diff --git a/src/data/repositories/chat_local_message_store.ts b/src/data/repositories/chat_local_message_store.ts
new file mode 100644
index 00000000..4dc96611
--- /dev/null
+++ b/src/data/repositories/chat_local_message_store.ts
@@ -0,0 +1,108 @@
+"use client";
+
+import type { ChatLockDetailData } from "@/data/schemas/chat";
+import { ChatMessage } from "@/data/dto/chat";
+import { LocalChatStorage, LocalMessage } from "@/data/storage/chat";
+import { Result } from "@/utils";
+
+export class ChatLocalMessageStore {
+  constructor(private readonly localStorage: LocalChatStorage) {}
+
+  async markMessageUnlocked(
+    messageId: string,
+    content: string,
+    lockDetail?: ChatLockDetailData,
+  ): Promise<Result<void>> {
+    return Result.wrap(async () => {
+      const localResult = await this.getMessages();
+      if (Result.isErr(localResult)) {
+        throw localResult.error;
+      }
+
+      let changed = false;
+      const updatedMessages = localResult.data.map((message) => {
+        if (message.id !== messageId) return message;
+        changed = true;
+        return ChatMessage.from({
+          ...message.toJson(),
+          content,
+          lockDetail: lockDetail ?? {
+            ...message.lockDetail,
+            locked: false,
+            showContent: true,
+            showUpgrade: false,
+            reason: null,
+            hint: null,
+            detail: null,
+          },
+        });
+      });
+
+      if (!changed) return;
+
+      const saveResult = await this.saveMessages(updatedMessages);
+      if (Result.isErr(saveResult)) {
+        throw saveResult.error;
+      }
+    });
+  }
+
+  async saveMessage(message: ChatMessage): Promise<Result<void>> {
+    return this.localStorage.saveMessage(this._chatToLocal(message));
+  }
+
+  async saveMessages(
+    messages: readonly ChatMessage[],
+  ): Promise<Result<void>> {
+    const cleared = await this.localStorage.clearAll();
+    if (!cleared.success) {
+      return Result.err(cleared.error);
+    }
+    return this.localStorage.saveMessages(
+      messages.map((message) => this._chatToLocal(message)),
+    );
+  }
+
+  async getMessages(): Promise<Result<ChatMessage[]>> {
+    const result = await this.localStorage.getAllMessages();
+    if (!result.success) {
+      return Result.err(result.error);
+    }
+    return Result.ok(result.data.map((message) => this._localToChat(message)));
+  }
+
+  async clearMessages(): Promise<Result<void>> {
+    return this.localStorage.clearAll();
+  }
+
+  async getMessageCount(): Promise<Result<number>> {
+    return this.localStorage.getMessageCount();
+  }
+
+  private _chatToLocal(message: ChatMessage): LocalMessage {
+    return LocalMessage.from({
+      id: message.id,
+      role: message.role,
+      type: message.type,
+      content: message.content,
+      createdAt: message.createdAt,
+      audioUrl: message.audioUrl,
+      image: message.image,
+      lockDetail: message.lockDetail,
+      sessionId: "",
+    });
+  }
+
+  private _localToChat(local: LocalMessage): ChatMessage {
+    return ChatMessage.from({
+      id: local.id,
+      role: local.role,
+      type: local.type,
+      content: local.content,
+      createdAt: local.createdAt,
+      audioUrl: local.audioUrl,
+      image: local.image,
+      lockDetail: local.lockDetail,
+    });
+  }
+}
diff --git a/src/data/repositories/chat_media_cache_coordinator.ts b/src/data/repositories/chat_media_cache_coordinator.ts
new file mode 100644
index 00000000..132a7c04
--- /dev/null
+++ b/src/data/repositories/chat_media_cache_coordinator.ts
@@ -0,0 +1,169 @@
+"use client";
+
+import type { ChatMessage, ChatSendResponse } from "@/data/dto/chat";
+import {
+  LocalChatMediaStorage,
+  type LocalChatMediaRow,
+} from "@/data/storage/chat";
+import { AuthStorage } from "@/data/storage/auth";
+import { UserStorage } from "@/data/storage/user/user_storage";
+import { requestBrowserPersistentStorageOnce } from "@/lib/browser/persistent_storage";
+import { Logger, Result } from "@/utils";
+import type {
+  CacheRemoteChatMediaInput,
+  ChatMediaLookupInput,
+} from "@/data/repositories/interfaces";
+
+import {
+  buildChatMediaCacheKey,
+  fallbackChatMediaMimeType,
+  getMessageMediaTargets,
+  getSendResponseMediaTargets,
+  isCacheableRemoteChatMediaUrl,
+  uniqueMediaTargets,
+} from "./chat_media_cache_helpers";
+
+const log = new Logger("DataRepositoriesChatMediaCacheCoordinator");
+
+export class ChatMediaCacheCoordinator {
+  constructor(private readonly mediaStorage: LocalChatMediaStorage) {}
+
+  async getCachedMedia(
+    input: ChatMediaLookupInput,
+  ): Promise<Result<LocalChatMediaRow | null>> {
+    return Result.wrap(async () => {
+      const ownerKeys = await this._resolveMediaOwnerKeys();
+      for (const ownerKey of ownerKeys) {
+        const cacheKey = this._buildMediaCacheKey(ownerKey, input);
+        const result = await this.mediaStorage.getMedia(cacheKey);
+        if (Result.isErr(result)) throw result.error;
+        if (result.data) return result.data;
+      }
+      return null;
+    });
+  }
+
+  async cacheRemoteMedia(
+    input: CacheRemoteChatMediaInput,
+  ): Promise<Result<LocalChatMediaRow>> {
+    return Result.wrap(async () => {
+      if (!isCacheableRemoteChatMediaUrl(input.remoteUrl)) {
+        throw new Error(`Unsupported media url: ${input.remoteUrl}`);
+      }
+
+      const ownerKeys = await this._resolveMediaOwnerKeys();
+      const ownerKey = ownerKeys[0] ?? "anonymous";
+      const cacheKey = this._buildMediaCacheKey(ownerKey, input);
+      for (const lookupOwnerKey of ownerKeys) {
+        const lookupCacheKey = this._buildMediaCacheKey(lookupOwnerKey, input);
+        const existingResult = await this.mediaStorage.getMedia(lookupCacheKey);
+        if (Result.isErr(existingResult)) throw existingResult.error;
+        if (existingResult.data) return existingResult.data;
+      }
+
+      const response = await fetch(input.remoteUrl, {
+        method: "GET",
+        cache: "force-cache",
+      });
+      if (!response.ok) {
+        throw new Error(
+          `Media download failed: ${response.status} ${response.statusText}`,
+        );
+      }
+
+      const blob = await response.blob();
+      if (blob.size <= 0) {
+        throw new Error("Media download returned an empty blob.");
+      }
+
+      const saveResult = await this.mediaStorage.saveMedia({
+        cacheKey,
+        ownerKey,
+        messageId: input.messageId,
+        kind: input.kind,
+        remoteUrl: input.remoteUrl,
+        blob,
+        mimeType:
+          blob.type ||
+          response.headers.get("content-type") ||
+          fallbackChatMediaMimeType(input.kind),
+      });
+      if (Result.isErr(saveResult)) throw saveResult.error;
+      void requestBrowserPersistentStorageOnce();
+
+      const savedResult = await this.mediaStorage.getMedia(cacheKey);
+      if (Result.isErr(savedResult)) throw savedResult.error;
+      if (!savedResult.data) {
+        throw new Error("Cached media could not be read after save.");
+      }
+      return savedResult.data;
+    });
+  }
+
+  async prefetchMediaForMessages(
+    messages: readonly ChatMessage[],
+  ): Promise<Result<void>> {
+    return this._prefetchMediaTargets(
+      messages.flatMap((message) => getMessageMediaTargets(message)),
+    );
+  }
+
+  async prefetchMediaForSendResponse(
+    response: ChatSendResponse,
+  ): Promise<Result<void>> {
+    return this._prefetchMediaTargets(getSendResponseMediaTargets(response));
+  }
+
+  private async _prefetchMediaTargets(
+    targets: readonly CacheRemoteChatMediaInput[],
+  ): Promise<Result<void>> {
+    return Result.wrap(async () => {
+      for (const target of uniqueMediaTargets(targets)) {
+        const result = await this.cacheRemoteMedia(target);
+        if (Result.isErr(result)) {
+          log.warn("[chat-media] prefetch failed", {
+            messageId: target.messageId,
+            kind: target.kind,
+            remoteUrl: target.remoteUrl,
+            error: result.error,
+          });
+        }
+      }
+    });
+  }
+
+  private async _resolveMediaOwnerKeys(): Promise<string[]> {
+    const ownerKeys: string[] = [];
+    const userIdResult = await UserStorage.getInstance().getUserId();
+    if (
+      Result.isOk(userIdResult) &&
+      userIdResult.data !== null &&
+      userIdResult.data.length > 0
+    ) {
+      ownerKeys.push(`user:${userIdResult.data}`);
+    }
+
+    const deviceIdResult = await AuthStorage.getInstance().getDeviceId();
+    if (
+      Result.isOk(deviceIdResult) &&
+      deviceIdResult.data !== null &&
+      deviceIdResult.data.length > 0
+    ) {
+      ownerKeys.push(`device:${deviceIdResult.data}`);
+    }
+
+    ownerKeys.push("anonymous");
+    return Array.from(new Set(ownerKeys));
+  }
+
+  private _buildMediaCacheKey(
+    ownerKey: string,
+    input: ChatMediaLookupInput,
+  ): string {
+    return buildChatMediaCacheKey({
+      ownerKey,
+      messageId: input.messageId,
+      kind: input.kind,
+    });
+  }
+}
diff --git a/src/data/repositories/chat_remote_data_source.ts b/src/data/repositories/chat_remote_data_source.ts
new file mode 100644
index 00000000..b047adc4
--- /dev/null
+++ b/src/data/repositories/chat_remote_data_source.ts
@@ -0,0 +1,49 @@
+"use client";
+
+import {
+  ChatHistoryResponse,
+  ChatSendResponse,
+  SendMessageRequest,
+  UnlockHistoryResponse,
+  UnlockPrivateRequest,
+  UnlockPrivateResponse,
+} from "@/data/dto/chat";
+import type { ChatApi } from "@/data/services/api";
+import { Result } from "@/utils";
+
+export class ChatRemoteDataSource {
+  constructor(private readonly api: ChatApi) {}
+
+  async sendMessage(
+    message: string,
+    options?: { image?: string; useWebSocket?: boolean },
+  ): Promise<Result<ChatSendResponse>> {
+    return Result.wrap(async () => {
+      const request = SendMessageRequest.from({
+        message,
+        image: options?.image ?? "",
+        useWebSocket: options?.useWebSocket ?? false,
+      });
+      return await this.api.sendMessage(request);
+    });
+  }
+
+  async getHistory(
+    limit = 50,
+    offset = 0,
+  ): Promise<Result<ChatHistoryResponse>> {
+    return Result.wrap(() => this.api.getHistory(limit, offset));
+  }
+
+  async unlockPrivateMessage(
+    messageId: string,
+  ): Promise<Result<UnlockPrivateResponse>> {
+    return Result.wrap(() =>
+      this.api.unlockPrivateMessage(UnlockPrivateRequest.from({ messageId })),
+    );
+  }
+
+  async unlockHistory(): Promise<Result<UnlockHistoryResponse>> {
+    return Result.wrap(() => this.api.unlockHistory());
+  }
+}
diff --git a/src/data/repositories/chat_repository.ts b/src/data/repositories/chat_repository.ts
index 9f585500..0d011a2c 100644
--- a/src/data/repositories/chat_repository.ts
+++ b/src/data/repositories/chat_repository.ts
@@ -1,48 +1,36 @@
 "use client";
 
