApiProperty({ type: [String] }) unavailable: string[];
-  @ApiProperty({ format: 'date-time' }) observedAt: string;
+  @ApiProperty({ type: String, nullable: true, format: 'date-time' })
+  declare priceAt: string | null;
+  @ApiProperty({ type: [String] }) declare unavailable: string[];
+  @ApiProperty({ format: 'date-time' }) declare observedAt: string;
 }
 export class BondCouponDto {
-  @ApiProperty({ type: String, nullable: true }) number: string | null;
-  @ApiProperty({ type: String, nullable: true }) paymentDate: string | null;
-  @ApiProperty({ type: String, nullable: true }) recordDate: string | null;
-  @ApiProperty({ type: String, nullable: true }) couponType: string | null;
-  @ApiProperty({ type: Number, nullable: true }) periodDays: number | null;
-  @ApiProperty({ type: MoneyDto, nullable: true }) perBond: MoneyDto | null;
+  @ApiProperty({ type: String, nullable: true }) declare number: string | null;
+  @ApiProperty({ type: String, nullable: true }) declare paymentDate:
+    string | null;
+  @ApiProperty({ type: String, nullable: true }) declare recordDate:
+    string | null;
+  @ApiProperty({ type: String, nullable: true }) declare couponType:
+    string | null;
+  @ApiProperty({ type: Number, nullable: true }) declare periodDays:
+    number | null;
   @ApiProperty({ type: MoneyDto, nullable: true })
-  estimatedAmount: MoneyDto | null;
-  @ApiProperty({ enum: ['upcoming', 'past', 'undated'] }) timing:
+  declare perBond: MoneyDto | null;
+  @ApiProperty({ type: MoneyDto, nullable: true })
+  declare estimatedAmount: MoneyDto | null;
+  @ApiProperty({ enum: ['upcoming', 'past', 'undated'] }) declare timing:
     'upcoming' | 'past' | 'undated';
 }
 export class BondCouponsDto {
-  @ApiProperty({ type: [BondCouponDto] }) coupons: BondCouponDto[];
-  @ApiProperty() from: string;
-  @ApiProperty() to: string;
-  @ApiProperty() observedAt: string;
-  @ApiProperty({ type: String, nullable: true }) positionAt: string | null;
-  @ApiProperty() estimateUnavailable: boolean;
-  @ApiProperty() positionIsStale: boolean;
+  @ApiProperty({ type: [BondCouponDto] }) declare coupons: BondCouponDto[];
+  @ApiProperty() declare from: string;
+  @ApiProperty() declare to: string;
+  @ApiProperty() declare observedAt: string;
+  @ApiProperty({ type: String, nullable: true }) declare positionAt:
+    string | null;
+  @ApiProperty() declare estimateUnavailable: boolean;
+  @ApiProperty() declare positionIsStale: boolean;
 }
 
 export class BondYieldDto {
   @ApiProperty({ description: 'MOEX effective annual yield in percent.' })
-  value: string;
-  @ApiProperty() pricePercent: string;
-  @ApiProperty({ format: 'date' }) date: string;
+  declare value: string;
+  @ApiProperty() declare pricePercent: string;
+  @ApiProperty({ format: 'date' }) declare date: string;
   @ApiProperty({
     type: String,
     nullable: true,
     description: 'MOEX yield target, e.g. MATDATE or OFFERDATE.',
   })
-  dateType: string | null;
-  @ApiProperty({ format: 'date-time' }) tradeAt: string;
+  declare dateType: string | null;
+  @ApiProperty({ format: 'date-time' }) declare tradeAt: string;
 }
 export class BondCreditRatingDto {
-  @ApiProperty({ enum: ['NCR'] }) agency: 'NCR';
-  @ApiProperty({ type: String, nullable: true }) value: string | null;
-  @ApiProperty({ enum: ['active', 'withdrawn'] }) status:
+  @ApiProperty({ enum: ['NCR'] }) declare agency: 'NCR';
+  @ApiProperty({ type: String, nullable: true }) declare value: string | null;
+  @ApiProperty({ enum: ['active', 'withdrawn'] }) declare status:
     'active' | 'withdrawn';
-  @ApiProperty({ format: 'date' }) date: string;
-  @ApiProperty({ format: 'uri' }) sourceUrl: string;
-  @ApiProperty({ format: 'date-time' }) observedAt: string;
+  @ApiProperty({ format: 'date' }) declare date: string;
+  @ApiProperty({ format: 'uri' }) declare sourceUrl: string;
+  @ApiProperty({ format: 'date-time' }) declare observedAt: string;
 }
 export class BondMetricsDto {
   @ApiProperty({ type: BondCreditRatingDto, nullable: true })
-  creditRating: BondCreditRatingDto | null;
-  @ApiProperty({ type: MoneyDto, nullable: true }) coupon: MoneyDto | null;
-  @ApiProperty({ type: String, nullable: true, format: 'date' }) couponDate:
+  declare creditRating: BondCreditRatingDto | null;
+  @ApiProperty({ type: MoneyDto, nullable: true })
+  declare coupon: MoneyDto | null;
+  @ApiProperty({ type: String, nullable: true, format: 'date' })
+  declare couponDate: string | null;
+  @ApiProperty({ type: String, nullable: true }) declare couponType:
     string | null;
-  @ApiProperty({ type: String, nullable: true }) couponType: string | null;
-  @ApiProperty({ type: Number, nullable: true }) couponPeriodDays:
+  @ApiProperty({ type: Number, nullable: true }) declare couponPeriodDays:
     number | null;
   @ApiProperty({
     type: String,
@@ -145,11 +167,11 @@ export class BondMetricsDto {
     description:
       'Next coupon × 365 / period days / indicative clean price × 100. Not yield to maturity.',
   })
-  couponYieldPercent: string | null;
+  declare couponYieldPercent: string | null;
   @ApiProperty({ type: String, nullable: true, format: 'date-time' })
-  couponYieldPriceAt: string | null;
+  declare couponYieldPriceAt: string | null;
   @ApiProperty({ type: BondYieldDto, nullable: true })
-  effectiveYield: BondYieldDto | null;
-  @ApiProperty({ type: [String] }) unavailable: string[];
-  @ApiProperty({ format: 'date-time' }) observedAt: string;
+  declare effectiveYield: BondYieldDto | null;
+  @ApiProperty({ type: [String] }) declare unavailable: string[];
+  @ApiProperty({ format: 'date-time' }) declare observedAt: string;
 }
diff --git a/src/tbank/bond.service.spec.ts b/src/tbank/bond.service.spec.ts
index 310c0a3..68d4b26 100644
--- a/src/tbank/bond.service.spec.ts
+++ b/src/tbank/bond.service.spec.ts
@@ -1,3 +1,4 @@
+import assert from 'node:assert/strict';
 jest.mock('./tbank-access.service', () => ({
   TbankAccessService: class TbankAccessService {},
 }));
@@ -269,7 +270,7 @@ describe('bond market use case', () => {
   });
   it('keeps late metadata responses within their original connection generation', async () => {
     const { service, tbank, changeGeneration } = setup();
-    let resolveOld!: (value: typeof bond) => void;
+    let resolveOld: ((value: typeof bond) => void) | undefined;
     tbank.getBond.mockReturnValueOnce(
       new Promise((resolve) => {
         resolveOld = resolve;
@@ -281,6 +282,7 @@ describe('bond market use case', () => {
     expect(await service.quote('user', 'uid')).toMatchObject({
       cleanPrice: { value: '392.5' },
     });
+    assert.ok(resolveOld);
     resolveOld(bond);
     await oldQuote;
     expect(await service.quote('user', 'uid')).toMatchObject({
@@ -338,6 +340,8 @@ describe('bond market use case', () => {
       { ...bond, uid: 'uid', apiTradeAvailableFlag: true },
       { ...bond, uid: 'second', isin: 'OTHER', ticker: 'OTHER' },
       { ...bond, uid: 'share', instrumentKind: 'INSTRUMENT_TYPE_SHARE' },
+      { ...bond, uid: undefined },
+      { ...bond, uid: '' },
     ];
     tbank.findBonds.mockResolvedValue(listings);
     tbank.getBond.mockImplementation((_token: string, uid: string) =>
diff --git a/src/tbank/bond.service.ts b/src/tbank/bond.service.ts
index b793cca..5be0936 100644
--- a/src/tbank/bond.service.ts
+++ b/src/tbank/bond.service.ts
@@ -42,6 +42,7 @@ import {
 } from './bond.dto';
 
 const dayMs = 86_400_000;
+type IdentifiedBond = TbankBond & { uid: string };
 
