diff --git a/.ai-project/state.yaml b/.ai-project/state.yaml
index 66bfc26..5e36c2f 100644
--- a/.ai-project/state.yaml
+++ b/.ai-project/state.yaml
@@ -1,7 +1,7 @@
 工作流: "idea-to-product"
 项目: "Great Agent 2"
 版本: "0.3.0"
-当前阶段: "骨架待确认"
+当前阶段: "纵向功能开发"
 更新时间: "2026-08-12"
 阻塞: null
 
@@ -15,12 +15,42 @@
     确认人: "用户"
     确认时间: "2026-08-12"
   项目骨架:
-    状态: "待确认"
-    确认人: null
-    确认时间: null
+    状态: "已确认"
+    确认人: "用户"
+    确认时间: "2026-08-12"
   功能验收:
     状态: "未开始"
     确认人: null
     确认时间: null
 
-功能: []
+功能:
+  - 编号: "F-001"
+    名称: "应用外壳、首次状态与普通会话"
+    状态: "待用户查看"
+  - 编号: "F-002"
+    名称: "Agent Core 与 DeepSeek 流式回复"
+    状态: "待开始"
+  - 编号: "F-003"
+    名称: "项目管理与项目聊天"
+    状态: "待开始"
+  - 编号: "F-004"
+    名称: "用户交互卡片"
+    状态: "待开始"
+  - 编号: "F-005"
+    名称: "停止、失败与重试"
+    状态: "待开始"
+  - 编号: "F-006"
+    名称: "附件、文件列表、读取与搜索"
+    状态: "待开始"
+  - 编号: "F-007"
+    名称: "文件创建与安全修改"
+    状态: "待开始"
+  - 编号: "F-008"
+    名称: "会话管理与个人设置"
+    状态: "待开始"
+  - 编号: "F-009"
+    名称: "Claude Desktop 视觉与交互收口"
+    状态: "待开始"
+  - 编号: "F-010"
+    名称: "恢复、边界与发布前加固"
+    状态: "待开始"
diff --git a/AGENTS.md b/AGENTS.md
index 0a3c1c7..a2296e0 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -22,6 +22,7 @@
 - 不得扩大已经冻结的当前版本范围。
 - 新想法记录到后续版本。
 - 每次只开发一个完整的纵向功能切片。
+- 每个纵向功能切片完成并验证后必须暂停，通知用户查看；只有用户明确确认当前切片后，才能把下一切片标记为“进行中”或开始实现。
 - 每个切片覆盖所有适用的界面、接口或服务、数据持久化、权限、校验、异常状态、日志和测试。
 - 修改前先检查现有代码。
 - 实际运行项目规定的格式或静态检查、类型检查、测试和生产构建。
@@ -34,5 +35,6 @@
 - 保持 `local file -> agent core -> web serve -> web` 的依赖方向。
 - Agent Core 不得依赖 Web 层，为后续 `local file -> agent core -> cli` 保留扩展边界。
 - 避免大文件；模块按单一职责拆分。出现同时承担协议、业务和存储职责的文件时必须拆分。
+- Web 组件私有样式与对应组件文件放在同一目录，例如 `sidebar.ts` 对应 `sidebar.css`；`styles/` 只保存设计令牌、全局 reset 和确实跨组件的基础样式，不创建与功能目录重复的样式镜像树。
 - 当前版本为单人使用，不引入多租户、多用户或分布式并发设计。
 - 访问保护由部署环境中的外部反向代理承担；应用内不得实现登录页面、身份校验中间件、用户会话或访问凭据配置。
diff --git a/apps/web-server/src/composition/create-app.ts b/apps/web-server/src/composition/create-app.ts
index a0d16be..910ff58 100644
--- a/apps/web-server/src/composition/create-app.ts
+++ b/apps/web-server/src/composition/create-app.ts
@@ -3,11 +3,17 @@ import type { Logger } from "pino";
 import { createErrorHandler } from "../http/error-handler";
 import { requestId } from "../http/request-id";
 import { createHealthRoutes } from "../routes/health";
+import { createConversationRoutes } from "../routes/conversations";
+import type { ConversationService } from "@great-agent/agent-core";
 
-export function createApp(logger: Logger): Hono {
+export function createApp(
+  logger: Logger,
+  conversations?: ConversationService,
+): Hono {
   const app = new Hono();
   app.use("*", requestId);
   app.onError(createErrorHandler(logger));
   app.route("/api", createHealthRoutes());
+  if (conversations) app.route("/api", createConversationRoutes(conversations));
   return app;
 }
diff --git a/apps/web-server/src/http/error-handler.ts b/apps/web-server/src/http/error-handler.ts
index 8bf92ff..fafc944 100644
--- a/apps/web-server/src/http/error-handler.ts
+++ b/apps/web-server/src/http/error-handler.ts
@@ -1,9 +1,30 @@
 import type { ErrorHandler } from "hono";
 import type { Logger } from "pino";
+import { CoreError } from "@great-agent/agent-core";
+import { ZodError } from "zod";
 
 export function createErrorHandler(logger: Logger): ErrorHandler {
   return (error, context) => {
     const requestId = context.get("requestId") ?? crypto.randomUUID();
+    if (error instanceof ZodError) {
+      return context.json(
+        {
+          error: {
+            code: "REQUEST_INVALID",
+            message: "请求内容无效",
+            requestId,
+          },
+        },
+        400,
+      );
+    }
+    if (error instanceof CoreError) {
+      const status = error.code === "CONVERSATION_NOT_FOUND" ? 404 : 400;