-import { ChatApi, chatApi } from "@/data/services/api";
-import {
+import type {
   ChatHistoryResponse,
   ChatMessage,
   ChatSendResponse,
-  SendMessageRequest,
   UnlockHistoryResponse,
-  UnlockPrivateRequest,
   UnlockPrivateResponse,
 } from "@/data/dto/chat";
 import type { ChatLockDetailData } from "@/data/schemas/chat";
-import { AuthStorage } from "@/data/storage/auth";
-import { UserStorage } from "@/data/storage/user/user_storage";
-import { Logger, Result } from "@/utils";
+import { chatApi } from "@/data/services/api";
+import {
+  LocalChatMediaStorage,
+  LocalChatStorage,
+  type LocalChatMediaRow,
+} from "@/data/storage/chat";
 import type {
   CacheRemoteChatMediaInput,
   ChatMediaLookupInput,
   IChatRepository,
 } from "@/data/repositories/interfaces";
-import {
-  LocalChatMediaStorage,
-  LocalChatStorage,
-  LocalMessage,
-  type LocalChatMediaRow,
-} from "@/data/storage/chat";
-import {
-  buildChatMediaCacheKey,
-  fallbackChatMediaMimeType,
-  getMessageMediaTargets,
-  getSendResponseMediaTargets,
-  isCacheableRemoteChatMediaUrl,
-  uniqueMediaTargets,
-} from "./chat_media_cache_helpers";
-import { createLazySingleton } from "./lazy_singleton";
-import { requestBrowserPersistentStorageOnce } from "@/lib/browser/persistent_storage";
+import type { Result } from "@/utils";
 
-const log = new Logger("DataRepositoriesChatRepository");
+import { ChatLocalMessageStore } from "./chat_local_message_store";
+import { ChatMediaCacheCoordinator } from "./chat_media_cache_coordinator";
+import { ChatRemoteDataSource } from "./chat_remote_data_source";
+import { createLazySingleton } from "./lazy_singleton";
 
 export class ChatRepository implements IChatRepository {
   constructor(
-    private readonly api: ChatApi,
-    private readonly localStorage: LocalChatStorage,
-    private readonly mediaStorage: LocalChatMediaStorage,
+    private readonly remote: ChatRemoteDataSource,
+    private readonly localMessages: ChatLocalMessageStore,
+    private readonly mediaCache: ChatMediaCacheCoordinator,
   ) {}
 
   // ============ 远程操作 ============
@@ -52,14 +40,7 @@ export class ChatRepository implements IChatRepository {
     message: string,
     options?: { image?: string; useWebSocket?: boolean },
   ): Promise<Result<ChatSendResponse>> {
-    return Result.wrap(async () => {
-      const request = SendMessageRequest.from({
-        message,
-        image: options?.image ?? "",
-        useWebSocket: options?.useWebSocket ?? false,
-      });
-      return await this.api.sendMessage(request);
-    });
+    return this.remote.sendMessage(message, options);
   }
 
   /** 获取聊天历史，分页参数默认 limit=50, offset=0。 */
@@ -67,21 +48,19 @@ export class ChatRepository implements IChatRepository {
     limit = 50,
     offset = 0,
   ): Promise<Result<ChatHistoryResponse>> {
-    return Result.wrap(() => this.api.getHistory(limit, offset));
+    return this.remote.getHistory(limit, offset);
   }
 
   /** 解锁单条历史付费 / 私密消息。 */
   async unlockPrivateMessage(
     messageId: string,
   ): Promise<Result<UnlockPrivateResponse>> {
-    return Result.wrap(() =>
-      this.api.unlockPrivateMessage(UnlockPrivateRequest.from({ messageId })),
-    );
+    return this.remote.unlockPrivateMessage(messageId);
   }
 
   /** 一键解锁历史锁定消息。 */
   async unlockHistory(): Promise<Result<UnlockHistoryResponse>> {
-    return Result.wrap(() => this.api.unlockHistory());
+    return this.remote.unlockHistory();
   }
 
