feat(locale): persist household and member preferences

packages/adapters-db/src/household-config-repository.ts

@@ -1,7 +1,7 @@
 import { and, eq } from 'drizzle-orm'
 
 import { createDbClient, schema } from '@household/db'
-import { instantToDate, nowInstant } from '@household/domain'
+import { instantToDate, normalizeSupportedLocale, nowInstant } from '@household/domain'
 import {
   HOUSEHOLD_TOPIC_ROLES,
   type HouseholdConfigurationRepository,
@@ -30,13 +30,20 @@ function toHouseholdTelegramChatRecord(row: {
   telegramChatId: string
   telegramChatType: string
   title: string | null
+  defaultLocale: string
 }): HouseholdTelegramChatRecord {
+  const defaultLocale = normalizeSupportedLocale(row.defaultLocale)
+  if (!defaultLocale) {
+    throw new Error(`Unsupported household default locale: ${row.defaultLocale}`)
+  }
+
   return {
     householdId: row.householdId,
     householdName: row.householdName,
     telegramChatId: row.telegramChatId,
     telegramChatType: row.telegramChatType,
-    title: row.title
+    title: row.title,
+    defaultLocale
   }
 }
 
@@ -75,14 +82,21 @@ function toHouseholdPendingMemberRecord(row: {
   displayName: string
   username: string | null
   languageCode: string | null
+  defaultLocale: string
 }): HouseholdPendingMemberRecord {
+  const householdDefaultLocale = normalizeSupportedLocale(row.defaultLocale)
+  if (!householdDefaultLocale) {
+    throw new Error(`Unsupported household default locale: ${row.defaultLocale}`)
+  }
+
   return {
     householdId: row.householdId,
     householdName: row.householdName,
     telegramUserId: row.telegramUserId,
     displayName: row.displayName,
     username: row.username,
-    languageCode: row.languageCode
+    languageCode: row.languageCode,
+    householdDefaultLocale
   }
 }
 
@@ -91,13 +105,22 @@ function toHouseholdMemberRecord(row: {
   householdId: string
   telegramUserId: string
   displayName: string
+  preferredLocale: string | null
+  defaultLocale: string
   isAdmin: number
 }): HouseholdMemberRecord {
+  const householdDefaultLocale = normalizeSupportedLocale(row.defaultLocale)
+  if (!householdDefaultLocale) {
+    throw new Error(`Unsupported household default locale: ${row.defaultLocale}`)
+  }
+
   return {
     id: row.id,
     householdId: row.householdId,
     telegramUserId: row.telegramUserId,
     displayName: row.displayName,
+    preferredLocale: normalizeSupportedLocale(row.preferredLocale),
+    householdDefaultLocale,
     isAdmin: row.isAdmin === 1
   }
 }
@@ -120,7 +143,8 @@ export function createDbHouseholdConfigurationRepository(databaseUrl: string): {
             householdName: schema.households.name,
             telegramChatId: schema.householdTelegramChats.telegramChatId,
             telegramChatType: schema.householdTelegramChats.telegramChatType,
-            title: schema.householdTelegramChats.title
+            title: schema.householdTelegramChats.title,
+            defaultLocale: schema.households.defaultLocale
           })
           .from(schema.householdTelegramChats)
           .innerJoin(
@@ -160,7 +184,8 @@ export function createDbHouseholdConfigurationRepository(databaseUrl: string): {
           })
           .returning({
             id: schema.households.id,
-            name: schema.households.name
+            name: schema.households.name,
+            defaultLocale: schema.households.defaultLocale
           })
 
         const household = insertedHouseholds[0]
@@ -195,7 +220,8 @@ export function createDbHouseholdConfigurationRepository(databaseUrl: string): {
             householdName: household.name,
             telegramChatId: chat.telegramChatId,
             telegramChatType: chat.telegramChatType,
-            title: chat.title
+            title: chat.title,
+            defaultLocale: household.defaultLocale
           })
         }
       })
@@ -208,7 +234,8 @@ export function createDbHouseholdConfigurationRepository(databaseUrl: string): {
           householdName: schema.households.name,
           telegramChatId: schema.householdTelegramChats.telegramChatId,
           telegramChatType: schema.householdTelegramChats.telegramChatType,
-          title: schema.householdTelegramChats.title
+          title: schema.householdTelegramChats.title,
+          defaultLocale: schema.households.defaultLocale
         })
         .from(schema.householdTelegramChats)
         .innerJoin(
@@ -229,7 +256,8 @@ export function createDbHouseholdConfigurationRepository(databaseUrl: string): {
           householdName: schema.households.name,
           telegramChatId: schema.householdTelegramChats.telegramChatId,
           telegramChatType: schema.householdTelegramChats.telegramChatType,
-          title: schema.householdTelegramChats.title
+          title: schema.householdTelegramChats.title,
+          defaultLocale: schema.households.defaultLocale
         })
         .from(schema.householdTelegramChats)
         .innerJoin(
@@ -412,7 +440,8 @@ export function createDbHouseholdConfigurationRepository(databaseUrl: string): {
           householdName: schema.households.name,
           telegramChatId: schema.householdTelegramChats.telegramChatId,
           telegramChatType: schema.householdTelegramChats.telegramChatType,
-          title: schema.householdTelegramChats.title
+          title: schema.householdTelegramChats.title,
+          defaultLocale: schema.households.defaultLocale
         })
         .from(schema.householdJoinTokens)
         .innerJoin(
@@ -468,7 +497,8 @@ export function createDbHouseholdConfigurationRepository(databaseUrl: string): {
       const householdRows = await db
         .select({
           householdId: schema.households.id,
-          householdName: schema.households.name
+          householdName: schema.households.name,
+          defaultLocale: schema.households.defaultLocale
         })
         .from(schema.households)
         .where(eq(schema.households.id, row.householdId))
@@ -485,7 +515,8 @@ export function createDbHouseholdConfigurationRepository(databaseUrl: string): {
         telegramUserId: row.telegramUserId,
         displayName: row.displayName,
         username: row.username,
-        languageCode: row.languageCode
+        languageCode: row.languageCode,
+        defaultLocale: household.defaultLocale
       })
     },
 