 @Injectable()
 export class BondService {
@@ -71,7 +72,7 @@ export class BondService {
             async (bond) =>
               (await optional(
                 () =>
-                  this.bond(userId, connection, bond.uid!)
+                  this.bond(userId, connection, bond.uid)
                     .then(toBond)
                     .catch((error: unknown) => {
                       if (error instanceof NotFoundException)
@@ -87,7 +88,7 @@ export class BondService {
           () =>
             this.tbank.getLastPrices(
               token,
-              bonds.map((bond) => bond.uid!),
+              bonds.map((bond) => bond.uid),
             ),
           'prices',
           [],
@@ -135,11 +136,11 @@ export class BondService {
   async getByTicker(userId: string, ticker: string): Promise<BondDto> {
     const match = await this.tickerMatch(userId, ticker);
     return {
-      ...(await this.get(userId, match.uid!)),
+      ...(await this.get(userId, match.uid)),
       slug: ticker.trim().toUpperCase(),
     };
   }
-  private tickerMatch(userId: string, ticker: string): Promise<TbankBond> {
+  private tickerMatch(userId: string, ticker: string): Promise<IdentifiedBond> {
     const normalized = ticker.trim().toUpperCase();
     return this.cached(userId, `ticker:${normalized}`, async (connection) => {
       const { token } = connection;
@@ -247,6 +248,7 @@ export class BondService {
   metrics(userId: string, uid: string): Promise<BondMetricsDto> {
     return this.cached(userId, `metrics:${uid}`, async (connection) => {
       const instrument = await this.bond(userId, connection, uid);
+      const { ticker, isin, classCode } = instrument;
       const today = moscowDay(new Date().toISOString());
       const from = `${Number(today.slice(0, 4)) - 5}${today.slice(4)}`;
       const to = `${Number(today.slice(0, 4)) + 1}${today.slice(4)}`;
@@ -258,24 +260,15 @@ export class BondService {
           unavailable,
         ),
         optional(() => this.quote(userId, uid), 'quote', unavailable),
-        instrument.ticker && instrument.isin && instrument.classCode
+        ticker && isin && classCode
           ? optional(
-              () =>
-                this.moex.bondYield(
-                  instrument.ticker!,
-                  instrument.isin!,
-                  instrument.classCode!,
-                ),
+              () => this.moex.bondYield(ticker, isin, classCode),
               'yield',
               unavailable,
             )
           : null,
-        instrument.isin
-          ? optional(
-              () => this.ratings.rating(instrument.isin!),
-              'rating',
-              unavailable,
-            )
+        isin
+          ? optional(() => this.ratings.rating(isin), 'rating', unavailable)
           : null,
       ]);
       const next = events
@@ -482,7 +475,7 @@ export class BondService {
     userId: string,
     connection: TbankConnectionContext,
     uid: string,
-  ): Promise<TbankBond> {
+  ): Promise<IdentifiedBond> {
     return this.cachedForConnection(
       userId,
       connection,
@@ -490,7 +483,7 @@ export class BondService {
       async () => {
         const bond = await this.tbank.getBond(connection.token, uid);
         if (!bond || bond.uid !== uid) throw new NotFoundException();
-        return bond;
+        return { ...bond, uid };
       },
     );
   }
@@ -523,11 +516,12 @@ export class BondService {
   }
 }
 
-function selectBonds(found: TbankBond[], query: string): TbankBond[] {
+function selectBonds(found: TbankBond[], query: string): IdentifiedBond[] {
   const seen = new Set<string>();
   return found
     .filter(
-      (bond) => bond.uid && bond.instrumentKind === 'INSTRUMENT_TYPE_BOND',
+      (bond): bond is IdentifiedBond =>
+        Boolean(bond.uid) && bond.instrumentKind === 'INSTRUMENT_TYPE_BOND',
     )
     .sort(
       (a, b) =>
@@ -536,24 +530,24 @@ function selectBonds(found: TbankBond[], query: string): TbankBond[] {
         Number(b.ticker?.toUpperCase() === query.toUpperCase()) -
           Number(a.ticker?.toUpperCase() === query.toUpperCase()) ||
         Number(b.classCode === 'TQOB') - Number(a.classCode === 'TQOB') ||
-        a.uid!.localeCompare(b.uid!),
+        a.uid.localeCompare(b.uid),
     )
     .filter((bond) => {
       // A missing ISIN must not collapse unrelated catalog instruments.
       const key = bond.isin?.trim()
         ? `isin:${bond.isin.trim().toUpperCase()}`
-        : `uid:${bond.uid!}`;
+        : `uid:${bond.uid}`;
       if (seen.has(key)) return false;
       seen.add(key);
       return true;
     });
 }
 
-function toBond(bond: TbankBond): BondDto {
+function toBond(bond: IdentifiedBond): BondDto {
   return {
-    instrumentUid: bond.uid!,
-    slug: bond.uid!,
-    name: bond.name?.trim() || bond.ticker || bond.uid!,
+    instrumentUid: bond.uid,
+    slug: bond.uid,
+    name: bond.name?.trim() || bond.ticker || bond.uid,
     ticker: bond.ticker?.trim() || null,
     isin: bond.isin?.trim() || null,
     classCode: bond.classCode?.trim() || null,
diff --git a/src/tbank/brokerage-account.dto.ts b/src/tbank/brokerage-account.dto.ts
index 868cdbb..dfa4812 100644
--- a/src/tbank/brokerage-account.dto.ts
+++ b/src/tbank/brokerage-account.dto.ts
@@ -3,29 +3,29 @@ import { MoneyDto } from '../common/money.dto';
 
 export class PortfolioSummaryDto {
   @ApiProperty({ type: MoneyDto, isArray: true })
-  totalsByCurrency: MoneyDto[];
+  declare totalsByCurrency: MoneyDto[];
 
   @ApiProperty({
     type: 'integer',
     minimum: 0,
     description: 'Number of non-zero stock positions, not the number of units.',
   })
-  stockPositionCount: number;
+  declare stockPositionCount: number;
 
   @ApiProperty({
     type: 'integer',
     minimum: 0,
     description: 'Number of non-zero bond positions, not the number of units.',
   })
-  bondPositionCount: number;
+  declare bondPositionCount: number;
 }
 
 export class BrokerageAccountDto {
   @ApiProperty()
-  id: string;
+  declare id: string;
 
   @ApiProperty()
-  name: string;
+  declare name: string;
 
   @ApiProperty({
     enum: [
@@ -35,11 +35,11 @@ export class BrokerageAccountDto {
       'MONEY_MARKET_FUND',
     ],
   })
-  type:
+  declare type:
     'BROKERAGE' | 'INDIVIDUAL_INVESTMENT' | 'INVEST_BOX' | 'MONEY_MARKET_FUND';
 
   @ApiProperty({ type: String, nullable: true, format: 'date' })
-  openedOn: string | null;
+  declare openedOn: string | null;
 
   @ApiProperty({ type: PortfolioSummaryDto, nullable: true })
   portfolioSummary?: PortfolioSummaryDto | null;
diff --git a/src/tbank/brokerage-operation.dto.ts b/src/tbank/brokerage-operation.dto.ts
index 169d592..883a409 100644
--- a/src/tbank/brokerage-operation.dto.ts
+++ b/src/tbank/brokerage-operation.dto.ts
@@ -75,64 +75,64 @@ export class BrokerageOperationDto {
   account?: AccountReferenceDto;
 