+      return context.json(
+        { error: { code: error.code, message: error.message, requestId } },
+        status,
+      );
+    }
     logger.error({ error, requestId }, "请求处理失败");
     return context.json(
       {
diff --git a/apps/web-server/src/index.ts b/apps/web-server/src/index.ts
index 4e3c316..ed3fe1f 100644
--- a/apps/web-server/src/index.ts
+++ b/apps/web-server/src/index.ts
@@ -1,5 +1,10 @@
 import { resolve } from "node:path";
-import { createDataLayout, ensureDataLayout } from "@great-agent/local-data";
+import {
+  FileConversationRepository,
+  createDataLayout,
+  ensureDataLayout,
+} from "@great-agent/local-data";
+import { ConversationService } from "@great-agent/agent-core";
 import { createApp } from "./composition/create-app";
 import { createLogger } from "./composition/create-logger";
 import { mountStaticWeb } from "./composition/static-web";
@@ -10,7 +15,12 @@ const logger = createLogger(environment.logLevel);
 const layout = createDataLayout(environment.dataDir);
 await ensureDataLayout(layout);
 
-const app = createApp(logger);
+const conversations = new ConversationService({
+  conversations: new FileConversationRepository(layout),
+  clock: { now: () => new Date() },
+  ids: { create: () => crypto.randomUUID() },
+});
+const app = createApp(logger, conversations);
 mountStaticWeb(app, resolve(import.meta.dir, "../../web/dist"));
 
 logger.info(
diff --git a/apps/web-server/src/routes/conversations.test.ts b/apps/web-server/src/routes/conversations.test.ts
new file mode 100644
index 0000000..9521c7e
--- /dev/null
+++ b/apps/web-server/src/routes/conversations.test.ts
@@ -0,0 +1,70 @@
+import { describe, expect, test } from "bun:test";
+import pino from "pino";
+import {
+  ConversationService,
+  type Conversation,
+  type ConversationRepository,
+} from "@great-agent/agent-core";
+import { createApp } from "../composition/create-app";
+
+class MemoryRepository implements ConversationRepository {
+  private readonly values = new Map<string, Conversation>();
+  async listRecent() {
+    return [...this.values.values()];
+  }
+  async getById(id: string) {
+    return this.values.get(id) ?? null;
+  }
+  async create(value: Conversation) {
+    this.values.set(value.id, value);
+  }
+  async appendMessage(id: string, message: Conversation["messages"][number]) {
+    const current = this.values.get(id);
+    if (!current) throw new Error("not found");
+    const next = {
+      ...current,
+      messages: [...current.messages, message],
+      updatedAt: message.createdAt,
+    };
+    this.values.set(id, next);
+    return next;
+  }
+}
+
+function createTestApp() {
+  let id = 0;
+  const service = new ConversationService({
+    conversations: new MemoryRepository(),
+    clock: { now: () => new Date("2026-08-12T00:00:00.000Z") },
+    ids: { create: () => `id_${++id}` },
+  });
+  return createApp(pino({ enabled: false }), service);
+}
+
+describe("普通会话路由", () => {
+  test("首条消息创建会话并可读取", async () => {
+    const app = createTestApp();
+    const created = await app.request("/api/conversations", {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: JSON.stringify({ content: "你好" }),
+    });
+    expect(created.status).toBe(201);
+    const conversation = (await created.json()) as Conversation;
+    expect(
+      (await app.request(`/api/conversations/${conversation.id}`)).status,
+    ).toBe(200);
+    expect(await (await app.request("/api/conversations")).json()).toHaveLength(
+      1,
+    );
+  });
+
+  test("拒绝空消息", async () => {
+    const response = await createTestApp().request("/api/conversations", {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: JSON.stringify({ content: " " }),
+    });
+    expect(response.status).toBe(400);