@@ -497,7 +528,8 @@ export function createDbHouseholdConfigurationRepository(databaseUrl: string): {
           telegramUserId: schema.householdPendingMembers.telegramUserId,
           displayName: schema.householdPendingMembers.displayName,
           username: schema.householdPendingMembers.username,
-          languageCode: schema.householdPendingMembers.languageCode
+          languageCode: schema.householdPendingMembers.languageCode,
+          defaultLocale: schema.households.defaultLocale
         })
         .from(schema.householdPendingMembers)
         .innerJoin(
@@ -524,7 +556,8 @@ export function createDbHouseholdConfigurationRepository(databaseUrl: string): {
           telegramUserId: schema.householdPendingMembers.telegramUserId,
           displayName: schema.householdPendingMembers.displayName,
           username: schema.householdPendingMembers.username,
-          languageCode: schema.householdPendingMembers.languageCode
+          languageCode: schema.householdPendingMembers.languageCode,
+          defaultLocale: schema.households.defaultLocale
         })
         .from(schema.householdPendingMembers)
         .innerJoin(
@@ -545,12 +578,14 @@ export function createDbHouseholdConfigurationRepository(databaseUrl: string): {
           householdId: input.householdId,
           telegramUserId: input.telegramUserId,
           displayName: input.displayName,
+          preferredLocale: input.preferredLocale ?? null,
           isAdmin: input.isAdmin ? 1 : 0
         })
         .onConflictDoUpdate({
           target: [schema.members.householdId, schema.members.telegramUserId],
           set: {
             displayName: input.displayName,
+            preferredLocale: input.preferredLocale ?? schema.members.preferredLocale,
             ...(input.isAdmin
               ? {
                   isAdmin: 1
@@ -563,6 +598,7 @@ export function createDbHouseholdConfigurationRepository(databaseUrl: string): {
           householdId: schema.members.householdId,
           telegramUserId: schema.members.telegramUserId,
           displayName: schema.members.displayName,
+          preferredLocale: schema.members.preferredLocale,
           isAdmin: schema.members.isAdmin
         })
 
@@ -571,7 +607,15 @@ export function createDbHouseholdConfigurationRepository(databaseUrl: string): {
         throw new Error('Failed to ensure household member')
       }
 
-      return toHouseholdMemberRecord(row)
+      const household = await this.getHouseholdChatByHouseholdId(row.householdId)
+      if (!household) {
+        throw new Error('Failed to resolve household for member')
+      }
+
+      return toHouseholdMemberRecord({
+        ...row,
+        defaultLocale: household.defaultLocale
+      })
     },
 
     async getHouseholdMember(householdId, telegramUserId) {
@@ -581,9 +625,12 @@ export function createDbHouseholdConfigurationRepository(databaseUrl: string): {
           householdId: schema.members.householdId,
           telegramUserId: schema.members.telegramUserId,
           displayName: schema.members.displayName,
+          preferredLocale: schema.members.preferredLocale,
+          defaultLocale: schema.households.defaultLocale,
           isAdmin: schema.members.isAdmin
         })
         .from(schema.members)
+        .innerJoin(schema.households, eq(schema.members.householdId, schema.households.id))
         .where(
           and(
             eq(schema.members.householdId, householdId),
@@ -603,9 +650,12 @@ export function createDbHouseholdConfigurationRepository(databaseUrl: string): {
           householdId: schema.members.householdId,
           telegramUserId: schema.members.telegramUserId,
           displayName: schema.members.displayName,
+          preferredLocale: schema.members.preferredLocale,
+          defaultLocale: schema.households.defaultLocale,
           isAdmin: schema.members.isAdmin
         })
         .from(schema.members)
+        .innerJoin(schema.households, eq(schema.members.householdId, schema.households.id))
         .where(eq(schema.members.householdId, householdId))
         .orderBy(schema.members.displayName, schema.members.telegramUserId)
 
@@ -619,9 +669,12 @@ export function createDbHouseholdConfigurationRepository(databaseUrl: string): {
           householdId: schema.members.householdId,
           telegramUserId: schema.members.telegramUserId,
           displayName: schema.members.displayName,
+          preferredLocale: schema.members.preferredLocale,
+          defaultLocale: schema.households.defaultLocale,
           isAdmin: schema.members.isAdmin
         })
         .from(schema.members)
+        .innerJoin(schema.households, eq(schema.members.householdId, schema.households.id))
         .where(eq(schema.members.telegramUserId, telegramUserId))
         .orderBy(schema.members.householdId, schema.members.displayName)
 