   @ApiProperty()
-  id: string;
+  declare id: string;
 
   @ApiProperty({ format: 'date-time' })
-  occurredAt: string;
+  declare occurredAt: string;
 
   @ApiProperty()
-  type: string;
+  declare type: string;
 
   @ApiProperty({ enum: operationCategories })
-  category: OperationCategory;
+  declare category: OperationCategory;
 
   @ApiProperty()
-  description: string;
+  declare description: string;
 
   @ApiProperty({ type: String, nullable: true })
-  figi: string | null;
+  declare figi: string | null;
 
   @ApiProperty({ type: String, nullable: true })
-  instrumentUid: string | null;
+  declare instrumentUid: string | null;
 
   @ApiProperty({ type: String, nullable: true })
-  ticker: string | null;
+  declare ticker: string | null;
 
   @ApiProperty({ type: String, nullable: true })
-  instrumentType: string | null;
+  declare instrumentType: string | null;
 
   @ApiProperty({ type: String, nullable: true })
-  logoName: string | null;
+  declare logoName: string | null;
 
   @ApiProperty({ type: MoneyDto, nullable: true })
-  payment: MoneyDto | null;
+  declare payment: MoneyDto | null;
 
   @ApiProperty({ type: String, nullable: true })
-  quantity: string | null;
+  declare quantity: string | null;
 
   @ApiProperty({ type: MoneyDto, nullable: true })
-  price: MoneyDto | null;
+  declare price: MoneyDto | null;
 
   @ApiProperty({ type: MoneyDto, nullable: true })
-  accruedInterest: MoneyDto | null;
+  declare accruedInterest: MoneyDto | null;
 
   @ApiProperty({ type: MoneyDto, nullable: true })
-  commission: MoneyDto | null;
+  declare commission: MoneyDto | null;
 }
 
 export class BrokerageOperationsPageDto {
   @ApiProperty()
-  accountId: string;
+  declare accountId: string;
 
   @ApiProperty({ type: BrokerageOperationDto, isArray: true })
-  items: BrokerageOperationDto[];
+  declare items: BrokerageOperationDto[];
 
   @ApiProperty({ type: String, nullable: true })
-  nextCursor: string | null;
+  declare nextCursor: string | null;
 
   @ApiProperty()
-  hasNext: boolean;
+  declare hasNext: boolean;
 
   @ApiProperty({ format: 'date-time' })
-  observedAt: string;
+  declare observedAt: string;
 }
diff --git a/src/tbank/brokerage-operations.service.ts b/src/tbank/brokerage-operations.service.ts
index fdeddc4..9157b70 100644
--- a/src/tbank/brokerage-operations.service.ts
+++ b/src/tbank/brokerage-operations.service.ts
@@ -222,7 +222,7 @@ export class BrokerageOperationsService {
             left.account.id.localeCompare(right.account.id),
         )[0];
       if (!next) break;
-      items.push(next.pending.shift()!);
+      items.push(...next.pending.splice(0, 1));
     }
     const hasNext = streams.some(
       (stream) => stream.pending.length || !stream.finished,
@@ -262,7 +262,9 @@ export class BrokerageOperationsService {
             : undefined;
         const selected =
           typeof ranges === 'function' ? ranges(accountOpenedAt) : ranges;
-        const pages: BrokerageOperationsPageDto[][] = selected.map(() => []);
+        const pages: {
+          items: (BrokerageOperationDto & { account: AccountReferenceDto })[];
+        }[][] = selected.map(() => []);
         for (const account of accounts) {
           for (const [index, range] of selected.entries()) {
             const collected = await this.collectRange(
@@ -294,7 +296,7 @@ export class BrokerageOperationsService {
                   (left, right) =>
                     Date.parse(right.occurredAt) -
                       Date.parse(left.occurredAt) ||
-                    left.account!.id.localeCompare(right.account!.id),
+                    left.account.id.localeCompare(right.account.id),
                 ),
             },
           ]),
diff --git a/src/tbank/income-analytics.dto.ts b/src/tbank/income-analytics.dto.ts
index 82a8846..91057ae 100644
--- a/src/tbank/income-analytics.dto.ts
+++ b/src/tbank/income-analytics.dto.ts
@@ -19,123 +19,123 @@ export class IncomeAnalyticsQueryDto {
 
 export class IncomePeriodDto {
   @ApiProperty({ format: 'date' })
-  from: string;
+  declare from: string;
 
   @ApiProperty({ format: 'date' })
-  to: string;
+  declare to: string;
 }
 
 export class IncomeCurrencySummaryDto {
   @ApiProperty()
-  currency: string;
+  declare currency: string;
 
   @ApiProperty({ type: MoneyDto })
-  coupon: MoneyDto;
+  declare coupon: MoneyDto;
 
   @ApiProperty({ type: MoneyDto })
-  dividend: MoneyDto;
+  declare dividend: MoneyDto;
 
   @ApiProperty({ type: MoneyDto })
-  total: MoneyDto;
+  declare total: MoneyDto;
 }
 
 export class IncomeSummaryDto {
   @ApiProperty()
-  accountId: string;
+  declare accountId: string;
 
   @ApiProperty({ type: IncomePeriodDto })
-  period: IncomePeriodDto;
+  declare period: IncomePeriodDto;
 
   @ApiProperty({ type: IncomeCurrencySummaryDto, isArray: true })
-  totalsByCurrency: IncomeCurrencySummaryDto[];
+  declare totalsByCurrency: IncomeCurrencySummaryDto[];
 
   @ApiProperty({ format: 'date-time' })
-  calculatedAt: string;
+  declare calculatedAt: string;
 }
 
 export class IncomeComparisonCurrencyDto {
   @ApiProperty()
-  currency: string;
+  declare currency: string;
 
   @ApiProperty({ type: IncomeCurrencySummaryDto })
-  selected: IncomeCurrencySummaryDto;
+  declare selected: IncomeCurrencySummaryDto;
 
   @ApiProperty({ type: IncomeCurrencySummaryDto })
-  compared: IncomeCurrencySummaryDto;
+  declare compared: IncomeCurrencySummaryDto;
 
   @ApiProperty({ type: IncomeCurrencySummaryDto })
-  difference: IncomeCurrencySummaryDto;
+  declare difference: IncomeCurrencySummaryDto;
 }
 
 export class IncomeComparisonDto {
   @ApiProperty({ type: IncomePeriodDto })
-  period: IncomePeriodDto;
+  declare period: IncomePeriodDto;
 
   @ApiProperty({ type: IncomeComparisonCurrencyDto, isArray: true })
-  totalsByCurrency: IncomeComparisonCurrencyDto[];
+  declare totalsByCurrency: IncomeComparisonCurrencyDto[];
 }
 
 export class IncomeBucketDto {
   @ApiProperty({ type: IncomePeriodDto })
-  period: IncomePeriodDto;
+  declare period: IncomePeriodDto;
 
   @ApiProperty({ type: IncomeCurrencySummaryDto, isArray: true })
-  totalsByCurrency: IncomeCurrencySummaryDto[];
+  declare totalsByCurrency: IncomeCurrencySummaryDto[];
 }
 
 export class IncomeInstrumentDto {
   @ApiProperty()
-  key: string;
+  declare key: string;
 
   @ApiProperty({ type: String, nullable: true })
-  figi: string | null;
+  declare figi: string | null;
 
   @ApiProperty({ type: String, nullable: true })
-  instrumentUid: string | null;
+  declare instrumentUid: string | null;
 
   @ApiProperty({ type: String, nullable: true })
-  ticker: string | null;
+  declare ticker: string | null;
 
   @ApiProperty({ type: String, nullable: true })
-  instrumentType: string | null;
+  declare instrumentType: string | null;
 
   @ApiProperty()
-  displayName: string;
+  declare displayName: string;
 