   /** 把本地缓存中的单条锁定消息标记为已解锁。 */
@@ -90,47 +69,18 @@ export class ChatRepository implements IChatRepository {
     content: string,
     lockDetail?: ChatLockDetailData,
   ): Promise<Result<void>> {
-    return Result.wrap(async () => {
-      const localResult = await this.getLocalMessages();
-      if (Result.isErr(localResult)) {
-        throw localResult.error;
-      }
-
-      let changed = false;
-      const updatedMessages = localResult.data.map((message) => {
-        if (message.id !== messageId) return message;
-        changed = true;
-        return ChatMessage.from({
-          ...message.toJson(),
-          content,
-          lockDetail: lockDetail ?? {
-            ...message.lockDetail,
-            locked: false,
-            showContent: true,
-            showUpgrade: false,
-            reason: null,
-            hint: null,
-            detail: null,
-          },
-        });
-      });
-
-      if (!changed) return;
-
-      const saveResult = await this.saveMessagesToLocal(updatedMessages);
-      if (Result.isErr(saveResult)) {
-        throw saveResult.error;
-      }
-    });
+    return this.localMessages.markMessageUnlocked(
+      messageId,
+      content,
+      lockDetail,
+    );
   }
 
   // ============ 本地（Dexie）操作 ============
 
   /** 把一条消息写入本地存储。 */
   async saveMessageToLocal(message: ChatMessage): Promise<Result<void>> {
-    return this._mapLocalStorageResult(
-      this.localStorage.saveMessage(this._chatToLocal(message)),
-    );
+    return this.localMessages.saveMessage(message);
   }
 
   /**
@@ -140,27 +90,17 @@ export class ChatRepository implements IChatRepository {
   async saveMessagesToLocal(
     messages: readonly ChatMessage[],
   ): Promise<Result<void>> {
-    const cleared = await this.localStorage.clearAll();
-    if (!cleared.success) {
-      return Result.err(cleared.error);
-    }
-    return this._mapLocalStorageResult(
-      this.localStorage.saveMessages(messages.map((m) => this._chatToLocal(m))),
-    );
+    return this.localMessages.saveMessages(messages);
   }
 
   /** 读取所有本地消息，按 dbId 升序。 */
   async getLocalMessages(): Promise<Result<ChatMessage[]>> {
-    const result = await this.localStorage.getAllMessages();
-    if (!result.success) {
-      return Result.err(result.error);
-    }
-    return Result.ok(result.data.map((lm) => this._localToChat(lm)));
+    return this.localMessages.getMessages();
   }
 
   /** 清空本地消息。 */
   async clearLocalMessages(): Promise<Result<void>> {
-    return this._mapLocalStorageResult(this.localStorage.clearAll());
+    return this.localMessages.clearMessages();
   }
 
   /**
@@ -168,7 +108,7 @@ export class ChatRepository implements IChatRepository {
    * 替代 Dart 的同步 `int get localMessageCount`——Dexie 异步 API 决定必须 async。
    */
   async getLocalMessageCount(): Promise<Result<number>> {
-    return this._mapLocalStorageResult(this.localStorage.getMessageCount());
+    return this.localMessages.getMessageCount();
   }
 
   // ============ 本地媒体缓存 ============
@@ -176,182 +116,25 @@ export class ChatRepository implements IChatRepository {
   async getCachedMedia(
     input: ChatMediaLookupInput,
   ): Promise<Result<LocalChatMediaRow | null>> {
-    return Result.wrap(async () => {
-      const ownerKeys = await this._resolveMediaOwnerKeys();
-      for (const ownerKey of ownerKeys) {
-        const cacheKey = this._buildMediaCacheKey(ownerKey, input);
-        const result = await this.mediaStorage.getMedia(cacheKey);
-        if (Result.isErr(result)) throw result.error;
-        if (result.data) return result.data;
-      }
-      return null;
-    });
+    return this.mediaCache.getCachedMedia(input);
   }
 
   async cacheRemoteMedia(
     input: CacheRemoteChatMediaInput,
   ): Promise<Result<LocalChatMediaRow>> {
-    return Result.wrap(async () => {
-      if (!isCacheableRemoteChatMediaUrl(input.remoteUrl)) {
-        throw new Error(`Unsupported media url: ${input.remoteUrl}`);
-      }
-
-      const ownerKeys = await this._resolveMediaOwnerKeys();
-      const ownerKey = ownerKeys[0] ?? "anonymous";
-      const cacheKey = this._buildMediaCacheKey(ownerKey, input);
-      for (const lookupOwnerKey of ownerKeys) {
-        const lookupCacheKey = this._buildMediaCacheKey(lookupOwnerKey, input);
-        const existingResult = await this.mediaStorage.getMedia(lookupCacheKey);
-        if (Result.isErr(existingResult)) throw existingResult.error;
-        if (existingResult.data) return existingResult.data;
-      }
-
-      const response = await fetch(input.remoteUrl, {
-        method: "GET",
-        cache: "force-cache",
-      });
-      if (!response.ok) {
-        throw new Error(
-          `Media download failed: ${response.status} ${response.statusText}`,
-        );
-      }
-
-      const blob = await response.blob();
-      if (blob.size <= 0) {
-        throw new Error("Media download returned an empty blob.");
-      }
-
-      const saveResult = await this.mediaStorage.saveMedia({
-        cacheKey,
-        ownerKey,
-        messageId: input.messageId,
-        kind: input.kind,
-        remoteUrl: input.remoteUrl,
-        blob,
-        mimeType:
-          blob.type ||
-          response.headers.get("content-type") ||
-          fallbackChatMediaMimeType(input.kind),
-      });
-      if (Result.isErr(saveResult)) throw saveResult.error;
-      void requestBrowserPersistentStorageOnce();
-
-      const savedResult = await this.mediaStorage.getMedia(cacheKey);
-      if (Result.isErr(savedResult)) throw savedResult.error;
-      if (!savedResult.data) {
-        throw new Error("Cached media could not be read after save.");
-      }
-      return savedResult.data;
-    });
+    return this.mediaCache.cacheRemoteMedia(input);
   }
 
   async prefetchMediaForMessages(
     messages: readonly ChatMessage[],
   ): Promise<Result<void>> {
-    return this._prefetchMediaTargets(
-      messages.flatMap((message) => getMessageMediaTargets(message)),
-    );
+    return this.mediaCache.prefetchMediaForMessages(messages);
   }
 