+  });
+});
diff --git a/apps/web-server/src/routes/conversations.ts b/apps/web-server/src/routes/conversations.ts
new file mode 100644
index 0000000..25fa298
--- /dev/null
+++ b/apps/web-server/src/routes/conversations.ts
@@ -0,0 +1,27 @@
+import { Hono } from "hono";
+import type { ConversationService } from "@great-agent/agent-core";
+import { messageInputSchema } from "@great-agent/web-contracts";
+
+export function createConversationRoutes(service: ConversationService): Hono {
+  const routes = new Hono();
+  routes.get("/conversations", async (context) =>
+    context.json(await service.listRecent()),
+  );
+  routes.get("/conversations/:id", async (context) =>
+    context.json(await service.getConversation(context.req.param("id"))),
+  );
+  routes.post("/conversations", async (context) => {
+    const input = messageInputSchema.parse(await context.req.json());
+    return context.json(
+      await service.createWithFirstMessage(input.content),
+      201,
+    );
+  });
+  routes.post("/conversations/:id/messages", async (context) => {
+    const input = messageInputSchema.parse(await context.req.json());
+    return context.json(
+      await service.appendUserMessage(context.req.param("id"), input.content),
+    );
+  });
+  return routes;
+}
diff --git a/apps/web/src/api/conversations.ts b/apps/web/src/api/conversations.ts
new file mode 100644
index 0000000..fef81b2
--- /dev/null
+++ b/apps/web/src/api/conversations.ts
@@ -0,0 +1,69 @@
+import {
+  conversationSchema,
+  conversationSummarySchema,
+  type ConversationResponse,
+  type ConversationSummaryResponse,
+} from "@great-agent/web-contracts";
+
+export async function listConversations(): Promise<
+  ConversationSummaryResponse[]
+> {
+  return conversationSummarySchema
+    .array()
+    .parse(await request("/api/conversations"));
+}
+
+export async function getConversation(
+  id: string,
+): Promise<ConversationResponse> {
+  return conversationSchema.parse(
+    await request(`/api/conversations/${encodeURIComponent(id)}`),
+  );
+}
+
+export async function createConversation(
+  content: string,
+): Promise<ConversationResponse> {
+  return conversationSchema.parse(
+    await request("/api/conversations", {
+      method: "POST",
+      body: JSON.stringify({ content }),
+    }),
+  );
+}
+
+export async function appendMessage(
+  id: string,
+  content: string,
+): Promise<ConversationResponse> {
+  return conversationSchema.parse(
+    await request(`/api/conversations/${encodeURIComponent(id)}/messages`, {
+      method: "POST",
+      body: JSON.stringify({ content }),
+    }),
+  );
+}
+
+async function request(path: string, init?: RequestInit): Promise<unknown> {
+  const response = await fetch(path, {
+    ...init,
+    headers: { "content-type": "application/json", ...init?.headers },
+  });
+  const value = await response.json();
+  if (!response.ok) throw new Error(readErrorMessage(value));
+  return value;
+}
+
+function readErrorMessage(value: unknown): string {
+  if (typeof value === "object" && value && "error" in value) {
+    const error = value.error;
+    if (
+      typeof error === "object" &&
+      error &&
+      "message" in error &&
+      typeof error.message === "string"
+    )
+      return error.message;
+  }
+  return "请求失败，请稍后重试";
+}
diff --git a/apps/web/src/app/app-controller.ts b/apps/web/src/app/app-controller.ts
new file mode 100644
index 0000000..ad61e96
--- /dev/null
+++ b/apps/web/src/app/app-controller.ts
@@ -0,0 +1,106 @@
+import van, { type State } from "vanjs-core";
+import type {
+  ConversationResponse,
+  ConversationSummaryResponse,
+} from "@great-agent/web-contracts";
+import {
+  appendMessage,
+  createConversation,
+  getConversation,