   @ApiProperty({ type: MoneyDto })
-  coupon: MoneyDto;
+  declare coupon: MoneyDto;
 
   @ApiProperty({ type: MoneyDto })
-  dividend: MoneyDto;
+  declare dividend: MoneyDto;
 
   @ApiProperty({ type: MoneyDto })
-  total: MoneyDto;
+  declare total: MoneyDto;
 
   @ApiProperty()
-  receiptCount: number;
+  declare receiptCount: number;
 }
 
 export class IncomeAnalyticsEntryDto extends BrokerageOperationDto {
   @ApiProperty()
-  instrumentKey: string;
+  declare instrumentKey: string;
 }
 
 export class IncomeAnalyticsDto extends IncomeSummaryDto {
   @ApiProperty({ type: IncomeComparisonDto })
-  previous: IncomeComparisonDto;
+  declare previous: IncomeComparisonDto;
 
   @ApiProperty({ type: IncomeComparisonDto, nullable: true })
-  yearComparison: IncomeComparisonDto | null;
+  declare yearComparison: IncomeComparisonDto | null;
 
   @ApiProperty({ enum: ['day', 'week', 'month'] })
-  bucketGranularity: 'day' | 'week' | 'month';
+  declare bucketGranularity: 'day' | 'week' | 'month';
 
   @ApiProperty({ type: IncomeBucketDto, isArray: true })
-  buckets: IncomeBucketDto[];
+  declare buckets: IncomeBucketDto[];
 
   @ApiProperty({ type: IncomeInstrumentDto, isArray: true })
-  instruments: IncomeInstrumentDto[];
+  declare instruments: IncomeInstrumentDto[];
 
   @ApiProperty({ type: IncomeAnalyticsEntryDto, isArray: true })
-  entries: IncomeAnalyticsEntryDto[];
+  declare entries: IncomeAnalyticsEntryDto[];
 }
diff --git a/src/tbank/instrument-metadata.service.spec.ts b/src/tbank/instrument-metadata.service.spec.ts
index 769a43d..f1f03ec 100644
--- a/src/tbank/instrument-metadata.service.spec.ts
+++ b/src/tbank/instrument-metadata.service.spec.ts
@@ -1,3 +1,4 @@
+import assert from 'node:assert/strict';
 import { InstrumentMetadataService } from './instrument-metadata.service';
 import { ServiceUnavailableException } from '@nestjs/common';
 import type { LRUCache } from 'lru-cache';
@@ -178,7 +179,7 @@ describe('InstrumentMetadataService', () => {
   it('isolates in-flight credentials while sharing successful public metadata', async () => {
     const error = new Error('INVALID_TBANK_TOKEN');
     const known = { name: 'Облигация' };
-    let rejectInvalid!: (reason: Error) => void;
+    let rejectInvalid: ((reason: Error) => void) | undefined;
     tbank.getInstrumentByUid.mockImplementation((token: string) =>
       token === 'invalid-token'
         ? new Promise((_resolve, reject) => {
@@ -191,6 +192,7 @@ describe('InstrumentMetadataService', () => {
       service.resolve('invalid-token', 'uid-1', null),
     ).rejects.toBe(error);
     const valid = service.resolve('valid-token', 'uid-1', null);
+    assert.ok(rejectInvalid);
     rejectInvalid(error);
 
     await invalid;
@@ -237,7 +239,7 @@ describe('InstrumentMetadataService', () => {
 
   it('keeps a shared fetch alive after one caller aborts and caches its result', async () => {
     const known = { name: 'Облигация' };
-    let finish!: (value: TbankInstrument) => void;
+    let finish: ((value: TbankInstrument) => void) | undefined;
     tbank.getInstrumentByUid.mockReturnValue(
       new Promise((resolve) => {
         finish = resolve;
@@ -254,6 +256,7 @@ describe('InstrumentMetadataService', () => {
     await expect(aborted).resolves.toBeNull();
 
     const waiting = service.resolve('token', 'uid-1', null);
+    assert.ok(finish);
     finish(known);
 
     await expect(waiting).resolves.toEqual(known);
@@ -265,7 +268,7 @@ describe('InstrumentMetadataService', () => {
   });
 
   it('does not start FIGI lookup after an aborted UID lookup fails later', async () => {
-    let fail!: (reason: Error) => void;
+    let fail: ((reason: Error) => void) | undefined;
     tbank.getInstrumentByUid.mockReturnValue(
       new Promise((_resolve, reject) => {
         fail = reject;
@@ -281,6 +284,7 @@ describe('InstrumentMetadataService', () => {
     controller.abort();
     await expect(result).resolves.toBeNull();
 
+    assert.ok(fail);
     fail(new Error('INVALID_TBANK_TOKEN'));
     await Promise.resolve();
     await Promise.resolve();
diff --git a/src/tbank/instrument-position.ts b/src/tbank/instrument-position.ts
index b083ec0..99735d1 100644
--- a/src/tbank/instrument-position.ts
+++ b/src/tbank/instrument-position.ts
@@ -70,13 +70,16 @@ function cost(position: PortfolioPositionDto): MoneyDto | null {
 }
 function sumComplete(values: (MoneyDto | null)[]): MoneyDto | null {
   const currency = values[0]?.currency;
-  if (!currency || values.some((v) => !v || v.currency !== currency))
+  if (
+    !currency ||
+    !values.every((v): v is MoneyDto => v !== null && v.currency === currency)
+  )
     return null;
   return {
     currency,
     value: formatDecimal(
       values.reduce(
-        (sum, value) => add(sum, decimalFromString(value!.value)),
+        (sum, value) => add(sum, decimalFromString(value.value)),
         decimalFromString('0'),
       ),
     ),
diff --git a/src/tbank/portfolio.dto.ts b/src/tbank/portfolio.dto.ts
index a161bb9..24dd2fa 100644
--- a/src/tbank/portfolio.dto.ts
+++ b/src/tbank/portfolio.dto.ts
@@ -10,10 +10,10 @@ export class PortfolioPositionDto {
   account?: AccountReferenceDto;
 
   @ApiProperty({ type: String, nullable: true })
-  figi: string | null;
+  declare figi: string | null;
 
   @ApiProperty()
-  displayName: string;
+  declare displayName: string;
 
   @ApiProperty({
     enum: [
@@ -28,36 +28,36 @@ export class PortfolioPositionDto {
       'OTHER',
     ],
   })
-  type: string;
+  declare type: string;
 
   @ApiProperty()
-  quantity: string;
+  declare quantity: string;
 
   @ApiProperty({ type: MoneyDto, nullable: true })
-  currentValue: MoneyDto | null;
+  declare currentValue: MoneyDto | null;
 
   @ApiProperty({ type: MoneyDto, nullable: true })
-  averagePurchasePrice: MoneyDto | null;
+  declare averagePurchasePrice: MoneyDto | null;
 
   @ApiProperty({ type: MoneyDto, nullable: true })
-  absoluteReturn: MoneyDto | null;
+  declare absoluteReturn: MoneyDto | null;
 
   @ApiProperty({ type: String, nullable: true })
-  isin: string | null;
+  declare isin: string | null;
 
   @ApiProperty({ type: String, nullable: true })
-  ticker: string | null;
+  declare ticker: string | null;
 
   @ApiProperty({ type: String, nullable: true })
-  logoName: string | null;
+  declare logoName: string | null;
 }
 
 export class PortfolioStructureCategoryDto {
   @ApiProperty({ enum: ['STOCK', 'BOND', 'OTHER', 'CASH'] })
-  type: string;
+  declare type: string;
 
   @ApiProperty({ description: 'Exact known value as a decimal string.' })
-  value: string;
+  declare value: string;
 
   @ApiProperty({
     type: String,
@@ -65,61 +65,61 @@ export class PortfolioStructureCategoryDto {
     description:
       'Percentage including cash, rounded to six decimal places. Null for incomplete, negative or zero-total compositions.',
   })
-  sharePercent: string | null;
+  declare sharePercent: string | null;
 }
 
 export class PortfolioStructureCurrencyDto {
   @ApiProperty()
-  currency: string;
+  declare currency: string;
 