   async prefetchMediaForSendResponse(
     response: ChatSendResponse,
   ): Promise<Result<void>> {
-    return this._prefetchMediaTargets(getSendResponseMediaTargets(response));
-  }
-
-  // ============ 私有助手 ============
-
-  /** ChatMessage → LocalMessage：丢弃 wire 字段，注入 storage 层的 sessionId=""。 */
-  private _chatToLocal(message: ChatMessage): LocalMessage {
-    return LocalMessage.from({
-      id: message.id,
-      role: message.role,
-      type: message.type,
-      content: message.content,
-      createdAt: message.createdAt,
-      audioUrl: message.audioUrl,
-      image: message.image,
-      lockDetail: message.lockDetail,
-      sessionId: "",
-    });
-  }
-
-  /** LocalMessage → ChatMessage：丢弃 storage 层的 sessionId。 */
-  private _localToChat(local: LocalMessage): ChatMessage {
-    return ChatMessage.from({
-      id: local.id,
-      role: local.role,
-      type: local.type,
-      content: local.content,
-      createdAt: local.createdAt,
-      audioUrl: local.audioUrl,
-      image: local.image,
-      lockDetail: local.lockDetail,
-    });
-  }
-
-  /**
-   * 把 storage 层 `Result<T>` 透传：仓库与 storage 现在共享同一全局
-   * `Result<T>`（来自 `@/utils/result`），不需要任何形状转换。
-   * 该方法保留仅为未来万一又出现差异化时方便快速插入适配。
-   */
-  private async _mapLocalStorageResult<T>(
-    promise: Promise<Result<T>>,
-  ): Promise<Result<T>> {
-    return await promise;
-  }
-
-  private async _prefetchMediaTargets(
-    targets: readonly CacheRemoteChatMediaInput[],
-  ): Promise<Result<void>> {
-    return Result.wrap(async () => {
-      for (const target of uniqueMediaTargets(targets)) {
-        const result = await this.cacheRemoteMedia(target);
-        if (Result.isErr(result)) {
-          log.warn("[chat-media] prefetch failed", {
-            messageId: target.messageId,
-            kind: target.kind,
-            remoteUrl: target.remoteUrl,
-            error: result.error,
-          });
-        }
-      }
-    });
-  }
-
-  private async _resolveMediaOwnerKeys(): Promise<string[]> {
-    const ownerKeys: string[] = [];
-    const userIdResult = await UserStorage.getInstance().getUserId();
-    if (
-      Result.isOk(userIdResult) &&
-      userIdResult.data !== null &&
-      userIdResult.data.length > 0
-    ) {
-      ownerKeys.push(`user:${userIdResult.data}`);
-    }
-
-    const deviceIdResult = await AuthStorage.getInstance().getDeviceId();
-    if (
-      Result.isOk(deviceIdResult) &&
-      deviceIdResult.data !== null &&
-      deviceIdResult.data.length > 0
-    ) {
-      ownerKeys.push(`device:${deviceIdResult.data}`);
-    }
-
-    ownerKeys.push("anonymous");
-    return Array.from(new Set(ownerKeys));
-  }
-
-  private _buildMediaCacheKey(
-    ownerKey: string,
-    input: ChatMediaLookupInput,
-  ): string {
-    return buildChatMediaCacheKey({
-      ownerKey,
-      messageId: input.messageId,
-      kind: input.kind,
-    });
+    return this.mediaCache.prefetchMediaForSendResponse(response);
   }
 }
 