+  listConversations,
+} from "../api/conversations";
+
+export type Selection =
+  | { kind: "none" }
+  | { kind: "ordinary-draft" }
+  | { kind: "conversation"; id: string };
+
+export type AppController = Readonly<{
+  selection: State<Selection>;
+  recent: State<ConversationSummaryResponse[]>;
+  active: State<ConversationResponse | null>;
+  loading: State<boolean>;
+  sending: State<boolean>;
+  error: State<string>;
+  initialize(): Promise<void>;
+  startNewTask(): void;
+  openConversation(id: string): Promise<void>;
+  send(content: string): Promise<void>;
+}>;
+
+export function createAppController(): AppController {
+  const selection = van.state<Selection>({ kind: "none" });
+  const recent = van.state<ConversationSummaryResponse[]>([]);
+  const active = van.state<ConversationResponse | null>(null);
+  const loading = van.state(false);
+  const sending = van.state(false);
+  const error = van.state("");
+
+  async function initialize() {
+    loading.val = true;
+    error.val = "";
+    try {
+      recent.val = await listConversations();
+    } catch (cause) {
+      error.val = readMessage(cause);
+    } finally {
+      loading.val = false;
+    }
+  }
+
+  function startNewTask() {
+    selection.val = { kind: "ordinary-draft" };
+    active.val = null;
+    error.val = "";
+  }
+
+  async function openConversation(id: string) {
+    loading.val = true;
+    error.val = "";
+    try {
+      active.val = await getConversation(id);
+      selection.val = { kind: "conversation", id };
+    } catch (cause) {
+      error.val = readMessage(cause);
+    } finally {
+      loading.val = false;
+    }
+  }
+
+  async function send(content: string) {
+    if (!content.trim() || sending.val) return;
+    sending.val = true;
+    error.val = "";
+    try {
+      const current = selection.val;
+      const conversation =
+        current.kind === "conversation"
+          ? await appendMessage(current.id, content)
+          : await createConversation(content);
+      active.val = conversation;
+      selection.val = { kind: "conversation", id: conversation.id };
+      recent.val = await listConversations();
+    } catch (cause) {
+      error.val = readMessage(cause);
+    } finally {
+      sending.val = false;
+    }
+  }
+
+  return {
+    selection,
+    recent,
+    active,
+    loading,
+    sending,
+    error,
+    initialize,
+    startNewTask,
+    openConversation,
+    send,
+  };
+}
+
+function readMessage(cause: unknown): string {
+  return cause instanceof Error ? cause.message : "操作失败，请重试";
+}
diff --git a/apps/web/src/app/app-shell.css b/apps/web/src/app/app-shell.css
new file mode 100644
index 0000000..b3f0662
--- /dev/null
+++ b/apps/web/src/app/app-shell.css
@@ -0,0 +1,12 @@
+.app-shell {
+  display: grid;
+  grid-template-columns: var(--sidebar-width) minmax(0, 1fr);
+  min-height: 100vh;
+  background: var(--color-canvas);
+}
+
+@media (max-width: 700px) {
+  .app-shell {
+    grid-template-columns: 1fr;
+  }
+}
diff --git a/apps/web/src/app/app-shell.ts b/apps/web/src/app/app-shell.ts
index 0a047dd..84d94bd 100644
--- a/apps/web/src/app/app-shell.ts
+++ b/apps/web/src/app/app-shell.ts
@@ -1,11 +1,17 @@
 import van from "vanjs-core";
+import { createAppController } from "./app-controller";
+import { Sidebar } from "../features/conversations/sidebar";
+import { ConversationPane } from "../features/conversations/conversation-pane";
+import "./app-shell.css";
 
-const { h1, main, p } = van.tags;
+const { div } = van.tags;
 
 export function AppShell(): HTMLElement {
-  return main(
+  const controller = createAppController();
+  void controller.initialize();
+  return div(
     { class: "app-shell" },
-    h1("Great Agent 2"),
-    p("项目骨架运行正常，产品界面将在纵向功能阶段实现。"),