   @ApiProperty()
-  totalValue: string;
+  declare totalValue: string;
 
   @ApiProperty({
     description: 'Any negative constituent, even if netted positive.',
   })
-  hasNegativeValues: boolean;
+  declare hasNegativeValues: boolean;
 
   @ApiProperty({ type: [PortfolioStructureCategoryDto] })
-  categories: PortfolioStructureCategoryDto[];
+  declare categories: PortfolioStructureCategoryDto[];
 }
 
 export class PortfolioUnvaluedCategoryDto {
   @ApiProperty({ enum: ['STOCK', 'BOND', 'OTHER'] })
-  type: string;
+  declare type: string;
 
   @ApiProperty({ minimum: 1 })
-  count: number;
+  declare count: number;
 }
 
 export class PortfolioStructureDto {
   @ApiProperty({ type: [PortfolioStructureCurrencyDto] })
-  currencies: PortfolioStructureCurrencyDto[];
+  declare currencies: PortfolioStructureCurrencyDto[];
 
   @ApiProperty({
     type: [PortfolioUnvaluedCategoryDto],
     description:
       'Positions without current value and known valuation currency. Shares are unavailable across all currencies when nonempty.',
   })
-  unvaluedCategories: PortfolioUnvaluedCategoryDto[];
+  declare unvaluedCategories: PortfolioUnvaluedCategoryDto[];
 }
 
 export class PortfolioDto {
   @ApiProperty({ format: 'date-time' })
-  lastSuccessfulAt: string;
+  declare lastSuccessfulAt: string;
 
   @ApiProperty()
-  isStale: boolean;
+  declare isStale: boolean;
 
   @ApiProperty({ type: MoneyDto, isArray: true })
-  totalsByCurrency: MoneyDto[];
+  declare totalsByCurrency: MoneyDto[];
 
   @ApiProperty({ type: PortfolioPositionDto, isArray: true })
-  positions: PortfolioPositionDto[];
+  declare positions: PortfolioPositionDto[];
 
   @ApiProperty({ type: MoneyDto, isArray: true })
-  cashBalances: MoneyDto[];
+  declare cashBalances: MoneyDto[];
 