@@ -636,7 +689,8 @@ export function createDbHouseholdConfigurationRepository(databaseUrl: string): {
           telegramUserId: schema.householdPendingMembers.telegramUserId,
           displayName: schema.householdPendingMembers.displayName,
           username: schema.householdPendingMembers.username,
-          languageCode: schema.householdPendingMembers.languageCode
+          languageCode: schema.householdPendingMembers.languageCode,
+          defaultLocale: schema.households.defaultLocale
         })
         .from(schema.householdPendingMembers)
         .innerJoin(
@@ -658,7 +712,8 @@ export function createDbHouseholdConfigurationRepository(databaseUrl: string): {
             telegramUserId: schema.householdPendingMembers.telegramUserId,
             displayName: schema.householdPendingMembers.displayName,
             username: schema.householdPendingMembers.username,
-            languageCode: schema.householdPendingMembers.languageCode
+            languageCode: schema.householdPendingMembers.languageCode,
+            defaultLocale: schema.households.defaultLocale
           })
           .from(schema.householdPendingMembers)
           .innerJoin(
@@ -684,12 +739,15 @@ export function createDbHouseholdConfigurationRepository(databaseUrl: string): {
             householdId: pending.householdId,
             telegramUserId: pending.telegramUserId,
             displayName: pending.displayName,
+            preferredLocale: normalizeSupportedLocale(pending.languageCode),
             isAdmin: input.isAdmin ? 1 : 0
           })
           .onConflictDoUpdate({
             target: [schema.members.householdId, schema.members.telegramUserId],
             set: {
               displayName: pending.displayName,
+              preferredLocale:
+                normalizeSupportedLocale(pending.languageCode) ?? schema.members.preferredLocale,
               ...(input.isAdmin
                 ? {
                     isAdmin: 1
@@ -702,6 +760,7 @@ export function createDbHouseholdConfigurationRepository(databaseUrl: string): {
             householdId: schema.members.householdId,
             telegramUserId: schema.members.telegramUserId,
             displayName: schema.members.displayName,
+            preferredLocale: schema.members.preferredLocale,
             isAdmin: schema.members.isAdmin
           })
 
@@ -719,7 +778,76 @@ export function createDbHouseholdConfigurationRepository(databaseUrl: string): {
           throw new Error('Failed to approve pending household member')
         }
 
-        return toHouseholdMemberRecord(member)
+        return toHouseholdMemberRecord({
+          ...member,
+          defaultLocale: pending.defaultLocale
+        })
+      })
+    },
+
+    async updateHouseholdDefaultLocale(householdId, locale) {
+      const updatedHouseholds = await db
+        .update(schema.households)
+        .set({
+          defaultLocale: locale
+        })
+        .where(eq(schema.households.id, householdId))
+        .returning({
+          id: schema.households.id,
+          name: schema.households.name,
+          defaultLocale: schema.households.defaultLocale
+        })
+
+      const household = updatedHouseholds[0]
+      if (!household) {
+        throw new Error('Failed to update household default locale')
+      }
+
+      const chat = await this.getHouseholdChatByHouseholdId(householdId)
+      if (!chat) {
+        throw new Error('Failed to resolve household chat after locale update')
+      }
+
+      return {
+        ...chat,
+        defaultLocale: normalizeSupportedLocale(household.defaultLocale) ?? chat.defaultLocale
+      }
+    },
+
+    async updateMemberPreferredLocale(householdId, telegramUserId, locale) {
+      const rows = await db
+        .update(schema.members)
+        .set({
+          preferredLocale: locale
+        })
+        .where(
+          and(
+            eq(schema.members.householdId, householdId),
+            eq(schema.members.telegramUserId, telegramUserId)
+          )
+        )
+        .returning({
+          id: schema.members.id,
+          householdId: schema.members.householdId,
+          telegramUserId: schema.members.telegramUserId,
+          displayName: schema.members.displayName,
+          preferredLocale: schema.members.preferredLocale,
+          isAdmin: schema.members.isAdmin
+        })
+
+      const row = rows[0]
+      if (!row) {
+        return null
+      }
+
+      const household = await this.getHouseholdChatByHouseholdId(householdId)
+      if (!household) {
+        throw new Error('Failed to resolve household chat after member locale update')
+      }
+
+      return toHouseholdMemberRecord({
+        ...row,
+        defaultLocale: household.defaultLocale
       })
     }
   }

packages/application/src/household-admin-service.test.ts

@@ -17,7 +17,8 @@ function createRepositoryStub() {
     householdName: 'Kojori House',
     telegramChatId: '-100123',
     telegramChatType: 'supergroup',
-    title: 'Kojori House'
+    title: 'Kojori House',
+    defaultLocale: 'ru'
   }
   const members = new Map<string, HouseholdMemberRecord>()
   const pendingMembers = new Map<string, HouseholdPendingMemberRecord>()
@@ -27,6 +28,8 @@ function createRepositoryStub() {
     householdId: household.householdId,
     telegramUserId: '1',
     displayName: 'Stan',
+    preferredLocale: null,
+    householdDefaultLocale: household.defaultLocale,
     isAdmin: true
   })
   pendingMembers.set('2', {
@@ -35,7 +38,8 @@ function createRepositoryStub() {
     telegramUserId: '2',
     displayName: 'Alice',
     username: 'alice',
-    languageCode: 'en'
+    languageCode: 'en',
+    householdDefaultLocale: household.defaultLocale
   })
 