+    Sidebar(controller),
+    ConversationPane(controller),
   );
 }
diff --git a/apps/web/src/features/conversations/conversation-pane.css b/apps/web/src/features/conversations/conversation-pane.css
new file mode 100644
index 0000000..e79732a
--- /dev/null
+++ b/apps/web/src/features/conversations/conversation-pane.css
@@ -0,0 +1,172 @@
+.main-pane {
+  position: relative;
+  min-width: 0;
+  min-height: 100vh;
+  padding-bottom: 170px;
+  background-color: var(--color-main);
+  background-image: radial-gradient(#2e2e2c 0.65px, transparent 0.65px);
+  background-size: 9px 9px;
+}
+.mobile-header {
+  display: none;
+}
+.onboarding {
+  position: absolute;
+  top: 50%;
+  left: 50%;
+  width: min(var(--composer-width), calc(100% - 40px));
+  transform: translate(-50%, -67%);
+}
+.onboarding h1 {
+  margin: 0;
+  font-family: var(--font-serif);
+  font-size: 25px;
+  font-weight: 600;
+  letter-spacing: -0.02em;
+}
+.onboarding p {
+  margin: 7px 0 0 29px;
+  color: #87837d;
+  font-size: 11px;
+}
+.spark {
+  color: var(--color-accent);
+  font-family: sans-serif;
+  font-size: 23px;
+}
+.conversation-view {
+  width: min(720px, calc(100% - 48px));
+  margin: 0 auto;
+  padding: 55px 0 30px;
+}
+.conversation-title {
+  margin: 0 0 34px;
+  font-family: var(--font-serif);
+  font-size: 24px;
+}
+.message-list {
+  display: grid;
+  gap: 24px;
+}
+.message {
+  display: grid;
+  grid-template-columns: 27px 1fr;
+  gap: 10px;
+}
+.message-role {
+  display: grid;
+  width: 25px;
+  height: 25px;
+  place-items: center;
+  border-radius: 50%;
+  color: #302a27;
+  background: #d08a72;
+  font-size: 11px;
+  font-weight: 700;
+}
+.message p {
+  margin: 2px 0 0;
+  color: #e1ded8;
+  font-size: 14px;
+  line-height: 1.55;
+  white-space: pre-wrap;
+}
+.composer-wrap {
+  position: fixed;
+  right: 0;
+  bottom: 18px;
+  left: var(--sidebar-width);
+  width: min(var(--composer-width), calc(100% - 236px));
+  margin: 0 auto;
+}
+.composer {
+  min-height: 84px;
+  padding: 12px 13px 8px;
+  border: 1px solid var(--color-border);
+  border-radius: 15px 15px 0 0;
+  background: var(--color-panel);
+  box-shadow: 0 14px 40px #0005;
+}
+.composer textarea {
+  display: block;
+  width: 100%;
+  min-height: 43px;
+  padding: 0;
+  resize: none;
+  border: 0;
+  outline: 0;
+  color: #e9e6e0;
+  background: transparent;
+  font-size: 12px;
+}
+.composer textarea::placeholder {
+  color: #8d8982;
+}
+.composer-actions {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+}
+.attach,
+.send {
+  display: grid;
+  width: 25px;
+  height: 25px;
+  place-items: center;
+  border-radius: 7px;
+  background: transparent;
+  font-size: 18px;
+}
+.attach {
+  color: #a29e97;
+}
+.send {
+  color: #fff;
+  background: #a95e4d;
+  font-weight: 700;
+}
+.composer-meta {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  height: 31px;
+  padding: 0 13px;
+  border: 1px solid #363532;
+  border-top: 0;
+  border-radius: 0 0 15px 15px;
+  color: var(--color-text-secondary);
+  background: var(--color-panel-subtle);
+  font-size: 10px;
+}
+.composer-meta button {
+  padding: 0;
+  color: var(--color-text-secondary);
+  background: transparent;
+  font-size: 10px;
+}
+.error-banner {
+  margin-bottom: 7px;
+  padding: 8px 11px;
+  border: 1px solid #7a4038;
+  border-radius: 8px;
+  color: #e4aaa0;
+  background: #3a2522;
+  font-size: 11px;
+}
+
+@media (max-width: 700px) {
+  .mobile-header {
+    display: block;
+    padding: 14px 16px;
+    border-bottom: 1px solid #323230;
+    font-size: 13px;
+  }
+  .composer-wrap {
+    left: 0;
+    width: calc(100% - 24px);
+  }
+  .conversation-view {
+    width: calc(100% - 28px);
+    padding-top: 30px;
+  }
+}