   @ApiProperty({ type: PortfolioStructureDto })
-  structure: PortfolioStructureDto;
+  declare structure: PortfolioStructureDto;
 }
diff --git a/src/tbank/portfolio.service.spec.ts b/src/tbank/portfolio.service.spec.ts
index 8b77529..6c9ddad 100644
--- a/src/tbank/portfolio.service.spec.ts
+++ b/src/tbank/portfolio.service.spec.ts
@@ -1,3 +1,4 @@
+import assert from 'node:assert/strict';
 import {
   BadRequestException,
   ConflictException,
@@ -270,7 +271,9 @@ describe('PortfolioService', () => {
     const snapshots = (
       service as never as { snapshots: Map<string, { storedAt: number }> }
     ).snapshots;
-    snapshots.get('user:account')!.storedAt = Date.now() - 30_001;
+    const snapshot = snapshots.get('user:account');
+    assert.ok(snapshot);
+    snapshot.storedAt = Date.now() - 30_001;
     tbank.getPortfolio.mockRejectedValueOnce(
       new ServiceUnavailableException({ code: 'TBANK_UNAVAILABLE' }),
     );
@@ -284,7 +287,9 @@ describe('PortfolioService', () => {
     const snapshots = (
       service as never as { snapshots: Map<string, { storedAt: number }> }
     ).snapshots;
-    snapshots.get('user:account')!.storedAt = Date.now() - 30_001;
+    const snapshot = snapshots.get('user:account');
+    assert.ok(snapshot);
+    snapshot.storedAt = Date.now() - 30_001;
     access.withAccountForConnection.mockRejectedValueOnce(
       new BadRequestException({ code: 'INVALID_TBANK_TOKEN' }),
     );
@@ -298,7 +303,9 @@ describe('PortfolioService', () => {
     const snapshots = (
       service as never as { snapshots: Map<string, { storedAt: number }> }
     ).snapshots;
-    snapshots.get('user:account')!.storedAt = Date.now() - 30_001;
+    const snapshot = snapshots.get('user:account');
+    assert.ok(snapshot);
+    snapshot.storedAt = Date.now() - 30_001;
     generation = 'generation-2';
     tbank.getPortfolio.mockRejectedValueOnce(
       new ServiceUnavailableException({ code: 'TBANK_UNAVAILABLE' }),
@@ -314,7 +321,9 @@ describe('PortfolioService', () => {
     const snapshots = (
       service as never as { snapshots: Map<string, { storedAt: number }> }
     ).snapshots;
-    snapshots.get('user:account')!.storedAt = Date.now() - 30_001;
+    const snapshot = snapshots.get('user:account');
+    assert.ok(snapshot);
+    snapshot.storedAt = Date.now() - 30_001;
     access.withAccountForConnection.mockRejectedValueOnce(
       new ServiceUnavailableException({ code: 'TBANK_UNAVAILABLE' }),
     );
diff --git a/src/tbank/portfolio.service.ts b/src/tbank/portfolio.service.ts
index fe67f17..2013505 100644
--- a/src/tbank/portfolio.service.ts
+++ b/src/tbank/portfolio.service.ts
@@ -222,8 +222,8 @@ export class PortfolioService {
             value: formatDecimal(
               multiply(
                 subtract(
-                  decimal(position.currentPrice!),
-                  decimal(position.averagePositionPrice!),
+                  decimalFromString(currentPrice.value),
+                  decimalFromString(averagePurchasePrice.value),
                 ),
                 quantity,
               ),
diff --git a/src/tbank/stock.dto.ts b/src/tbank/stock.dto.ts
index 275c7c7..8c17353 100644
--- a/src/tbank/stock.dto.ts
+++ b/src/tbank/stock.dto.ts
@@ -19,7 +19,7 @@ export class StockSearchQueryDto {
   @IsString()
   @MinLength(2)
   @MaxLength(80)
-  query: string;
+  declare query: string;
 }
 export class StockTickerParamsDto {
   @ApiProperty({
@@ -31,7 +31,7 @@ export class StockTickerParamsDto {
   @MinLength(1)
   @MaxLength(80)
   @Matches(/^[A-Za-z0-9][A-Za-z0-9._@+-]*$/)
-  ticker: string;
+  declare ticker: string;
 }
 export class StockCandlesQueryDto {
   @ApiPropertyOptional({
@@ -43,108 +43,126 @@ export class StockCandlesQueryDto {
   period?: 'month' | 'halfYear' | 'year' | 'all';
 }
 export class StockDto {
-  @ApiProperty({ format: 'uuid' }) instrumentUid: string;
+  @ApiProperty({ format: 'uuid' }) declare instrumentUid: string;
   @ApiProperty({
     description: 'Unambiguous ticker URL segment, or the exact instrument UID.',
   })
-  slug: string;
-  @ApiProperty() name: string;
-  @ApiProperty({ type: String, nullable: true }) isin: string | null;
-  @ApiProperty({ type: String, nullable: true }) classCode: string | null;
-  @ApiProperty({ type: String, nullable: true }) realExchange: string | null;
-  @ApiProperty({ type: Boolean, nullable: true }) apiTradeAvailable:
+  declare slug: string;
+  @ApiProperty() declare name: string;
+  @ApiProperty({ type: String, nullable: true }) declare isin: string | null;
+  @ApiProperty({ type: String, nullable: true }) declare classCode:
+    string | null;
+  @ApiProperty({ type: String, nullable: true }) declare realExchange:
+    string | null;
+  @ApiProperty({ type: Boolean, nullable: true }) declare apiTradeAvailable:
     boolean | null;
-  @ApiProperty({ type: String, nullable: true }) ticker: string | null;
-  @ApiProperty({ type: String, nullable: true }) logoName: string | null;
-  @ApiProperty({ type: String, nullable: true }) currency: string | null;
-  @ApiProperty({ type: String, nullable: true }) shareType: string | null;
-  @ApiProperty({ type: String, nullable: true }) sector: string | null;
-  @ApiProperty({ type: Number, nullable: true }) lot: number | null;
+  @ApiProperty({ type: String, nullable: true }) declare ticker: string | null;
+  @ApiProperty({ type: String, nullable: true }) declare logoName:
+    string | null;
+  @ApiProperty({ type: String, nullable: true }) declare currency:
+    string | null;
+  @ApiProperty({ type: String, nullable: true }) declare shareType:
+    string | null;
+  @ApiProperty({ type: String, nullable: true }) declare sector: string | null;
+  @ApiProperty({ type: Number, nullable: true }) declare lot: number | null;
   @ApiProperty({ type: String, nullable: true, format: 'date-time' })
-  historyFrom: string | null;
+  declare historyFrom: string | null;
 }
 export class StockSearchResultDto extends StockDto {
-  @ApiProperty({ type: MoneyDto, nullable: true }) price: MoneyDto | null;
-  @ApiProperty({ type: String, nullable: true, format: 'date-time' }) priceAt:
-    string | null;
+  @ApiProperty({ type: MoneyDto, nullable: true })
+  declare price: MoneyDto | null;
+  @ApiProperty({ type: String, nullable: true, format: 'date-time' })
+  declare priceAt: string | null;
 }
 export class StockQuoteDto {
-  @ApiProperty({ type: MoneyDto, nullable: true }) price: MoneyDto | null;
-  @ApiProperty({ type: String, nullable: true, format: 'date-time' }) priceAt:
-    string | null;
-  @ApiProperty({ type: String, nullable: true }) tradingStatus: string | null;
-  @ApiProperty({ type: MoneyDto, nullable: true }) change: MoneyDto | null;
-  @ApiProperty({ type: String, nullable: true }) changePercent: string | null;
-  @ApiProperty({ type: String, nullable: true, format: 'date' })
-  previousCloseDate: string | null;
   @ApiProperty({ type: MoneyDto, nullable: true })
-  previousClose: MoneyDto | null;
-  @ApiProperty({ type: [String] }) unavailable: string[];
-  @ApiProperty({ format: 'date-time' }) observedAt: string;
+  declare price: MoneyDto | null;
+  @ApiProperty({ type: String, nullable: true, format: 'date-time' })
+  declare priceAt: string | null;
+  @ApiProperty({ type: String, nullable: true }) declare tradingStatus:
+    string | null;
+  @ApiProperty({ type: MoneyDto, nullable: true })
+  declare change: MoneyDto | null;
+  @ApiProperty({ type: String, nullable: true }) declare changePercent:
+    string | null;
+  @ApiProperty({ type: String, nullable: true, format: 'date' })
+  declare previousCloseDate: string | null;
+  @ApiProperty({ type: MoneyDto, nullable: true })
+  declare previousClose: MoneyDto | null;
+  @ApiProperty({ type: [String] }) declare unavailable: string[];
+  @ApiProperty({ format: 'date-time' }) declare observedAt: string;
 }
 export class StockCandleDto {
-  @ApiProperty({ format: 'date-time' }) time: string;
-  @ApiProperty() close: string;
-  @ApiProperty() isComplete: boolean;
+  @ApiProperty({ format: 'date-time' }) declare time: string;
+  @ApiProperty() declare close: string;
+  @ApiProperty() declare isComplete: boolean;
 }
 export class StockCandlesDto {
-  @ApiProperty({ type: [StockCandleDto] }) candles: StockCandleDto[];
-  @ApiProperty({ type: String, nullable: true }) currency: string | null;
+  @ApiProperty({ type: [StockCandleDto] }) declare candles: StockCandleDto[];
+  @ApiProperty({ type: String, nullable: true }) declare currency:
+    string | null;
   @ApiProperty({ type: String, nullable: true, format: 'date-time' })
-  historyFrom: string | null;
-  @ApiProperty({ format: 'date-time' }) observedAt: string;
+  declare historyFrom: string | null;
+  @ApiProperty({ format: 'date-time' }) declare observedAt: string;
 }
 export class StockPositionRowDto extends PortfolioPositionDto {
-  @ApiProperty({ type: String, nullable: true }) returnPercent: string | null;
+  @ApiProperty({ type: String, nullable: true }) declare returnPercent:
+    string | null;
 }
 export class StockPositionDto {
-  @ApiProperty() quantity: string;
+  @ApiProperty() declare quantity: string;
   @ApiProperty({ type: MoneyDto, nullable: true })
-  currentValue: MoneyDto | null;
+  declare currentValue: MoneyDto | null;
   @ApiProperty({ type: MoneyDto, nullable: true })
-  averagePurchasePrice: MoneyDto | null;
+  declare averagePurchasePrice: MoneyDto | null;
   @ApiProperty({ type: MoneyDto, nullable: true })
-  absoluteReturn: MoneyDto | null;
-  @ApiProperty({ type: String, nullable: true }) returnPercent: string | null;
-  @ApiProperty({ type: [StockPositionRowDto] }) accounts: StockPositionRowDto[];
-  @ApiProperty() isStale: boolean;
-  @ApiProperty({ format: 'date-time' }) observedAt: string;
+  declare absoluteReturn: MoneyDto | null;
+  @ApiProperty({ type: String, nullable: true }) declare returnPercent:
+    string | null;
+  @ApiProperty({ type: [StockPositionRowDto] })
+  declare accounts: StockPositionRowDto[];
+  @ApiProperty() declare isStale: boolean;
+  @ApiProperty({ format: 'date-time' }) declare observedAt: string;
 }
 export class StockMetricDto {
-  @ApiProperty() key: string;
-  @ApiProperty() value: number;
-  @ApiProperty({ enum: ['money', 'ratio', 'percent'] }) unit:
+  @ApiProperty() declare key: string;
+  @ApiProperty() declare value: number;
+  @ApiProperty({ enum: ['money', 'ratio', 'percent'] }) declare unit:
     'money' | 'ratio' | 'percent';
-  @ApiProperty({ type: String, nullable: true }) currency: string | null;
-  @ApiProperty({ type: String, nullable: true, enum: ['TTM', 'MRQ'] }) period:
-    'TTM' | 'MRQ' | null;
+  @ApiProperty({ type: String, nullable: true }) declare currency:
+    string | null;
+  @ApiProperty({ type: String, nullable: true, enum: ['TTM', 'MRQ'] })
+  declare period: 'TTM' | 'MRQ' | null;
 }
 export class StockCompanyDto {
-  @ApiProperty({ type: String, nullable: true }) description: string | null;
-  @ApiProperty({ type: [StockMetricDto] }) metrics: StockMetricDto[];
-  @ApiProperty({ type: [String] }) unavailable: string[];
-  @ApiProperty({ format: 'date-time' }) observedAt: string;
+  @ApiProperty({ type: String, nullable: true }) declare description:
+    string | null;
+  @ApiProperty({ type: [StockMetricDto] }) declare metrics: StockMetricDto[];
+  @ApiProperty({ type: [String] }) declare unavailable: string[];
+  @ApiProperty({ format: 'date-time' }) declare observedAt: string;
 }
 export class StockDividendDto {
-  @ApiProperty({ type: MoneyDto, nullable: true }) perShare: MoneyDto | null;
-  @ApiProperty({ type: String, nullable: true, format: 'date' }) recordDate:
-    string | null;
-  @ApiProperty({ type: String, nullable: true, format: 'date' }) lastBuyDate:
-    string | null;
-  @ApiProperty({ type: String, nullable: true, format: 'date' }) paymentDate:
-    string | null;
-  @ApiProperty({ enum: ['upcoming', 'past', 'undated'] }) timing:
+  @ApiProperty({ type: MoneyDto, nullable: true })
+  declare perShare: MoneyDto | null;
+  @ApiProperty({ type: String, nullable: true, format: 'date' })
+  declare recordDate: string | null;
+  @ApiProperty({ type: String, nullable: true, format: 'date' })
+  declare lastBuyDate: string | null;
+  @ApiProperty({ type: String, nullable: true, format: 'date' })
+  declare paymentDate: string | null;
+  @ApiProperty({ enum: ['upcoming', 'past', 'undated'] }) declare timing:
     'upcoming' | 'past' | 'undated';
   @ApiProperty({ type: MoneyDto, nullable: true })
-  estimatedAmount: MoneyDto | null;
+  declare estimatedAmount: MoneyDto | null;
 }
 export class StockDividendsDto {
-  @ApiProperty({ type: [StockDividendDto] }) dividends: StockDividendDto[];
-  @ApiProperty({ format: 'date' }) from: string;
-  @ApiProperty({ format: 'date' }) to: string;
-  @ApiProperty({ format: 'date-time' }) observedAt: string;
+  @ApiProperty({ type: [StockDividendDto] })
+  declare dividends: StockDividendDto[];
+  @ApiProperty({ format: 'date' }) declare from: string;
+  @ApiProperty({ format: 'date' }) declare to: string;
+  @ApiProperty({ format: 'date-time' }) declare observedAt: string;
   @ApiProperty({ type: String, nullable: true, format: 'date-time' })
-  positionAt: string | null;
-  @ApiProperty() estimateUnavailable: boolean;
-  @ApiProperty() positionIsStale: boolean;
+  declare positionAt: string | null;
+  @ApiProperty() declare estimateUnavailable: boolean;
+  @ApiProperty() declare positionIsStale: boolean;
 }
diff --git a/src/tbank/stock.service.spec.ts b/src/tbank/stock.service.spec.ts
index 543bb8a..cb5a685 100644
--- a/src/tbank/stock.service.spec.ts
+++ b/src/tbank/stock.service.spec.ts
@@ -97,6 +97,8 @@ describe('stock market use case', () => {
     tbank.findShares.mockResolvedValue([
       ...listings,
       { uid: 'bond', instrumentKind: 'INSTRUMENT_TYPE_BOND' },
+      { instrumentKind: 'INSTRUMENT_TYPE_SHARE' },
+      { uid: '', instrumentKind: 'INSTRUMENT_TYPE_SHARE' },
     ]);
     tbank.getShare.mockImplementation((_token: string, uid: string) =>
       Promise.resolve({
diff --git a/src/tbank/stock.service.ts b/src/tbank/stock.service.ts
index 015946d..135b1b2 100644
--- a/src/tbank/stock.service.ts
+++ b/src/tbank/stock.service.ts
@@ -39,6 +39,7 @@ import {
 } from './stock.dto';
 
