diff --git a/scripts/verify-attachment-storage-model.mjs b/scripts/verify-attachment-storage-model.mjs
new file mode 100644
index 0000000..b505089
--- /dev/null
+++ b/scripts/verify-attachment-storage-model.mjs
@@ -0,0 +1,80 @@
+#!/usr/bin/env node
+import { mkdtemp, copyFile } from "node:fs/promises";
+import { existsSync } from "node:fs";
+import os from "node:os";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import { createRequire } from "node:module";
+
+const rootDir = process.cwd();
+const scriptDir = path.dirname(fileURLToPath(import.meta.url));
+const require = createRequire(import.meta.url);
+const jiti = require("jiti")(fileURLToPath(import.meta.url), {
+  alias: {
+    "@/": `${path.join(rootDir, "src")}/`,
+  },
+});
+
+const tempDir = await mkdtemp(path.join(os.tmpdir(), "boss-attachment-model-"));
+const tempStateFile = path.join(tempDir, "boss-state.json");
+const sourceStateFile = path.join(rootDir, "data", "boss-state.json");
+
+if (!existsSync(sourceStateFile)) {
+  throw new Error(`Missing state file: ${sourceStateFile}`);
+}
+
+await copyFile(sourceStateFile, tempStateFile);
+process.env.BOSS_STATE_FILE = tempStateFile;
+process.env.BOSS_RUNTIME_ROOT = rootDir;
+
+const { getAttachmentStorageConfig, readState, writeState } = jiti(path.join(scriptDir, "..", "src", "lib", "boss-data.ts"));
+
+const config = await getAttachmentStorageConfig("17600003315");
+if (config.mode !== "server_file") {
+  throw new Error(`Expected default storage mode server_file, got ${config.mode}`);
+}
+if (!config.updatedAt || typeof config.updatedAt !== "string") {
+  throw new Error("Expected updatedAt to be populated");
+}
+
+const state = await readState();
+const messageId = "script-attachment-message";
+state.projects[0].messages.unshift({
+  id: messageId,
+  sender: "user",
+  senderLabel: "测试用户",
+  body: "Attachment round-trip",
+  sentAt: "2026-03-29T00:00:00+08:00",
+  kind: "attachment",
+  attachments: [
+    {
+      attachmentId: "att-001",
+      fileName: "demo.txt",
+      mimeType: "text/plain",
+      fileSizeBytes: 12,
+      attachmentKind: "text",
+      storageBackend: "server_file",
+      storagePath: "/tmp/demo.txt",
+      previewAvailable: true,
+      uploadedAt: "2026-03-29T00:00:00+08:00",
+      uploadedBy: "17600003315",
+      analysisState: "not_applicable",
+    },
+  ],
+});
+
+await writeState(state);
+const reread = await readState();
+const message = reread.projects[0].messages.find((item) => item.id === messageId);
+
+if (!message?.attachments?.length) {
+  throw new Error("Expected message attachments to round-trip through state");
+}
+if (message.attachments[0].attachmentId !== "att-001") {
+  throw new Error("Expected attachment metadata to persist");
+}
+if (message.attachments[0].storageBackend !== "server_file") {
+  throw new Error("Expected attachment storage backend to persist");
+}
+
+console.log("OK");
diff --git a/src/lib/boss-data.ts b/src/lib/boss-data.ts
index 100f526..fd324f0 100644
--- a/src/lib/boss-data.ts
+++ b/src/lib/boss-data.ts
@@ -173,6 +173,7 @@ export interface Message {
   body: string;
   sentAt: string;
   kind?: MessageKind;
+  attachments?: MessageAttachment[];
   forwardSource?: ForwardSource;
   forwardBundle?: ForwardBundlePayload;
 }
@@ -1065,7 +1066,7 @@ const initialState: BossState = {
     {
       account: PRIMARY_ADMIN_ACCOUNT,
       mode: "server_file",
-      updatedAt: "2026-03-29T00:00:00+08:00",
+      updatedAt: nowIso(),
     },
   ],
   masterAgentTasks: [],
@@ -1894,11 +1895,32 @@ function normalizeMessage(raw: Partial<Message>): Message {
     body: raw.body ?? "",
     sentAt: raw.sentAt ?? nowIso(),
     kind: raw.kind ?? "text",
+    attachments: Array.isArray(raw.attachments)
+      ? raw.attachments.map((attachment) => normalizeMessageAttachment(attachment))
+      : undefined,
     forwardSource: raw.forwardSource,
     forwardBundle: raw.forwardBundle,
   };
 }
 
+function normalizeMessageAttachment(raw: Partial<MessageAttachment>): MessageAttachment {
+  return {
+    attachmentId: raw.attachmentId ?? randomToken("att"),
+    fileName: raw.fileName ?? "",
+    mimeType: raw.mimeType ?? "application/octet-stream",
+    fileSizeBytes: raw.fileSizeBytes ?? 0,
+    attachmentKind: raw.attachmentKind ?? "binary",
+    storageBackend: raw.storageBackend ?? "server_file",
+    storagePath: raw.storagePath ?? "",
+    previewAvailable: raw.previewAvailable ?? false,
+    uploadedAt: raw.uploadedAt ?? nowIso(),
+    uploadedBy: raw.uploadedBy ?? "system",
+    analysisState: raw.analysisState ?? "not_applicable",
+    analysisSummary: raw.analysisSummary,
+    analysisCardId: raw.analysisCardId,
+  };
+}
+
 function normalizeAttachmentStorageConfig(
   raw: Partial<UserAttachmentStorageConfig>,
   fallback: UserAttachmentStorageConfig,
@@ -2661,26 +2683,15 @@ export async function readState(): Promise<BossState> {
 
   try {
     const state = normalizeState(JSON.parse(raw) as Partial<BossState>);
-    const normalizedText = JSON.stringify(state, null, 2);
-    lastPersistedStateText = normalizedText;
-    if (normalizedText !== raw) {
-      await fs.writeFile(dataFile, normalizedText, "utf8");
-      await fs.writeFile(backupFile, normalizedText, "utf8");
-    }
+    lastPersistedStateText = JSON.stringify(state, null, 2);
     return state;
   } catch {
     const fallbackText =
       (await fs.readFile(backupFile, "utf8").catch(() => null)) ??
       lastPersistedStateText ??
       JSON.stringify(syncDerivedState(cloneInitialState()), null, 2);
-    await fs.writeFile(dataFile, fallbackText, "utf8");
     const state = normalizeState(JSON.parse(fallbackText) as Partial<BossState>);
-    const normalizedText = JSON.stringify(state, null, 2);
-    lastPersistedStateText = normalizedText;
-    if (normalizedText !== fallbackText) {
-      await fs.writeFile(dataFile, normalizedText, "utf8");
-      await fs.writeFile(backupFile, normalizedText, "utf8");
-    }
+    lastPersistedStateText = JSON.stringify(state, null, 2);
     return state;
   }
 }