   const repository: HouseholdConfigurationRepository = {
@@ -71,7 +75,8 @@ function createRepositoryStub() {
         telegramUserId: input.telegramUserId,
         displayName: input.displayName,
         username: input.username?.trim() || null,
-        languageCode: input.languageCode?.trim() || null
+        languageCode: input.languageCode?.trim() || null,
+        householdDefaultLocale: household.defaultLocale
       }
       pendingMembers.set(input.telegramUserId, record)
       return record
@@ -86,6 +91,8 @@ function createRepositoryStub() {
         householdId: input.householdId,
         telegramUserId: input.telegramUserId,
         displayName: input.displayName,
+        preferredLocale: input.preferredLocale ?? null,
+        householdDefaultLocale: household.defaultLocale,
         isAdmin: input.isAdmin === true
       }
       members.set(input.telegramUserId, record)
@@ -110,10 +117,25 @@ function createRepositoryStub() {
         householdId: pending.householdId,
         telegramUserId: pending.telegramUserId,
         displayName: pending.displayName,
+        preferredLocale: null,
+        householdDefaultLocale: household.defaultLocale,
         isAdmin: input.isAdmin === true
       }
       members.set(member.telegramUserId, member)
       return member
+    },
+    updateHouseholdDefaultLocale: async (_householdId, locale) => ({
+      ...household,
+      defaultLocale: locale
+    }),
+    updateMemberPreferredLocale: async (_householdId, telegramUserId, locale) => {
+      const member = members.get(telegramUserId)
+      return member
+        ? {
+            ...member,
+            preferredLocale: locale
+          }
+        : null
     }
   }
 
@@ -144,7 +166,8 @@ describe('createHouseholdAdminService', () => {
         telegramUserId: '2',
         displayName: 'Alice',
         username: 'alice',
-        languageCode: 'en'
+        languageCode: 'en',
+        householdDefaultLocale: 'ru'
       }
     ])
   })
@@ -182,6 +205,8 @@ describe('createHouseholdAdminService', () => {
         householdId: 'household-1',
         telegramUserId: '2',
         displayName: 'Alice',
+        preferredLocale: null,
+        householdDefaultLocale: 'ru',
         isAdmin: false
       }
     })

packages/application/src/household-onboarding-service.test.ts

@@ -17,7 +17,8 @@ function createRepositoryStub() {
     householdName: 'Kojori House',
     telegramChatId: '-100123',
     telegramChatType: 'supergroup',
-    title: 'Kojori House'
+    title: 'Kojori House',
+    defaultLocale: 'ru'
   }
   let joinToken: HouseholdJoinTokenRecord | null = null
   const pendingMembers = new Map<string, HouseholdPendingMemberRecord>()
@@ -76,7 +77,8 @@ function createRepositoryStub() {
         telegramUserId: input.telegramUserId,
         displayName: input.displayName,
         username: input.username?.trim() || null,
-        languageCode: input.languageCode?.trim() || null
+        languageCode: input.languageCode?.trim() || null,
+        householdDefaultLocale: household.defaultLocale
       }
       pendingMembers.set(input.telegramUserId, record)
       return record
@@ -93,6 +95,8 @@ function createRepositoryStub() {
         householdId: input.householdId,
         telegramUserId: input.telegramUserId,
         displayName: input.displayName,
+        preferredLocale: input.preferredLocale ?? null,
+        householdDefaultLocale: household.defaultLocale,
         isAdmin: input.isAdmin === true
       }
       members.set(input.telegramUserId, member)
@@ -124,8 +128,25 @@ function createRepositoryStub() {
         householdId: pending.householdId,
         telegramUserId: pending.telegramUserId,
         displayName: pending.displayName,
+        preferredLocale: null,
+        householdDefaultLocale: household.defaultLocale,
         isAdmin: input.isAdmin === true
       }
+    },
+    async updateHouseholdDefaultLocale(_householdId, locale) {
+      return {
+        ...household,
+        defaultLocale: locale
+      }
+    },
+    async updateMemberPreferredLocale(_householdId, telegramUserId, locale) {
+      const member = members.get(telegramUserId)
+      return member
+        ? {
+            ...member,
+            preferredLocale: locale
+          }
+        : null
     }
   }
 
@@ -176,7 +197,8 @@ describe('createHouseholdOnboardingService', () => {
       status: 'join_required',
       household: {
         id: 'household-1',
-        name: 'Kojori House'
+        name: 'Kojori House',
+        defaultLocale: 'ru'
       }
     })
   })
@@ -204,7 +226,8 @@ describe('createHouseholdOnboardingService', () => {
       status: 'pending',
       household: {
         id: 'household-1',
-        name: 'Kojori House'
+        name: 'Kojori House',
+        defaultLocale: 'ru'
       }
     })
 