diff --git a/apps/web/src/features/conversations/conversation-pane.ts b/apps/web/src/features/conversations/conversation-pane.ts
new file mode 100644
index 0000000..7d3fe98
--- /dev/null
+++ b/apps/web/src/features/conversations/conversation-pane.ts
@@ -0,0 +1,96 @@
+import van, { type State } from "vanjs-core";
+import type { AppController } from "../../app/app-controller";
+import "./conversation-pane.css";
+
+const { article, button, div, h1, header, main, p, span, textarea } = van.tags;
+
+export function ConversationPane(controller: AppController): HTMLElement {
+  const draft = van.state("");
+
+  async function submit() {
+    const content = draft.val;
+    if (!content.trim()) return;
+    await controller.send(content);
+    if (!controller.error.val) draft.val = "";
+  }
+
+  return main(
+    { class: "main-pane" },
+    header({ class: "mobile-header" }, "Great Agent 2"),
+    () =>
+      controller.selection.val.kind === "conversation" && controller.active.val
+        ? div(
+            { class: "conversation-view" },
+            h1({ class: "conversation-title" }, controller.active.val.title),
+            div(
+              { class: "message-list" },
+              controller.active.val.messages.map((message) =>
+                article(
+                  { class: `message ${message.role}` },
+                  span({ class: "message-role" }, "你"),
+                  p(message.content),
+                ),
+              ),
+            ),
+          )
+        : div(
+            { class: "onboarding" },
+            h1(span({ class: "spark" }, "✳"), " 今天想完成什么？"),
+            p("从一个问题、想法或具体任务开始。"),
+          ),
+    Composer(controller, draft, submit),
+  );
+}
+
+function Composer(
+  controller: AppController,
+  draft: State<string>,
+  submit: () => Promise<void>,
+): HTMLElement {
+  return div(
+    { class: "composer-wrap" },
+    () =>
+      controller.error.val
+        ? div({ class: "error-banner", role: "alert" }, controller.error.val)
+        : null,
+    div(
+      { class: "composer" },
+      textarea({
+        "aria-label": "输入消息",
+        placeholder: "我能帮你做些什么？",
+        value: draft,
+        disabled: controller.sending,
+        oninput: (event: Event) => {
+          draft.val = (event.target as HTMLTextAreaElement).value;
+        },
+        onkeydown: (event: KeyboardEvent) => {
+          if (event.key === "Enter" && !event.shiftKey) {
+            event.preventDefault();
+            void submit();
+          }
+        },
+      }),
+      div(
+        { class: "composer-actions" },
+        button(
+          { class: "attach", disabled: true, "aria-label": "添加附件" },
+          "+",
+        ),
+        button(
+          {
+            class: "send",
+            disabled: () => controller.sending.val || !draft.val.trim(),
+            onclick: () => void submit(),
+            "aria-label": "发送消息",
+          },
+          () => (controller.sending.val ? "…" : "↑"),
+        ),
+      ),
+    ),
+    div(
+      { class: "composer-meta" },
+      button({ disabled: true }, "普通对话"),
+      span("DeepSeek"),
+    ),
+  );
+}
diff --git a/apps/web/src/features/conversations/sidebar.css b/apps/web/src/features/conversations/sidebar.css
new file mode 100644
index 0000000..bf1d9f9
--- /dev/null
+++ b/apps/web/src/features/conversations/sidebar.css
@@ -0,0 +1,140 @@
+.sidebar {
+  position: relative;
+  display: flex;
+  flex-direction: column;
+  min-height: 100vh;
+  padding: 10px 7px;
+  border-right: 1px solid #323230;
+  background: var(--color-sidebar);
+}
+
+.window-controls {
+  display: flex;
+  gap: 8px;
+  height: 19px;
+  padding: 1px 4px;
+}
+.window-controls span {
+  width: 9px;
+  height: 9px;
+  border-radius: 50%;
+  background: #55534f;
+}
+.mode-switch {