@@ -359,8 +142,8 @@ export class ChatRepository implements IChatRepository {
 export const getChatRepository = createLazySingleton<IChatRepository>(
   () =>
     new ChatRepository(
-      chatApi,
-      LocalChatStorage.getInstance(),
-      LocalChatMediaStorage.getInstance(),
+      new ChatRemoteDataSource(chatApi),
+      new ChatLocalMessageStore(LocalChatStorage.getInstance()),
+      new ChatMediaCacheCoordinator(LocalChatMediaStorage.getInstance()),
     ),
 );
diff --git a/src/stores/chat/chat-flow-actions.ts b/src/stores/chat/chat-flow-actions.ts
new file mode 100644
index 00000000..e83aef44
--- /dev/null
+++ b/src/stores/chat/chat-flow-actions.ts
@@ -0,0 +1,13 @@
+import { assign as xAssign } from "xstate";
+
+import type { ChatEvent } from "./chat-events";
+import type { ChatState } from "./chat-state";
+
+export type ChatActionArgs = { context: ChatState; event: ChatEvent };
+export type ChatContextArgs = { context: ChatState };
+
+export const chatAssign = (
+  assignment: Parameters<
+    typeof xAssign<ChatState, ChatEvent, undefined, ChatEvent, never>
+  >[0],
+) => xAssign<ChatState, ChatEvent, undefined, ChatEvent, never>(assignment);
diff --git a/src/stores/chat/chat-history-flow.ts b/src/stores/chat/chat-history-flow.ts
new file mode 100644
index 00000000..99a3db85
--- /dev/null
+++ b/src/stores/chat/chat-history-flow.ts
@@ -0,0 +1,51 @@
+import { fromPromise } from "xstate";
+
+import { getChatRepository } from "@/data/repositories/chat_repository";
+import { Logger, Result } from "@/utils";
+
+import {
+  PAGE_SIZE,
+  localMessagesToUi,
+  readAndSyncHistory,
+} from "./chat-machine.helpers";
+
+const log = new Logger("StoresChatChatHistoryFlow");
+
+type UiMessage = import("@/data/dto/chat").UiMessage;
+
+export const chatHistoryActors = {
+  loadHistory: fromPromise<{
+    messages: UiMessage[];
+    hasMore: boolean;
+    newOffset: number;
+    localOverwritten: boolean;
+    localCount: number;
+    networkCount: number;
+  }>(async () => {
+    return readAndSyncHistory();
+  }),
+
+  loadMoreHistory: fromPromise<
+    { messages: UiMessage[]; hasMore: boolean; newOffset: number },
+    { offset: number }
+  >(async ({ input }) => {
+    const chatRepo = getChatRepository();
+    const result = await chatRepo.getHistory(PAGE_SIZE, input.offset);
+    if (Result.isErr(result)) {
+      log.error("[chat-machine] loadMoreHistoryActor failed", {
+        error: result.error,
+      });
+      throw result.error;
+    }
+    const page = localMessagesToUi(result.data.messages);
+    void chatRepo.prefetchMediaForMessages(result.data.messages);
+    return {
+      messages: page,
+      hasMore: page.length >= PAGE_SIZE,
+      newOffset: input.offset + page.length,
+    };
+  }),
+};
+
+export const loadHistoryActor = chatHistoryActors.loadHistory;
+export const loadMoreHistoryActor = chatHistoryActors.loadMoreHistory;
diff --git a/src/stores/chat/chat-machine.actors.ts b/src/stores/chat/chat-machine.actors.ts
index b8858553..7e57e31a 100644
--- a/src/stores/chat/chat-machine.actors.ts
+++ b/src/stores/chat/chat-machine.actors.ts
@@ -1,227 +1,24 @@
 /**
- * Chat 状态机：history / send / queue actors
+ * Backward-compatible actor exports.
+ *
+ * Concrete implementations live in capability flow files:
+ * - chat-history-flow
+ * - chat-send-flow
+ * - chat-unlock-flow
  */
-
-import { fromPromise, fromCallback } from "xstate";
-
-import { MessageQueue } from "@/core/net/message-queue";
-import type { ChatLockDetailData } from "@/data/schemas/chat";
-import type { ChatSendResponse, UnlockPrivateResponse } from "@/data/dto/chat";
-import { getChatRepository } from "@/data/repositories/chat_repository";
-import { Result, Logger } from "@/utils";
-
-import {
-  PAGE_SIZE,
-  localMessagesToUi,
-  readAndSyncHistory,
-  sendResponseToUiMessage,
-} from "./chat-machine.helpers";
-import type { ChatEvent } from "./chat-events";
-
-const log = new Logger("StoresChatChatMachineActors");
-
-// ============================================================
-// Init 任务 2：拉 history 3 步流（fromPromise，返回最终结果）
-// ============================================================
-/**
- * local → network → save network to local 3 步流（返回 network 最终 messages）
- * - 选方案 A（fromPromise）：UI 不会看到 local 中间态，直接显示 network 结果
- * - 内部 3 步走 helper `readAndSyncHistory`（日志全在 helper 里）
- * - 失败返 local（退而求其次）
- */
-export const loadHistoryActor = fromPromise<{
-  messages: UiMessage[];
-  hasMore: boolean;
-  newOffset: number;
-  localOverwritten: boolean;
-  localCount: number;
-  networkCount: number;
-}>(async () => {
-  return readAndSyncHistory();
-});
-
-// ============================================================
-// HTTP: one-shot Promise
-// ============================================================
-/**
- * HTTP 发送消息（一次发送 = 一次返回）
- * - 后端响应就是 AI 回复（`ChatSendResponse.reply: string`）
- * - 不再调 `getLocalMessages()`（多此一举）
- * - 返回完整 response + 可追加的 reply，方便处理后端 lockDetail 响应
- */
-export const sendMessageHttpActor = fromPromise<
-  { response: ChatSendResponse; reply: UiMessage | null },
-  { content: string }
->(async ({ input }) => {
-  return sendMessageViaHttp(input.content);
-});
-
-/** 翻历史（pagination）—— 不走 local-first，纯 server fetch */
-export const loadMoreHistoryActor = fromPromise<
-  { messages: UiMessage[]; hasMore: boolean; newOffset: number },
-  { offset: number }
->(async ({ input }) => {
-  const chatRepo = getChatRepository();
-  const result = await chatRepo.getHistory(PAGE_SIZE, input.offset);
-  if (Result.isErr(result)) {
-    log.error("[chat-machine] loadMoreHistoryActor failed", { error: result.error });
-    throw result.error;
-  }
-  const page = localMessagesToUi(result.data.messages);
-  void chatRepo.prefetchMediaForMessages(result.data.messages);
-  return {
-    messages: page,
-    hasMore: page.length >= PAGE_SIZE,
-    newOffset: input.offset + page.length,
-  };
-});
-
-export const unlockHistoryActor = fromPromise<{
-  unlocked: boolean;
-  reason: string;
-  shortfallCredits: number;
-  messages: UiMessage[];
-  hasMore: boolean;
-  newOffset: number;
-}>(async () => {
-  const chatRepo = getChatRepository();
-  const unlockResult = await chatRepo.unlockHistory();
-  if (Result.isErr(unlockResult)) {
-    log.error("[chat-machine] unlockHistoryActor failed", {
-      error: unlockResult.error,
-    });
-    throw unlockResult.error;
-  }
-
-  const history = await readAndSyncHistory();
-  return {
-    unlocked: unlockResult.data.unlocked,
-    reason: unlockResult.data.reason,
-    shortfallCredits: unlockResult.data.shortfallCredits,
-    messages: history.messages,
-    hasMore: history.hasMore,
-    newOffset: history.newOffset,
-  };
-});
-
-export interface UnlockMessageOutput {
-  messageId: string;
-  response: UnlockPrivateResponse;
-}
-
-export const unlockMessageActor = fromPromise<
-  UnlockMessageOutput,
-  { messageId: string }
->(async ({ input }) => {
-  const chatRepo = getChatRepository();
-  const unlockResult = await chatRepo.unlockPrivateMessage(input.messageId);
-  if (Result.isErr(unlockResult)) {
-    log.error("[chat-machine] unlockMessageActor failed", {
-      messageId: input.messageId,
-      error: unlockResult.error,
-    });
-    throw unlockResult.error;
-  }
-
-  if (unlockResult.data.unlocked) {
-    const markResult = await chatRepo.markPrivateMessageUnlockedInLocal(
-      input.messageId,
-      unlockResult.data.content,
-      unlockResult.data.lockDetail as ChatLockDetailData,
-    );
-    if (Result.isErr(markResult)) {
-      log.warn("[chat-machine] mark unlocked local message failed", {
-        messageId: input.messageId,
-        error: markResult.error,
-      });
-    }
-  }
-
-  return {
-    messageId: input.messageId,
-    response: unlockResult.data,
-  };
-});
-
-export const httpMessageQueueActor = fromCallback<ChatEvent>(
-  ({ sendBack, receive }) => {
-    return createMessageQueueActor(sendBack, receive);
-  },
-);
-
-function createMessageQueueActor(
-  sendBack: (event: ChatEvent) => void,
-  receive: (listener: (event: ChatEvent) => void) => void,
-): () => void {
-  const queue = new MessageQueue();
-
-  queue.setConsumer(async (content) => {
-    sendBack({ type: "ChatQueuedSendStarted" });
-    try {
-      const output = await sendMessageViaHttp(content);
-      sendBack({ type: "ChatQueuedHttpDone", output });
-    } catch (error) {
-      const errorMessage =
-        error instanceof Error ? error.message : "Message send failed";
-      log.error("[chat-machine] message queue send failed", {
-        error,
-      });
-      sendBack({
-        type: "ChatQueuedSendError",
-        content,
-        errorMessage,
-      });
-    }
-  });
-
-  receive((event) => {
-    if (event.type !== "ChatSendMessage") return;
-    const content = event.content.trim();
-    if (content.length === 0) return;
-    queue.enqueue(content);
-  });
-
-  return () => queue.dispose();
-}
-
-// Re-export `UiMessage` type for the chat-machine.ts public API
-type UiMessage = import("@/data/dto/chat").UiMessage;
-
-async function sendMessageViaHttp(content: string): Promise<{
-  response: ChatSendResponse;
-  reply: UiMessage | null;
-}> {
-  const chatRepo = getChatRepository();
-  const result = await chatRepo.sendMessage(content);
-  if (Result.isErr(result)) {
-    log.error("[chat-machine] sendMessageHttpActor failed", { error: result.error });
-    throw result.error;
-  }
-  void chatRepo.prefetchMediaForSendResponse(result.data);
-  const isMessageLimit =
-    result.data.lockDetail.locked &&
-    result.data.lockDetail.showUpgrade &&
-    result.data.lockDetail.reason === "weekly_limit";
-  const isInsufficientCredits =
-    result.data.canSendMessage === false &&
-    result.data.cannotSendReason === "insufficient_credits" &&
-    !hasRenderableSendResponse(result.data);
-  return {
-    response: result.data,
-    reply:
-      isMessageLimit || isInsufficientCredits
-        ? null
-        : sendResponseToUiMessage(result.data),
-  };
-}
-
-function hasRenderableSendResponse(response: ChatSendResponse): boolean {
-  return (
-    response.reply.trim().length > 0 ||
-    response.audioUrl.trim().length > 0 ||
-    Boolean(response.image.url) ||
-    response.lockDetail.reason === "private_message" ||
-    response.lockDetail.reason === "voice_message" ||
-    response.lockDetail.reason === "image_paywall"
-  );
-}
+export {
+  chatHistoryActors,
+  loadHistoryActor,
+  loadMoreHistoryActor,
+} from "./chat-history-flow";
+export {
+  chatSendActors,
+  httpMessageQueueActor,
+  sendMessageHttpActor,
+} from "./chat-send-flow";
+export {
+  chatUnlockActors,
+  unlockHistoryActor,
+  unlockMessageActor,
+  type UnlockMessageOutput,
+} from "./chat-unlock-flow";
diff --git a/src/stores/chat/chat-machine.helpers.ts b/src/stores/chat/chat-machine.helpers.ts
index 478c7580..2906bfcb 100644
--- a/src/stores/chat/chat-machine.helpers.ts
+++ b/src/stores/chat/chat-machine.helpers.ts
@@ -1,5 +1,4 @@
-import type { UiMessage } from "@/data/dto/chat";
-import type { UnlockMessageOutput } from "./chat-machine.actors";
+import type { UiMessage, UnlockPrivateResponse } from "@/data/dto/chat";
 import { getChatRepository } from "@/data/repositories/chat_repository";
 import { ChatSendResponse } from "@/data/dto/chat/chat_send_response";
 import { todayString, Result, Logger } from "@/utils";
@@ -143,6 +142,11 @@ export type HttpSendOutput = {
   reply: UiMessage | null;
 };
 
+export interface UnlockMessageOutput {
+  messageId: string;
+  response: UnlockPrivateResponse;
+}
+
 export function applySingleUnlockOutput(
   messages: readonly UiMessage[],
   output: UnlockMessageOutput,
diff --git a/src/stores/chat/chat-machine.ts b/src/stores/chat/chat-machine.ts
index fb602f0c..673015af 100644
--- a/src/stores/chat/chat-machine.ts
+++ b/src/stores/chat/chat-machine.ts
@@ -29,31 +29,19 @@
 
 import { setup, assign, sendTo } from "xstate";
 
-import { todayString, Logger } from "@/utils";
-
 import { ChatState, initialState } from "./chat-state";
 import type { ChatEvent } from "./chat-events";
 import {
   applyHttpSendOutput,
   applyHistoryLoadedOutput,
-  applySingleUnlockOutput,
-  beginPendingReply,
   countLockedHistoryMessages,
-  finishPendingReply,
   shouldAutoUnlockHistory,
   shouldPromptUnlockHistory,
 } from "./chat-machine.helpers";
-import {
-  loadHistoryActor,
-  sendMessageHttpActor,
-  loadMoreHistoryActor,
-  httpMessageQueueActor,
-  unlockHistoryActor,
-  unlockMessageActor,
-  type UnlockMessageOutput,
-} from "./chat-machine.actors";
-
-const log = new Logger("StoresChatChatMachine");
+import { chatHistoryActors } from "./chat-history-flow";
+import { chatMediaActions } from "./chat-media-flow";
+import { chatSendActions, chatSendActors } from "./chat-send-flow";
+import { chatUnlockActions, chatUnlockActors } from "./chat-unlock-flow";
 