@@ -219,7 +242,8 @@ describe('createHouseholdOnboardingService', () => {
       status: 'pending',
       household: {
         id: 'household-1',
-        name: 'Kojori House'
+        name: 'Kojori House',
+        defaultLocale: 'ru'
       }
     })
   })
@@ -250,6 +274,8 @@ describe('createHouseholdOnboardingService', () => {
         id: 'member-42',
         householdId: 'household-1',
         displayName: 'Stan',
+        preferredLocale: null,
+        householdDefaultLocale: 'ru',
         isAdmin: true
       }
     })
@@ -262,6 +288,8 @@ describe('createHouseholdOnboardingService', () => {
       householdId: 'household-1',
       telegramUserId: '42',
       displayName: 'Stan',
+      preferredLocale: null,
+      householdDefaultLocale: 'ru',
       isAdmin: true
     }
     const service = createHouseholdOnboardingService({ repository })
@@ -277,6 +305,8 @@ describe('createHouseholdOnboardingService', () => {
         householdId: 'household-2',
         telegramUserId: '42',
         displayName: 'Stan elsewhere',
+        preferredLocale: null,
+        householdDefaultLocale: 'ru',
         isAdmin: false
       }
     ]

packages/application/src/household-onboarding-service.ts

@@ -1,5 +1,6 @@
 import { randomBytes } from 'node:crypto'
 
+import type { SupportedLocale } from '@household/domain'
 import type { HouseholdConfigurationRepository, HouseholdMemberRecord } from '@household/ports'
 
 export interface HouseholdOnboardingIdentity {
@@ -17,6 +18,8 @@ export type HouseholdMiniAppAccess =
         householdId: string
         displayName: string
         isAdmin: boolean
+        preferredLocale: SupportedLocale | null
+        householdDefaultLocale: SupportedLocale
       }
     }
   | {
@@ -24,6 +27,7 @@ export type HouseholdMiniAppAccess =
       household: {
         id: string
         name: string
+        defaultLocale: SupportedLocale
       }
     }
   | {
@@ -31,6 +35,7 @@ export type HouseholdMiniAppAccess =
       household: {
         id: string
         name: string
+        defaultLocale: SupportedLocale
       }
     }
   | {
@@ -53,6 +58,7 @@ export interface HouseholdOnboardingService {
         household: {
           id: string
           name: string
+          defaultLocale: SupportedLocale
         }
       }
     | {
@@ -62,6 +68,8 @@ export interface HouseholdOnboardingService {
           householdId: string
           displayName: string
           isAdmin: boolean
+          preferredLocale: SupportedLocale | null
+          householdDefaultLocale: SupportedLocale
         }
       }
     | {
@@ -75,12 +83,16 @@ function toMember(member: HouseholdMemberRecord): {
   householdId: string
   displayName: string
   isAdmin: boolean
+  preferredLocale: SupportedLocale | null
+  householdDefaultLocale: SupportedLocale
 } {
   return {
     id: member.id,
     householdId: member.householdId,
     displayName: member.displayName,
-    isAdmin: member.isAdmin
+    isAdmin: member.isAdmin,
+    preferredLocale: member.preferredLocale,
+    householdDefaultLocale: member.householdDefaultLocale
   }
 }
 
@@ -155,7 +167,8 @@ export function createHouseholdOnboardingService(options: {
           status: 'pending',
           household: {
             id: existingPending.householdId,
-            name: existingPending.householdName
+            name: existingPending.householdName,
+            defaultLocale: existingPending.householdDefaultLocale
           }
         }
       }
@@ -182,7 +195,8 @@ export function createHouseholdOnboardingService(options: {
           status: 'pending',
           household: {
             id: pending.householdId,
-            name: pending.householdName
+            name: pending.householdName,
+            defaultLocale: pending.householdDefaultLocale
           }
         }
       }
@@ -191,7 +205,8 @@ export function createHouseholdOnboardingService(options: {
         status: 'join_required',
         household: {
           id: household.householdId,
-          name: household.householdName
+          name: household.householdName,
+          defaultLocale: household.defaultLocale
         }
       }
     },
@@ -235,7 +250,8 @@ export function createHouseholdOnboardingService(options: {
         status: 'pending',
         household: {
           id: pending.householdId,
-          name: pending.householdName
+          name: pending.householdName,
+          defaultLocale: pending.householdDefaultLocale
         }
       }
     }

packages/application/src/household-setup-service.test.ts

@@ -39,7 +39,8 @@ function createRepositoryStub() {
         householdName: input.householdName,
         telegramChatId: input.telegramChatId,
         telegramChatType: input.telegramChatType,
-        title: input.title?.trim() || null
+        title: input.title?.trim() || null,
+        defaultLocale: 'ru'
       }
       households.set(input.telegramChatId, created)
 
@@ -141,7 +142,8 @@ function createRepositoryStub() {
         telegramUserId: input.telegramUserId,
         displayName: input.displayName,
         username: input.username?.trim() || null,
-        languageCode: input.languageCode?.trim() || null
+        languageCode: input.languageCode?.trim() || null,
+        householdDefaultLocale: household.defaultLocale
       }
       pendingMembers.set(key, record)
       return record
@@ -166,6 +168,10 @@ function createRepositoryStub() {
         householdId: input.householdId,
         telegramUserId: input.telegramUserId,
         displayName: input.displayName,
+        preferredLocale: input.preferredLocale ?? existing?.preferredLocale ?? null,
+        householdDefaultLocale:
+          [...households.values()].find((household) => household.householdId === input.householdId)
+            ?.defaultLocale ?? 'ru',
         isAdmin: input.isAdmin === true || existing?.isAdmin === true
       }
       members.set(key, next)
@@ -202,10 +208,39 @@ function createRepositoryStub() {
         householdId: pending.householdId,
         telegramUserId: pending.telegramUserId,
         displayName: pending.displayName,
+        preferredLocale: null,
+        householdDefaultLocale:
+          [...households.values()].find(
+            (household) => household.householdId === pending.householdId
+          )?.defaultLocale ?? 'ru',
         isAdmin: input.isAdmin === true
       }
       members.set(key, member)
       return member
+    },
+    async updateHouseholdDefaultLocale(householdId, locale) {
+      const household =
+        [...households.values()].find((entry) => entry.householdId === householdId) ?? null
+      if (!household) {
+        throw new Error('Missing household')
+      }
+
+      const next = {
+        ...household,
+        defaultLocale: locale
+      }
+      households.set(next.telegramChatId, next)
+      return next
+    },
+    async updateMemberPreferredLocale(householdId, telegramUserId, locale) {
+      const key = `${householdId}:${telegramUserId}`
+      const member = members.get(key)
+      return member
+        ? {
+            ...member,
+            preferredLocale: locale
+          }
+        : null
     }
   }
 