+  display: grid;
+  grid-template-columns: 1fr 1fr;
+  gap: 3px;
+  margin: 6px 3px 8px;
+  padding: 2px;
+  border-radius: 7px;
+  background: #2d2d2b;
+}
+.mode-switch button {
+  min-height: 23px;
+  border-radius: 5px;
+  color: #8e8b85;
+  background: transparent;
+  font-size: 11px;
+}
+.mode-switch button.active {
+  color: #e7e4de;
+  background: #42413e;
+}
+.new-task,
+.nav-item {
+  width: 100%;
+  min-height: 29px;
+  padding: 0 9px;
+  border-radius: 6px;
+  text-align: left;
+  background: transparent;
+  font-size: 12px;
+}
+.new-task {
+  background: #1c1c1b;
+}
+.new-task:hover,
+.recent-list button:hover {
+  background: #323230;
+}
+.plus {
+  display: inline-block;
+  width: 19px;
+  font-size: 17px;
+  vertical-align: -1px;
+}
+.nav-item {
+  color: #c8c5bf;
+}
+.sidebar h2 {
+  margin: 14px 7px 6px;
+  color: #77746f;
+  font-size: 10px;
+  font-weight: 500;
+  text-transform: uppercase;
+  letter-spacing: 0.04em;
+}
+.sidebar-empty {
+  padding: 5px 8px;
+  color: #716e69;
+  font-size: 11px;
+}
+.recent-list {
+  display: grid;
+  gap: 1px;
+  margin: 0;
+  padding: 0;
+  list-style: none;
+}
+.recent-list button {
+  overflow: hidden;
+  width: 100%;
+  padding: 6px 10px 6px 20px;
+  border-radius: 5px;
+  color: #b8b5af;
+  background: transparent;
+  text-align: left;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+  font-size: 11px;
+}
+.recent-list button::before {
+  content: "○";
+  margin-left: -13px;
+  margin-right: 6px;
+  color: #5d5a56;
+}
+.sidebar-footer {
+  display: flex;
+  gap: 9px;
+  align-items: center;
+  margin-top: auto;
+  padding: 9px 8px 3px;
+  border-top: 1px solid #302f2e;
+  color: #c8c5bf;
+  font-size: 11px;
+}
+.sidebar-footer div {
+  display: grid;
+  gap: 1px;
+}
+.sidebar-footer div span {
+  color: #77746f;
+  font-size: 9px;
+}
+.avatar {
+  display: grid;
+  width: 25px;
+  height: 25px;
+  place-items: center;
+  border-radius: 50%;
+  color: #1f1e1c;
+  background: #ce7c64;
+  font-weight: 700;
+}
+
+@media (max-width: 700px) {
+  .sidebar {
+    display: none;
+  }
+}
diff --git a/apps/web/src/features/conversations/sidebar.ts b/apps/web/src/features/conversations/sidebar.ts
new file mode 100644
index 0000000..693af0c
--- /dev/null
+++ b/apps/web/src/features/conversations/sidebar.ts
@@ -0,0 +1,45 @@
+import van from "vanjs-core";
+import type { AppController } from "../../app/app-controller";
+import "./sidebar.css";
+
+const { aside, button, div, h2, li, span, ul } = van.tags;
+
+export function Sidebar(controller: AppController): HTMLElement {
+  return aside(
+    { class: "sidebar" },
+    div({ class: "window-controls" }, span(), span(), span()),
+    div(
+      { class: "mode-switch" },
+      button({ class: "active" }, "对话"),
+      button({ disabled: true }, "代码"),
+    ),
+    button(
+      { class: "new-task", onclick: controller.startNewTask },
+      span({ class: "plus" }, "+"),
+      "新任务",
+    ),
+    button({ class: "nav-item", disabled: true }, "▣", " 项目"),
+    h2("最近"),
+    () =>
+      controller.loading.val && controller.recent.val.length === 0
+        ? div({ class: "sidebar-empty" }, "正在加载…")
+        : controller.recent.val.length === 0
+          ? div({ class: "sidebar-empty" }, "暂无对话")
+          : ul(
+              { class: "recent-list" },
+              controller.recent.val.map((item) =>
+                li(
+                  button(
+                    { onclick: () => controller.openConversation(item.id) },
+                    item.title,
+                  ),
+                ),
+              ),
+            ),
+    div(
+      { class: "sidebar-footer" },
+      span({ class: "avatar" }, "G"),
+      div("Great Agent 2", span("本地个人助手")),
+    ),
+  );
+}