 const dayMs = 86_400_000;
+type IdentifiedShare = TbankShare & { uid: string };
 
 @Injectable()
 export class StockService {
@@ -64,7 +65,7 @@ export class StockService {
             async (share) =>
               (await optional(
                 () =>
-                  this.get(userId, share.uid!).catch((error: unknown) => {
+                  this.get(userId, share.uid).catch((error: unknown) => {
                     if (error instanceof NotFoundException) return stock(share);
                     throw error;
                   }),
@@ -77,7 +78,7 @@ export class StockService {
           () =>
             this.tbank.getLastPrices(
               token,
-              shares.map((share) => share.uid!),
+              shares.map((share) => share.uid),
             ),
           'prices',
           [],
@@ -131,11 +132,14 @@ export class StockService {
   async getByTicker(userId: string, ticker: string): Promise<StockDto> {
     const match = await this.tickerMatch(userId, ticker);
     return {
-      ...(await this.get(userId, match.uid!)),
+      ...(await this.get(userId, match.uid)),
       slug: ticker.trim().toUpperCase(),
     };
   }
-  private tickerMatch(userId: string, ticker: string): Promise<TbankShare> {
+  private tickerMatch(
+    userId: string,
+    ticker: string,
+  ): Promise<IdentifiedShare> {
     const normalized = ticker.trim().toUpperCase();
     return this.cached(userId, `ticker:${normalized}`, async (token) => {
       const found = await this.tbank.findShares(token, normalized);
@@ -295,7 +299,8 @@ export class StockService {
     return this.cached(userId, `company:${uid}`, async (token) => {
       const share = await this.share(token, uid);
       const unavailable: string[] = [];
-      if (!share.assetUid)
+      const assetUid = share.assetUid;
+      if (!assetUid)
         return {
           description: null,
           metrics: [],
@@ -304,12 +309,12 @@ export class StockService {
         };
       const [description, fundamentals] = await Promise.all([
         optional(
-          () => this.tbank.getAssetDescription(token, share.assetUid!),
+          () => this.tbank.getAssetDescription(token, assetUid),
           'description',
           unavailable,
         ),
         optional(
-          () => this.tbank.getFundamentals(token, share.assetUid!),
+          () => this.tbank.getFundamentals(token, assetUid),
           'fundamentals',
           unavailable,
         ),
@@ -353,12 +358,12 @@ export class StockService {
               ? { currency, value: formatDecimal(decimal(event.dividendNet)) }
               : null;
           // A future payment can have an already-fixed register: keep the event, but do not estimate entitlement from today's holding.
-          const timing: StockDividendDto['timing'] =
-            (paymentDate ?? recordDate)
-              ? (paymentDate ?? recordDate)! >= today
-                ? 'upcoming'
-                : 'past'
-              : 'undated';
+          const eventDate = paymentDate ?? recordDate;
+          const timing: StockDividendDto['timing'] = eventDate
+            ? eventDate >= today
+              ? 'upcoming'
+              : 'past'
+            : 'undated';
           const estimatedAmount =
             quantity &&
             perShare &&
@@ -393,10 +398,10 @@ export class StockService {
       };
     });
   }
-  private async share(token: string, uid: string): Promise<TbankShare> {
+  private async share(token: string, uid: string): Promise<IdentifiedShare> {
     const share = await this.tbank.getShare(token, uid);
     if (!share || share.uid !== uid) throw new NotFoundException();
-    return share;
+    return { ...share, uid };
   }
   private cached<T extends object>(
     userId: string,
@@ -417,11 +422,12 @@ export class StockService {
   }
 }
 
-function selectShares(found: TbankShare[], query: string): TbankShare[] {
+function selectShares(found: TbankShare[], query: string): IdentifiedShare[] {
   const seen = new Set<string>();
   return found
     .filter(
-      (share) => share.uid && share.instrumentKind === 'INSTRUMENT_TYPE_SHARE',
+      (share): share is IdentifiedShare =>
+        Boolean(share.uid) && share.instrumentKind === 'INSTRUMENT_TYPE_SHARE',
     )
     .sort(
       (a, b) =>
@@ -430,24 +436,24 @@ function selectShares(found: TbankShare[], query: string): TbankShare[] {
         Number(b.ticker?.toUpperCase() === query.toUpperCase()) -
           Number(a.ticker?.toUpperCase() === query.toUpperCase()) ||
         Number(b.classCode === 'TQBR') - Number(a.classCode === 'TQBR') ||
-        a.uid!.localeCompare(b.uid!),
+        a.uid.localeCompare(b.uid),
     )
     .filter((share) => {
       // A missing ISIN must not collapse unrelated catalog instruments.
       const key = share.isin?.trim()
         ? `isin:${share.isin.trim().toUpperCase()}`
-        : `uid:${share.uid!}`;
+        : `uid:${share.uid}`;
       if (seen.has(key)) return false;
       seen.add(key);
       return true;
     });
 }
 