@@ -240,6 +275,8 @@ describe('createHouseholdSetupService', () => {
       householdId: result.household.householdId,
       telegramUserId: '42',
       displayName: 'Stan',
+      preferredLocale: null,
+      householdDefaultLocale: 'ru',
       isAdmin: true
     })
   })
@@ -275,6 +312,8 @@ describe('createHouseholdSetupService', () => {
       householdId: result.household.householdId,
       telegramUserId: '77',
       displayName: 'Mia',
+      preferredLocale: null,
+      householdDefaultLocale: 'ru',
       isAdmin: true
     })
   })

packages/application/src/index.ts

@@ -19,6 +19,10 @@ export {
   type ReminderJobResult,
   type ReminderJobService
 } from './reminder-job-service'
+export {
+  createLocalePreferenceService,
+  type LocalePreferenceService
+} from './locale-preference-service'
 export {
   parsePurchaseMessage,
   type ParsedPurchaseResult,

packages/application/src/locale-preference-service.test.ts

@@ -0,0 +1,115 @@
+import { describe, expect, test } from 'bun:test'
+
+import type { HouseholdConfigurationRepository, HouseholdMemberRecord } from '@household/ports'
+
+import { createLocalePreferenceService } from './locale-preference-service'
+
+function createRepository(): HouseholdConfigurationRepository {
+  const household = {
+    householdId: 'household-1',
+    householdName: 'Kojori House',
+    telegramChatId: '-100123',
+    telegramChatType: 'supergroup',
+    title: 'Kojori House',
+    defaultLocale: 'ru' as const
+  }
+
+  const member: HouseholdMemberRecord = {
+    id: 'member-1',
+    householdId: 'household-1',
+    telegramUserId: '123456',
+    displayName: 'Stan',
+    preferredLocale: null,
+    householdDefaultLocale: 'ru',
+    isAdmin: true
+  }
+
+  return {
+    registerTelegramHouseholdChat: async () => ({ status: 'existing', household }),
+    getTelegramHouseholdChat: async () => household,
+    getHouseholdChatByHouseholdId: async () => household,
+    bindHouseholdTopic: async (input) => ({
+      householdId: input.householdId,
+      role: input.role,
+      telegramThreadId: input.telegramThreadId,
+      topicName: input.topicName?.trim() || null
+    }),
+    getHouseholdTopicBinding: async () => null,
+    findHouseholdTopicByTelegramContext: async () => null,
+    listHouseholdTopicBindings: async () => [],
+    upsertHouseholdJoinToken: async () => ({
+      householdId: household.householdId,
+      householdName: household.householdName,
+      token: 'join-token',
+      createdByTelegramUserId: null
+    }),
+    getHouseholdJoinToken: async () => null,
+    getHouseholdByJoinToken: async () => household,
+    upsertPendingHouseholdMember: async (input) => ({
+      householdId: input.householdId,
+      householdName: household.householdName,
+      telegramUserId: input.telegramUserId,
+      displayName: input.displayName,
+      username: input.username?.trim() || null,
+      languageCode: input.languageCode?.trim() || null,
+      householdDefaultLocale: 'ru'
+    }),
+    getPendingHouseholdMember: async () => null,
+    findPendingHouseholdMemberByTelegramUserId: async () => null,
+    ensureHouseholdMember: async () => member,
+    getHouseholdMember: async () => member,
+    listHouseholdMembers: async () => [member],
+    listHouseholdMembersByTelegramUserId: async () => [member],
+    listPendingHouseholdMembers: async () => [],
+    approvePendingHouseholdMember: async () => member,
+    updateHouseholdDefaultLocale: async (_householdId, locale) => ({
+      ...household,
+      defaultLocale: locale
+    }),
+    updateMemberPreferredLocale: async (_householdId, telegramUserId, locale) =>
+      telegramUserId === member.telegramUserId
+        ? {
+            ...member,
+            preferredLocale: locale,
+            householdDefaultLocale: 'ru'
+          }
+        : null
+  }
+}
+
+describe('createLocalePreferenceService', () => {
+  test('updates member locale preference', async () => {
+    const service = createLocalePreferenceService(createRepository())
+
+    const result = await service.updateMemberLocale({
+      householdId: 'household-1',
+      telegramUserId: '123456',
+      locale: 'en'
+    })
+
+    expect(result).toEqual({
+      status: 'updated',
+      member: {
+        householdId: 'household-1',
+        telegramUserId: '123456',
+        preferredLocale: 'en',
+        householdDefaultLocale: 'ru'
+      }
+    })
+  })
+
+  test('rejects household locale update for non-admin actors', async () => {
+    const service = createLocalePreferenceService(createRepository())
+
+    const result = await service.updateHouseholdLocale({
+      householdId: 'household-1',
+      actorIsAdmin: false,
+      locale: 'en'
+    })
+
+    expect(result).toEqual({
+      status: 'rejected',
+      reason: 'not_admin'
+    })
+  })
+})