 // 重新导出 State / Event 类型，保持 machine 文件的公共 API 不变
 export type { ChatState } from "./chat-state";
@@ -69,14 +57,14 @@ export const chatMachine = setup({
     events: {} as ChatEvent,
   },
   actors: {
-    loadHistory: loadHistoryActor,
-    sendMessageHttp: sendMessageHttpActor,
-    loadMoreHistory: loadMoreHistoryActor,
-    httpMessageQueue: httpMessageQueueActor,
-    unlockHistory: unlockHistoryActor,
-    unlockMessage: unlockMessageActor,
+    ...chatHistoryActors,
+    ...chatSendActors,
+    ...chatUnlockActors,
   },
   actions: {
+    ...chatSendActions,
+    ...chatMediaActions,
+    ...chatUnlockActions,
     enqueueMessage: sendTo("messageQueue", ({ event }) => event),
 
     startGuestSession: assign(() => ({
@@ -90,234 +78,6 @@ export const chatMachine = setup({
     clearChatSession: assign(() => ({
       ...initialState,
     })),
-
-    appendGuestUserMessage: assign(({ context, event }) => {
-      if (event.type !== "ChatSendMessage") return {};
-
-      const today = todayString();
-      log.debug("[chat-machine] appendGuestUserMessage", {
-        contentLength: event.content.length,
-        contentPreview: event.content.slice(0, 50),
-        quotaMode: "server controlled",
-        isReplyingAI: context.isReplyingAI,
-      });
-
-      return {
-        messages: [
-          ...context.messages,
-          {
-            content: event.content,
-            isFromAI: false,
-            date: today,
-          },
-        ],
-        upgradePromptVisible: false,
-        upgradeReason: null,
-      };
-    }),
-
-    appendUserMessage: assign(({ context, event }) => {
-      if (event.type !== "ChatSendMessage") return {};
-
-      const today = todayString();
-      log.debug("[chat-machine] appendUserMessage", {
-        contentLength: event.content.length,
-        contentPreview: event.content.slice(0, 50),
-        isReplyingAI: context.isReplyingAI,
-      });
-
-      return {
-        messages: [
-          ...context.messages,
-          {
-            content: event.content,
-            isFromAI: false,
-            date: today,
-          },
-        ],
-        upgradePromptVisible: false,
-        upgradeReason: null,
-      };
-    }),
-
-    appendGuestUserImage: assign(({ context, event }) => {
-      if (event.type !== "ChatSendImage") return {};
-
-      const today = todayString();
-      log.debug("[chat-machine] appendGuestUserImage", {
-        oldMessagesCount: context.messages.length,
-        quotaMode: "server controlled",
-      });
-      return {
-        messages: [
-          ...context.messages,
-          {
-            content: "[Image]",
-            isFromAI: false,
-            date: today,
-            imageUrl: event.imageBase64,
-          },
-        ],
-        ...beginPendingReply(context),
-        upgradePromptVisible: false,
-        upgradeReason: null,
-      };
-    }),
-
-    appendUserImage: assign(({ context, event }) => {
-      if (event.type !== "ChatSendImage") return {};
-
-      const today = todayString();
-      log.debug("[chat-machine] appendUserImage", {
-        oldMessagesCount: context.messages.length,
-      });
-
-      return {
-        messages: [
-          ...context.messages,
-          {
-            content: "[Image]",
-            isFromAI: false,
-            date: today,
-            imageUrl: event.imageBase64,
-          },
-        ],
-        ...beginPendingReply(context),
-        upgradePromptVisible: false,
-        upgradeReason: null,
-      };
-    }),
-
-    appendQueuedSendErrorMessage: assign(({ context }) => {
-      const messages = [
-        ...context.messages,
-        {
-          content: "Something went wrong. Try sending again?",
-          isFromAI: true,
-          date: todayString(),
-        },
-      ];
-      return { messages, ...finishPendingReply(context) };
-    }),
-
-    markQueuedSendStarted: assign(({ context }) => beginPendingReply(context)),
-
-    applyQueuedHttpOutput: assign(({ context, event }) => {
-      if (event.type !== "ChatQueuedHttpDone") return {};
-      return applyHttpSendOutput(context, event.output);
-    }),
-
-    clearUpgradePrompt: assign(() => ({
-      upgradePromptVisible: false,
-      upgradeReason: null,
-      canSendMessage: true,
-      cannotSendReason: null,
-      requiredCredits: 0,
-      shortfallCredits: 0,
-    })),
-
-    markPaymentUnlockPending: assign(() => ({
-      paymentUnlockPending: true,
-      unlockHistoryError: null,
-    })),
-
-    showUnlockHistoryPrompt: assign(({ context }) => ({
-      paymentUnlockPending: false,
-      unlockHistoryPromptVisible: true,
-      lockedHistoryCount: countLockedHistoryMessages(context.messages),
-      unlockHistoryError: null,
-    })),
-
-    dismissUnlockHistoryPrompt: assign(() => ({
-      paymentUnlockPending: false,
-      unlockHistoryPromptVisible: false,
-      unlockHistoryError: null,
-    })),
-
-    markUnlockHistoryStarted: assign(() => ({
-      paymentUnlockPending: false,
-      unlockHistoryPromptVisible: false,
-      isUnlockingHistory: true,
-      unlockHistoryError: null,
-    })),
-
-    markUnlockHistoryFailed: assign(() => ({
-      isUnlockingHistory: false,
-      unlockHistoryPromptVisible: true,
-      unlockHistoryError: "Failed to unlock messages. Please try again.",
-    })),
-
-    markUnlockMessageStarted: assign(({ event }) => {
-      if (event.type !== "ChatUnlockMessageRequested") return {};
-      return {
-        isUnlockingMessage: true,
-        unlockingMessageId: event.messageId,
-        unlockingMessageKind: event.kind,
-        unlockMessageError: null,
-        unlockPaywallRequest: null,
-      };
-    }),
-
-    applyUnlockMessageSucceeded: assign(({ context, event }) => {
-      const output = (event as { output?: UnlockMessageOutput }).output;
-      if (!output) return {};
-      return {
-        messages: applySingleUnlockOutput(context.messages, output),
-        isUnlockingMessage: false,
-        unlockingMessageId: null,
-        unlockingMessageKind: null,
-        unlockMessageError: null,
-        unlockPaywallRequest: null,
-        creditBalance: output.response.creditBalance,
-        creditsCharged: output.response.creditsCharged,
-        requiredCredits: 0,
-        shortfallCredits: 0,
-      };
-    }),
-
-    requestUnlockPaymentFromOutput: assign(({ context, event }) => {
-      const output = (event as { output?: UnlockMessageOutput }).output;
-      if (!output) return {};
-      return {
-        isUnlockingMessage: false,
-        unlockingMessageId: null,
-        unlockingMessageKind: null,
-        unlockMessageError: output.response.reason,
-        unlockPaywallRequest: {
-          messageId: output.messageId,
-          kind: context.unlockingMessageKind ?? "private",
-          reason: output.response.reason,
-          creditBalance: output.response.creditBalance,
-          requiredCredits: output.response.requiredCredits,
-          shortfallCredits: output.response.shortfallCredits,
-        },
-        creditBalance: output.response.creditBalance,
-        requiredCredits: output.response.requiredCredits,
-        shortfallCredits: output.response.shortfallCredits,
-      };
-    }),
-
-    requestUnlockPaymentFromError: assign(({ context }) => ({
-      isUnlockingMessage: false,
-      unlockMessageError: "unlock_failed",
-      unlockPaywallRequest:
-        context.unlockingMessageId && context.unlockingMessageKind
-          ? {
-              messageId: context.unlockingMessageId,
-              kind: context.unlockingMessageKind,
-              reason: "unlock_failed",
-              creditBalance: context.creditBalance,
-              requiredCredits: context.requiredCredits,
-              shortfallCredits: context.shortfallCredits,
-            }
-          : null,
-      unlockingMessageId: null,
-      unlockingMessageKind: null,
-    })),
-
-    clearUnlockPaywallRequest: assign(() => ({
-      unlockPaywallRequest: null,
-    })),
   },
 }).createMachine({
   id: "chat",
diff --git a/src/stores/chat/chat-media-flow.ts b/src/stores/chat/chat-media-flow.ts
new file mode 100644
index 00000000..7a76cb06
--- /dev/null
+++ b/src/stores/chat/chat-media-flow.ts
@@ -0,0 +1,56 @@
+import { Logger, todayString } from "@/utils";
+
+import { chatAssign, type ChatActionArgs } from "./chat-flow-actions";
+import { beginPendingReply } from "./chat-machine.helpers";
+
+const log = new Logger("StoresChatChatMediaFlow");
+
+export const chatMediaActions = {
+  appendGuestUserImage: chatAssign(({ context, event }: ChatActionArgs) => {
+    if (event.type !== "ChatSendImage") return {};
+
+    const today = todayString();
+    log.debug("[chat-machine] appendGuestUserImage", {
+      oldMessagesCount: context.messages.length,
+      quotaMode: "server controlled",
+    });
+    return {
+      messages: [
+        ...context.messages,
+        {
+          content: "[Image]",
+          isFromAI: false,
+          date: today,
+          imageUrl: event.imageBase64,
+        },
+      ],
+      ...beginPendingReply(context),
+      upgradePromptVisible: false,
+      upgradeReason: null,
+    };
+  }),
+
+  appendUserImage: chatAssign(({ context, event }: ChatActionArgs) => {
+    if (event.type !== "ChatSendImage") return {};
+
+    const today = todayString();
+    log.debug("[chat-machine] appendUserImage", {
+      oldMessagesCount: context.messages.length,
+    });
+
+    return {
+      messages: [
+        ...context.messages,
+        {
+          content: "[Image]",
+          isFromAI: false,
+          date: today,
+          imageUrl: event.imageBase64,
+        },
+      ],
+      ...beginPendingReply(context),
+      upgradePromptVisible: false,
+      upgradeReason: null,
+    };
+  }),
+};
diff --git a/src/stores/chat/chat-send-flow.ts b/src/stores/chat/chat-send-flow.ts
new file mode 100644
index 00000000..a54244d8
--- /dev/null
+++ b/src/stores/chat/chat-send-flow.ts
@@ -0,0 +1,196 @@
+import { fromCallback, fromPromise } from "xstate";
+
+import { MessageQueue } from "@/core/net/message-queue";
+import type { ChatSendResponse } from "@/data/dto/chat";
+import { getChatRepository } from "@/data/repositories/chat_repository";
+import { Logger, Result, todayString } from "@/utils";
+
+import type { ChatEvent } from "./chat-events";
+import {
+  chatAssign,
+  type ChatActionArgs,
+  type ChatContextArgs,
+} from "./chat-flow-actions";
+import {
+  applyHttpSendOutput,
+  beginPendingReply,
+  finishPendingReply,
+  sendResponseToUiMessage,
+} from "./chat-machine.helpers";
+
+const log = new Logger("StoresChatChatSendFlow");
+
+type UiMessage = import("@/data/dto/chat").UiMessage;
+
+export const chatSendActors = {
+  sendMessageHttp: fromPromise<
+    { response: ChatSendResponse; reply: UiMessage | null },
+    { content: string }
+  >(async ({ input }) => {
+    return sendMessageViaHttp(input.content);
+  }),
+
+  httpMessageQueue: fromCallback<ChatEvent>(({ sendBack, receive }) => {
+    return createMessageQueueActor(sendBack, receive);
+  }),
+};
+
+export const chatSendActions = {
+  appendGuestUserMessage: chatAssign(({ context, event }: ChatActionArgs) => {
+    if (event.type !== "ChatSendMessage") return {};
+
+    const today = todayString();
+    log.debug("[chat-machine] appendGuestUserMessage", {
+      contentLength: event.content.length,
+      contentPreview: event.content.slice(0, 50),
+      quotaMode: "server controlled",
+      isReplyingAI: context.isReplyingAI,
+    });
+
+    return {
+      messages: [
+        ...context.messages,
+        {
+          content: event.content,
+          isFromAI: false,
+          date: today,
+        },
+      ],
+      upgradePromptVisible: false,
+      upgradeReason: null,
+    };
+  }),
+
+  appendUserMessage: chatAssign(({ context, event }: ChatActionArgs) => {
+    if (event.type !== "ChatSendMessage") return {};
+
+    const today = todayString();
+    log.debug("[chat-machine] appendUserMessage", {
+      contentLength: event.content.length,
+      contentPreview: event.content.slice(0, 50),
+      isReplyingAI: context.isReplyingAI,
+    });
+
+    return {
+      messages: [
+        ...context.messages,
+        {
+          content: event.content,
+          isFromAI: false,
+          date: today,
+        },
+      ],
+      upgradePromptVisible: false,
+      upgradeReason: null,
+    };
+  }),
+
+  appendQueuedSendErrorMessage: chatAssign(({ context }: ChatContextArgs) => {
+    const messages = [
+      ...context.messages,
+      {
+        content: "Something went wrong. Try sending again?",
+        isFromAI: true,
+        date: todayString(),
+      },
+    ];
+    return { messages, ...finishPendingReply(context) };
+  }),
+
+  markQueuedSendStarted: chatAssign(({ context }: ChatContextArgs) =>
+    beginPendingReply(context),
+  ),
+
+  applyQueuedHttpOutput: chatAssign(({ context, event }: ChatActionArgs) => {
+    if (event.type !== "ChatQueuedHttpDone") return {};
+    return applyHttpSendOutput(context, event.output);
+  }),
+
+  clearUpgradePrompt: chatAssign(() => ({
+    upgradePromptVisible: false,
+    upgradeReason: null,
+    canSendMessage: true,
+    cannotSendReason: null,
+    requiredCredits: 0,
+    shortfallCredits: 0,
+  })),
+};
+
+export const sendMessageHttpActor = chatSendActors.sendMessageHttp;
+export const httpMessageQueueActor = chatSendActors.httpMessageQueue;
+
+function createMessageQueueActor(
+  sendBack: (event: ChatEvent) => void,
+  receive: (listener: (event: ChatEvent) => void) => void,
+): () => void {
+  const queue = new MessageQueue();
+
+  queue.setConsumer(async (content) => {
+    sendBack({ type: "ChatQueuedSendStarted" });
+    try {
+      const output = await sendMessageViaHttp(content);
+      sendBack({ type: "ChatQueuedHttpDone", output });
+    } catch (error) {
+      const errorMessage =
+        error instanceof Error ? error.message : "Message send failed";
+      log.error("[chat-machine] message queue send failed", {
+        error,
+      });
+      sendBack({
+        type: "ChatQueuedSendError",
+        content,
+        errorMessage,
+      });
+    }
+  });
+
+  receive((event) => {
+    if (event.type !== "ChatSendMessage") return;
+    const content = event.content.trim();
+    if (content.length === 0) return;
+    queue.enqueue(content);
+  });
+
+  return () => queue.dispose();
+}
+
+async function sendMessageViaHttp(content: string): Promise<{
+  response: ChatSendResponse;
+  reply: UiMessage | null;
+}> {
+  const chatRepo = getChatRepository();
+  const result = await chatRepo.sendMessage(content);
+  if (Result.isErr(result)) {
+    log.error("[chat-machine] sendMessageHttpActor failed", {
+      error: result.error,
+    });
+    throw result.error;
+  }