-function stock(share: TbankShare): StockDto {
+function stock(share: IdentifiedShare): StockDto {
   return {
-    instrumentUid: share.uid!,
-    slug: share.uid!,
-    name: share.name?.trim() || share.ticker || share.uid!,
+    instrumentUid: share.uid,
+    slug: share.uid,
+    name: share.name?.trim() || share.ticker || share.uid,
     ticker: share.ticker?.trim() || null,
     isin: share.isin?.trim() || null,
     classCode: share.classCode?.trim() || null,
diff --git a/src/tbank/tbank-connection.dto.ts b/src/tbank/tbank-connection.dto.ts
index 0b8d599..32a8aae 100644
--- a/src/tbank/tbank-connection.dto.ts
+++ b/src/tbank/tbank-connection.dto.ts
@@ -6,13 +6,13 @@ export class PutTbankConnectionDto {
   @IsString()
   @IsNotEmpty()
   @MaxLength(4096)
-  token: string;
+  declare token: string;
 }
 
 export class TbankConnectionStatusDto {
   @ApiProperty()
-  connected: boolean;
+  declare connected: boolean;
 
   @ApiProperty({ type: String, nullable: true, format: 'date-time' })
-  connectedAt: string | null;
+  declare connectedAt: string | null;
 }
diff --git a/src/tbank/tbank.client.ts b/src/tbank/tbank.client.ts
index 7b3e18b..573bde8 100644
--- a/src/tbank/tbank.client.ts
+++ b/src/tbank/tbank.client.ts
@@ -233,11 +233,12 @@ export class TbankClient {
   }
 
   getOpenAccounts(token: string): Promise<TbankAccount[]> {
-    return this.call(token, this.users, 'getAccounts', {
-      status: 'ACCOUNT_STATUS_OPEN',
-    }).then(
-      (response: { accounts?: TbankAccount[] }) => response.accounts ?? [],
-    );
+    return this.call<{ accounts?: TbankAccount[] }>(
+      token,
+      this.users,
+      'getAccounts',
+      { status: 'ACCOUNT_STATUS_OPEN' },
+    ).then((response) => response.accounts ?? []);
   }
 
   getPortfolio(token: string, accountId: string): Promise<TbankPortfolio> {
@@ -275,13 +276,16 @@ export class TbankClient {
     from: string,
     to: string,
   ): Promise<TbankDividend[]> {
-    return this.call(token, this.instruments, 'getDividends', {
-      instrumentId,
-      from: { seconds: String(utcSeconds(from)) },
-      to: { seconds: String(utcSeconds(to)) },
-    }).then(
-      (response: { dividends?: TbankDividend[] }) => response.dividends ?? [],
-    );
+    return this.call<{ dividends?: TbankDividend[] }>(
+      token,
+      this.instruments,
+      'getDividends',
+      {
+        instrumentId,
+        from: { seconds: String(utcSeconds(from)) },
+        to: { seconds: String(utcSeconds(to)) },
+      },
+    ).then((response) => response.dividends ?? []);
   }
 
   findShares(token: string, query: string): Promise<TbankShare[]> {
diff --git a/src/tbank/upcoming-events.dto.ts b/src/tbank/upcoming-events.dto.ts
index c0cb27d..67875c4 100644
--- a/src/tbank/upcoming-events.dto.ts
+++ b/src/tbank/upcoming-events.dto.ts
@@ -29,46 +29,46 @@ export class UpcomingEventDto {
   account?: AccountReferenceDto;
 
   @ApiProperty({ enum: ['coupon', 'dividend', 'maturity', 'offer'] })
-  type: 'coupon' | 'dividend' | 'maturity' | 'offer';
+  declare type: 'coupon' | 'dividend' | 'maturity' | 'offer';
 
   @ApiProperty({ format: 'date' })
-  date: string;
+  declare date: string;
 
   @ApiProperty({ enum: ['event', 'registry'] })
-  dateKind: 'event' | 'registry';
+  declare dateKind: 'event' | 'registry';
 
   @ApiProperty({ type: String, nullable: true })
-  figi: string | null;
+  declare figi: string | null;
 
   @ApiProperty({ type: String, nullable: true })
-  instrumentUid: string | null;
+  declare instrumentUid: string | null;
 
   @ApiProperty()
-  ticker: string;
+  declare ticker: string;
 
   @ApiProperty()
-  displayName: string;
+  declare displayName: string;
 
   @ApiProperty({ type: String, nullable: true })
-  isin: string | null;
+  declare isin: string | null;
 
   @ApiProperty({ type: String, nullable: true })
-  logoName: string | null;
+  declare logoName: string | null;
 
   @ApiProperty({ type: MoneyDto, nullable: true })
-  projectedAmount: MoneyDto | null;
+  declare projectedAmount: MoneyDto | null;
 }
 
 export class UpcomingEventsDto {
   @ApiProperty()
-  accountId: string;
+  declare accountId: string;
 
   @ApiProperty({ format: 'date-time' })
-  calculatedAt: string;
+  declare calculatedAt: string;
 
   @ApiProperty({ type: UpcomingEventDto, isArray: true })
-  events: UpcomingEventDto[];
+  declare events: UpcomingEventDto[];
 
   @ApiProperty({ type: MoneyDto, isArray: true })
-  incomeTotalsByCurrency: MoneyDto[];
+  declare incomeTotalsByCurrency: MoneyDto[];
 }
diff --git a/src/tbank/upcoming-events.service.ts b/src/tbank/upcoming-events.service.ts
index 84021b1..9fa24a8 100644
--- a/src/tbank/upcoming-events.service.ts
+++ b/src/tbank/upcoming-events.service.ts
@@ -71,7 +71,9 @@ export class UpcomingEventsService {
     return this.access.withSupportedAccounts(
       userId,
       async ({ token, accounts }) => {
-        const events: UpcomingEventDto[] = [];
+        const events: (UpcomingEventDto & {
+          account: { id: string; name: string };
+        })[] = [];
         for (const account of accounts) {
           const result = await this.forAccount(token, account.id, window);
           events.push(
@@ -84,7 +86,7 @@ export class UpcomingEventsService {
         events.sort(
           (left, right) =>
             left.date.localeCompare(right.date) ||
-            left.account!.id.localeCompare(right.account!.id),
+            left.account.id.localeCompare(right.account.id),
         );
         return {
           accountId: 'all',
diff --git a/test/bank-cards.e2e-spec.ts b/test/bank-cards.e2e-spec.ts
index 259f90e..9ff99d4 100644
--- a/test/bank-cards.e2e-spec.ts
+++ b/test/bank-cards.e2e-spec.ts
@@ -1,3 +1,4 @@
+import assert from 'node:assert/strict';
 import { INestApplication } from '@nestjs/common';
 import { JwtService } from '@nestjs/jwt';
 import { Test } from '@nestjs/testing';
@@ -333,7 +334,8 @@ describe('Manual bank cards configured HTTP and real SQLite', () => {
     expect((await getCard(own.id)).balance.value).toBe('1000');
   });
   it('renames default category without role loss; duplicates and stale rename conflict', async () => {
-    const category = (await categories()).find((c) => c.isDefault)!;
+    const category = (await categories()).find((c) => c.isDefault);
+    assert.ok(category);
     await auth('patch', '/categories/' + category.id)
       .send({ version: category.version, name: 'Остальное' })
       .expect(200);
@@ -474,7 +476,8 @@ describe('Manual bank cards configured HTTP and real SQLite', () => {
       'delete',
       `/operations/${expense.id}?version=${current.version}`,
     ).expect(409);
-    const category = (await categories()).find((c) => !c.isDefault)!;
+    const category = (await categories()).find((c) => !c.isDefault);
+    assert.ok(category);
     await auth('patch', '/operations/' + expense.id)
       .send({ version: current.version, categoryId: category.id })
       .expect(200);
diff --git a/tsconfig.json b/tsconfig.json
index aba29b0..cccdcae 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -16,10 +16,8 @@
     "baseUrl": "./",
     "incremental": true,
     "skipLibCheck": true,
-    "strictNullChecks": true,
+    "strict": true,
     "forceConsistentCasingInFileNames": true,
-    "noImplicitAny": false,
-    "strictBindCallApply": false,
-    "noFallthroughCasesInSwitch": false
+    "noFallthroughCasesInSwitch": true
   }
 }