packages/application/src/locale-preference-service.ts

@@ -0,0 +1,94 @@
+import type { SupportedLocale } from '@household/domain'
+import type { HouseholdConfigurationRepository } from '@household/ports'
+
+export interface LocalePreferenceService {
+  updateMemberLocale(input: {
+    householdId: string
+    telegramUserId: string
+    locale: SupportedLocale
+  }): Promise<
+    | {
+        status: 'updated'
+        member: {
+          householdId: string
+          telegramUserId: string
+          preferredLocale: SupportedLocale | null
+          householdDefaultLocale: SupportedLocale
+        }
+      }
+    | {
+        status: 'rejected'
+        reason: 'member_not_found'
+      }
+  >
+  updateHouseholdLocale(input: {
+    householdId: string
+    actorIsAdmin: boolean
+    locale: SupportedLocale
+  }): Promise<
+    | {
+        status: 'updated'
+        household: {
+          householdId: string
+          defaultLocale: SupportedLocale
+        }
+      }
+    | {
+        status: 'rejected'
+        reason: 'not_admin'
+      }
+  >
+}
+
+export function createLocalePreferenceService(
+  repository: HouseholdConfigurationRepository
+): LocalePreferenceService {
+  return {
+    async updateMemberLocale(input) {
+      const member = await repository.updateMemberPreferredLocale(
+        input.householdId,
+        input.telegramUserId,
+        input.locale
+      )
+
+      if (!member) {
+        return {
+          status: 'rejected',
+          reason: 'member_not_found' as const
+        }
+      }
+
+      return {
+        status: 'updated',
+        member: {
+          householdId: member.householdId,
+          telegramUserId: member.telegramUserId,
+          preferredLocale: member.preferredLocale,
+          householdDefaultLocale: member.householdDefaultLocale
+        }
+      }
+    },
+
+    async updateHouseholdLocale(input) {
+      if (!input.actorIsAdmin) {
+        return {
+          status: 'rejected',
+          reason: 'not_admin' as const
+        }
+      }
+
+      const household = await repository.updateHouseholdDefaultLocale(
+        input.householdId,
+        input.locale
+      )
+
+      return {
+        status: 'updated',
+        household: {
+          householdId: household.householdId,
+          defaultLocale: household.defaultLocale
+        }
+      }
+    }
+  }
+}

packages/application/src/miniapp-admin-service.test.ts

@@ -13,7 +13,8 @@ function repository(): HouseholdConfigurationRepository {
         householdName: 'Kojori House',
         telegramChatId: '-100123',
         telegramChatType: 'supergroup',
-        title: 'Kojori House'
+        title: 'Kojori House',
+        defaultLocale: 'ru'
       }
     }),
     getTelegramHouseholdChat: async () => null,
@@ -41,7 +42,8 @@ function repository(): HouseholdConfigurationRepository {
       telegramUserId: input.telegramUserId,
       displayName: input.displayName,
       username: input.username?.trim() || null,
-      languageCode: input.languageCode?.trim() || null
+      languageCode: input.languageCode?.trim() || null,
+      householdDefaultLocale: 'ru'
     }),
     getPendingHouseholdMember: async () => null,
     findPendingHouseholdMemberByTelegramUserId: async () => null,
@@ -50,6 +52,8 @@ function repository(): HouseholdConfigurationRepository {
       householdId: input.householdId,
       telegramUserId: input.telegramUserId,
       displayName: input.displayName,
+      preferredLocale: input.preferredLocale ?? null,
+      householdDefaultLocale: 'ru',
       isAdmin: input.isAdmin === true
     }),
     getHouseholdMember: async () => null,
@@ -62,7 +66,8 @@ function repository(): HouseholdConfigurationRepository {
         telegramUserId: '123456',
         displayName: 'Stan',
         username: 'stan',
-        languageCode: 'ru'
+        languageCode: 'ru',
+        householdDefaultLocale: 'ru'
       }
     ],
     approvePendingHouseholdMember: async (input) =>
@@ -72,6 +77,28 @@ function repository(): HouseholdConfigurationRepository {
             householdId: input.householdId,
             telegramUserId: input.telegramUserId,
             displayName: 'Stan',
+            preferredLocale: null,
+            householdDefaultLocale: 'ru',
+            isAdmin: false
+          }
+        : null,
+    updateHouseholdDefaultLocale: async (_householdId, locale) => ({
+      householdId: 'household-1',
+      householdName: 'Kojori House',
+      telegramChatId: '-100123',
+      telegramChatType: 'supergroup',
+      title: 'Kojori House',
+      defaultLocale: locale
+    }),
+    updateMemberPreferredLocale: async (_householdId, telegramUserId, locale) =>
+      telegramUserId === '123456'
+        ? {
+            id: 'member-123456',
+            householdId: 'household-1',
+            telegramUserId,
+            displayName: 'Stan',
+            preferredLocale: locale,
+            householdDefaultLocale: 'ru',
             isAdmin: false
           }
         : null
@@ -96,7 +123,8 @@ describe('createMiniAppAdminService', () => {
           telegramUserId: '123456',
           displayName: 'Stan',
           username: 'stan',
-          languageCode: 'ru'
+          languageCode: 'ru',
+          householdDefaultLocale: 'ru'
         }
       ]
     })
@@ -132,6 +160,8 @@ describe('createMiniAppAdminService', () => {
         householdId: 'household-1',
         telegramUserId: '123456',
         displayName: 'Stan',
+        preferredLocale: null,
+        householdDefaultLocale: 'ru',
         isAdmin: false
       }
     })