+  void chatRepo.prefetchMediaForSendResponse(result.data);
+  const isMessageLimit =
+    result.data.lockDetail.locked &&
+    result.data.lockDetail.showUpgrade &&
+    result.data.lockDetail.reason === "weekly_limit";
+  const isInsufficientCredits =
+    result.data.canSendMessage === false &&
+    result.data.cannotSendReason === "insufficient_credits" &&
+    !hasRenderableSendResponse(result.data);
+  return {
+    response: result.data,
+    reply:
+      isMessageLimit || isInsufficientCredits
+        ? null
+        : sendResponseToUiMessage(result.data),
+  };
+}
+
+function hasRenderableSendResponse(response: ChatSendResponse): boolean {
+  return (
+    response.reply.trim().length > 0 ||
+    response.audioUrl.trim().length > 0 ||
+    Boolean(response.image.url) ||
+    response.lockDetail.reason === "private_message" ||
+    response.lockDetail.reason === "voice_message" ||
+    response.lockDetail.reason === "image_paywall"
+  );
+}
diff --git a/src/stores/chat/chat-unlock-flow.ts b/src/stores/chat/chat-unlock-flow.ts
new file mode 100644
index 00000000..e1d3ebc3
--- /dev/null
+++ b/src/stores/chat/chat-unlock-flow.ts
@@ -0,0 +1,192 @@
+import { fromPromise } from "xstate";
+
+import { getChatRepository } from "@/data/repositories/chat_repository";
+import { Logger, Result } from "@/utils";
+
+import {
+  chatAssign,
+  type ChatActionArgs,
+  type ChatContextArgs,
+} from "./chat-flow-actions";
+import {
+  applySingleUnlockOutput,
+  countLockedHistoryMessages,
+  readAndSyncHistory,
+  type UnlockMessageOutput,
+} from "./chat-machine.helpers";
+
+const log = new Logger("StoresChatChatUnlockFlow");
+
+type UiMessage = import("@/data/dto/chat").UiMessage;
+
+export const chatUnlockActors = {
+  unlockHistory: fromPromise<{
+    unlocked: boolean;
+    reason: string;
+    shortfallCredits: number;
+    messages: UiMessage[];
+    hasMore: boolean;
+    newOffset: number;
+  }>(async () => {
+    const chatRepo = getChatRepository();
+    const unlockResult = await chatRepo.unlockHistory();
+    if (Result.isErr(unlockResult)) {
+      log.error("[chat-machine] unlockHistoryActor failed", {
+        error: unlockResult.error,
+      });
+      throw unlockResult.error;
+    }
+
+    const history = await readAndSyncHistory();
+    return {
+      unlocked: unlockResult.data.unlocked,
+      reason: unlockResult.data.reason,
+      shortfallCredits: unlockResult.data.shortfallCredits,
+      messages: history.messages,
+      hasMore: history.hasMore,
+      newOffset: history.newOffset,
+    };
+  }),
+
+  unlockMessage: fromPromise<UnlockMessageOutput, { messageId: string }>(
+    async ({ input }) => {
+      const chatRepo = getChatRepository();
+      const unlockResult = await chatRepo.unlockPrivateMessage(input.messageId);
+      if (Result.isErr(unlockResult)) {
+        log.error("[chat-machine] unlockMessageActor failed", {
+          messageId: input.messageId,
+          error: unlockResult.error,
+        });
+        throw unlockResult.error;
+      }
+
+      if (unlockResult.data.unlocked) {
+        const markResult = await chatRepo.markPrivateMessageUnlockedInLocal(
+          input.messageId,
+          unlockResult.data.content,
+          unlockResult.data.lockDetail,
+        );
+        if (Result.isErr(markResult)) {
+          log.warn("[chat-machine] mark unlocked local message failed", {
+            messageId: input.messageId,
+            error: markResult.error,
+          });
+        }
+      }
+
+      return {
+        messageId: input.messageId,
+        response: unlockResult.data,
+      };
+    },
+  ),
+};
+
+export const chatUnlockActions = {
+  markPaymentUnlockPending: chatAssign(() => ({
+    paymentUnlockPending: true,
+    unlockHistoryError: null,
+  })),
+
+  showUnlockHistoryPrompt: chatAssign(({ context }: ChatContextArgs) => ({
+    paymentUnlockPending: false,
+    unlockHistoryPromptVisible: true,
+    lockedHistoryCount: countLockedHistoryMessages(context.messages),
+    unlockHistoryError: null,
+  })),
+
+  dismissUnlockHistoryPrompt: chatAssign(() => ({
+    paymentUnlockPending: false,
+    unlockHistoryPromptVisible: false,
+    unlockHistoryError: null,
+  })),
+
+  markUnlockHistoryStarted: chatAssign(() => ({
+    paymentUnlockPending: false,
+    unlockHistoryPromptVisible: false,
+    isUnlockingHistory: true,
+    unlockHistoryError: null,
+  })),
+
+  markUnlockHistoryFailed: chatAssign(() => ({
+    isUnlockingHistory: false,
+    unlockHistoryPromptVisible: true,
+    unlockHistoryError: "Failed to unlock messages. Please try again.",
+  })),
+
+  markUnlockMessageStarted: chatAssign(({ event }: ChatActionArgs) => {
+    if (event.type !== "ChatUnlockMessageRequested") return {};
+    return {
+      isUnlockingMessage: true,
+      unlockingMessageId: event.messageId,
+      unlockingMessageKind: event.kind,
+      unlockMessageError: null,
+      unlockPaywallRequest: null,
+    };
+  }),
+
+  applyUnlockMessageSucceeded: chatAssign(({ context, event }: ChatActionArgs) => {
+    const output = (event as { output?: UnlockMessageOutput }).output;
+    if (!output) return {};
+    return {
+      messages: applySingleUnlockOutput(context.messages, output),
+      isUnlockingMessage: false,
+      unlockingMessageId: null,
+      unlockingMessageKind: null,
+      unlockMessageError: null,
+      unlockPaywallRequest: null,
+      creditBalance: output.response.creditBalance,
+      creditsCharged: output.response.creditsCharged,
+      requiredCredits: 0,
+      shortfallCredits: 0,
+    };
+  }),
+
+  requestUnlockPaymentFromOutput: chatAssign(({ context, event }: ChatActionArgs) => {
+    const output = (event as { output?: UnlockMessageOutput }).output;
+    if (!output) return {};
+    return {
+      isUnlockingMessage: false,
+      unlockingMessageId: null,
+      unlockingMessageKind: null,
+      unlockMessageError: output.response.reason,
+      unlockPaywallRequest: {
+        messageId: output.messageId,
+        kind: context.unlockingMessageKind ?? "private",
+        reason: output.response.reason,
+        creditBalance: output.response.creditBalance,
+        requiredCredits: output.response.requiredCredits,
+        shortfallCredits: output.response.shortfallCredits,
+      },
+      creditBalance: output.response.creditBalance,
+      requiredCredits: output.response.requiredCredits,
+      shortfallCredits: output.response.shortfallCredits,
+    };
+  }),
+
+  requestUnlockPaymentFromError: chatAssign(({ context }: ChatContextArgs) => ({
+    isUnlockingMessage: false,
+    unlockMessageError: "unlock_failed",
+    unlockPaywallRequest:
+      context.unlockingMessageId && context.unlockingMessageKind
+        ? {
+            messageId: context.unlockingMessageId,
+            kind: context.unlockingMessageKind,
+            reason: "unlock_failed",
+            creditBalance: context.creditBalance,
+            requiredCredits: context.requiredCredits,
+            shortfallCredits: context.shortfallCredits,
+          }
+        : null,
+    unlockingMessageId: null,
+    unlockingMessageKind: null,
+  })),
+
+  clearUnlockPaywallRequest: chatAssign(() => ({
+    unlockPaywallRequest: null,
+  })),
+};
+
+export const unlockHistoryActor = chatUnlockActors.unlockHistory;
+export const unlockMessageActor = chatUnlockActors.unlockMessage;
+export type { UnlockMessageOutput } from "./chat-machine.helpers";