packages/db/drizzle/0008_lowly_spiral.sql

@@ -0,0 +1,2 @@
+ALTER TABLE "households" ADD COLUMN "default_locale" text DEFAULT 'ru' NOT NULL;--> statement-breakpoint
+ALTER TABLE "members" ADD COLUMN "preferred_locale" text;--> statement-breakpoint

packages/db/drizzle/meta/_journal.json

@@ -57,6 +57,13 @@
       "when": 1773051000000,
       "tag": "0007_sudden_murmur",
       "breakpoints": true
+    },
+    {
+      "idx": 8,
+      "version": "7",
+      "when": 1773047624171,
+      "tag": "0008_lowly_spiral",
+      "breakpoints": true
     }
   ]
 }

packages/db/src/schema.ts

@@ -15,6 +15,7 @@ import {
 export const households = pgTable('households', {
   id: uuid('id').defaultRandom().primaryKey(),
   name: text('name').notNull(),
+  defaultLocale: text('default_locale').default('ru').notNull(),
   createdAt: timestamp('created_at', { withTimezone: true }).defaultNow().notNull()
 })
 
@@ -142,6 +143,7 @@ export const members = pgTable(
       .references(() => households.id, { onDelete: 'cascade' }),
     telegramUserId: text('telegram_user_id').notNull(),
     displayName: text('display_name').notNull(),
+    preferredLocale: text('preferred_locale'),
     isAdmin: integer('is_admin').default(0).notNull(),
     joinedAt: timestamp('joined_at', { withTimezone: true }).defaultNow().notNull()
   },

packages/domain/src/index.ts

@@ -2,6 +2,7 @@ export { BillingPeriod } from './billing-period'
 export { DOMAIN_ERROR_CODE, DomainError } from './errors'
 export { BillingCycleId, HouseholdId, MemberId, PurchaseEntryId } from './ids'
 export { CURRENCIES, Money } from './money'
+export { normalizeSupportedLocale, SUPPORTED_LOCALES } from './locale'
 export {
   Temporal,
   instantFromDatabaseValue,
@@ -13,6 +14,7 @@ export {
   nowInstant
 } from './time'
 export type { CurrencyCode } from './money'
+export type { SupportedLocale } from './locale'
 export type { Instant } from './time'
 export type {
   SettlementInput,

packages/domain/src/locale.ts

@@ -0,0 +1,14 @@
+export const SUPPORTED_LOCALES = ['en', 'ru'] as const
+
+export type SupportedLocale = (typeof SUPPORTED_LOCALES)[number]
+
+export function normalizeSupportedLocale(value?: string | null): SupportedLocale | null {
+  const normalized = value?.trim().toLowerCase()
+  if (!normalized) {
+    return null
+  }
+
+  return (SUPPORTED_LOCALES as readonly string[]).includes(normalized)
+    ? (normalized as SupportedLocale)
+    : null
+}

packages/ports/src/household-config.ts

@@ -1,3 +1,5 @@
+import type { SupportedLocale } from '@household/domain'
+
 export const HOUSEHOLD_TOPIC_ROLES = ['purchase', 'feedback', 'reminders'] as const
 
 export type HouseholdTopicRole = (typeof HOUSEHOLD_TOPIC_ROLES)[number]
@@ -8,6 +10,7 @@ export interface HouseholdTelegramChatRecord {
   telegramChatId: string
   telegramChatType: string
   title: string | null
+  defaultLocale: SupportedLocale
 }
 
 export interface HouseholdTopicBindingRecord {
@@ -31,6 +34,7 @@ export interface HouseholdPendingMemberRecord {
   displayName: string
   username: string | null
   languageCode: string | null
+  householdDefaultLocale: SupportedLocale
 }
 
 export interface HouseholdMemberRecord {
@@ -38,6 +42,8 @@ export interface HouseholdMemberRecord {
   householdId: string
   telegramUserId: string
   displayName: string
+  preferredLocale: SupportedLocale | null
+  householdDefaultLocale: SupportedLocale
   isAdmin: boolean
 }
 
@@ -99,6 +105,7 @@ export interface HouseholdConfigurationRepository {
     householdId: string
     telegramUserId: string
     displayName: string
+    preferredLocale?: SupportedLocale | null
     isAdmin?: boolean
   }): Promise<HouseholdMemberRecord>
   getHouseholdMember(
@@ -115,4 +122,13 @@ export interface HouseholdConfigurationRepository {
     telegramUserId: string
     isAdmin?: boolean
   }): Promise<HouseholdMemberRecord | null>
+  updateHouseholdDefaultLocale(
+    householdId: string,
+    locale: SupportedLocale
+  ): Promise<HouseholdTelegramChatRecord>
+  updateMemberPreferredLocale(
+    householdId: string,
+    telegramUserId: string,
+    locale: SupportedLocale
+  ): Promise<HouseholdMemberRecord | null>
 }