diff --git a/apps/web/src/styles/global.css b/apps/web/src/styles/global.css
index 5552612..899af1d 100644
--- a/apps/web/src/styles/global.css
+++ b/apps/web/src/styles/global.css
@@ -1,31 +1,31 @@
-:root {
-  color: #272522;
-  background: #f7f6f2;
-  font-family: ui-sans-serif, system-ui, sans-serif;
-}
+@import "./tokens.css";
 
 * {
   box-sizing: border-box;
 }
 
 body {
-  margin: 0;
-}
-
-.app-shell {
-  display: grid;
+  min-width: 320px;
   min-height: 100vh;
-  place-content: center;
-  padding: 2rem;
-  text-align: center;
-}
-
-.app-shell h1 {
-  margin: 0 0 0.75rem;
-  font-size: 2rem;
-}
-
-.app-shell p {
   margin: 0;
-  color: #6b6760;
+  color: var(--color-text-primary);
+  background: var(--color-canvas);
+  font-family: var(--font-sans);
+  font-synthesis: none;
+}
+
+button,
+textarea {
+  color: inherit;
+  font: inherit;
+}
+
+button {
+  border: 0;
+  cursor: pointer;
+}
+
+button:disabled {
+  cursor: default;
+  opacity: 0.46;
 }
diff --git a/apps/web/src/styles/tokens.css b/apps/web/src/styles/tokens.css
new file mode 100644
index 0000000..798f115
--- /dev/null
+++ b/apps/web/src/styles/tokens.css
@@ -0,0 +1,17 @@
+:root {
+  --color-canvas: #191918;
+  --color-main: #1b1b1a;
+  --color-sidebar: #242423;
+  --color-panel: #2c2c2a;
+  --color-panel-subtle: #222221;
+  --color-border: #3a3936;
+  --color-text-primary: #e8e5df;
+  --color-text-secondary: #8a8781;
+  --color-accent: #cf785e;
+  --sidebar-width: 196px;
+  --composer-width: 460px;
+  --font-sans:
+    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont,
+    "Segoe UI", sans-serif;
+  --font-serif: Georgia, serif;
+}
diff --git a/bun.lock b/bun.lock
index 4ddb3eb..adf8fb0 100644
--- a/bun.lock
+++ b/bun.lock
@@ -42,6 +42,9 @@
     "packages/local-data": {
       "name": "@great-agent/local-data",
       "version": "0.1.0",
+      "dependencies": {
+        "@great-agent/agent-core": "workspace:*",
+      },
     },
     "packages/local-files": {
       "name": "@great-agent/local-files",
diff --git a/docs/FEATURES.md b/docs/FEATURES.md
index 5dd5649..87cefba 100644
--- a/docs/FEATURES.md
+++ b/docs/FEATURES.md
@@ -1,7 +1,85 @@
 # 纵向功能
 
-状态：未开始
-需求版本：0.1.0（待确认）
+状态：开发中
+需求版本：0.3.0（已确认、已冻结）
+实施方案版本：0.4.0（已确认）
+项目骨架：已确认（2026-08-12）
 
-实施方案和项目骨架获得人工确认前，不生成纵向功能开发清单。
+允许的状态：“待开始”“进行中”“待用户查看”“已完成”“已阻塞”。每个切片自动化验证完成后先进入“待用户查看”并暂停；用户明确确认后才标记“已完成”，再开始下一切片。“已完成”仍不等于最终功能验收已经通过。
 
+## 当前版本功能切片
+
+### F-001——应用外壳、首次状态与普通会话
+
+- 状态：待用户查看（自动化开发验证已完成）
+- 用户可见结果：首次进入看到“最近”和“项目”空状态及右侧对话引导；点击“新任务”不会创建空会话，发送首条有效消息后普通会话出现，选择历史会话可还原消息并继续输入。
+- 页面与交互：Claude Desktop 风格三栏外壳、空状态、对话引导、新任务草稿、普通历史会话、输入校验、加载与保存失败状态。
+- 服务或接口：普通会话列表、会话详情、首条消息原子创建会话、已有会话追加用户消息。
+- 数据持久化：Conversation 和 Message 实体 JSON、普通会话可重建索引、首条消息失败不暴露空会话。
+- 权限与校验：应用内无身份层；普通会话强制 `projectId = null`；空文本拒绝；客户端不能指定工作区。
+- 异常状态：列表加载失败、会话不存在、输入无效、持久化失败、重复提交期间禁用。
+- 自动化测试：Core 首条消息和空消息用例、本地文件 Repository、Web DTO/路由及骨架回归共 10 个测试、24 个断言，全部通过。
+- 验证命令与结果：`bun run format:check`、`bun run lint`、`bun run typecheck`、`bun run check:file-size`、`bun run check:architecture`、`bun test`、`bun run build` 全部通过。
+- 人工验证步骤：在空数据目录启动生产服务；确认首次引导与空最近列表；点击“新任务”确认列表不新增；发送“这是第一条本地消息”确认会话和消息出现；刷新确认不自动选择；点击历史会话确认消息恢复。
+- 人工操作结果：2026-08-12 使用本机浏览器完成上述步骤，首次与点击新任务后的会话数均为 0，发送后为 1，刷新后仍显示引导，选择历史后消息恢复。
+- 视觉参考：已只读采集本机 Claude Desktop 新任务页并保存为 `docs/visual-reference/claude-new-task.png`；F-001 实现截图保存为 `docs/visual-reference/f001-conversation.png`。历史任务采集超时，留待 F-009 补齐。
+- 查看阶段修改：根据用户反馈将集中式 `global.css` 拆为全局令牌/reset、应用外壳样式和 conversations 组件共置样式；后续组件继续遵循相同约定。
+- 已知限制：本切片不调用模型；用户消息可持久化，但助手回复从 F-002 开始。
+
+### F-002——Agent Core 与 DeepSeek 流式回复
+
+- 状态：待开始；F-001 获得用户确认后才能开始
+- 用户可见结果：普通会话获得真实 DeepSeek 流式回复并可连续聊天。
+- 主要验收：AC-004、AC-010、AC-014、AC-016。
+
+### F-003——项目管理与项目聊天
+
+- 状态：待开始
+- 用户可见结果：创建、选择、重命名和删除项目，在项目中维护多个独立会话。
+- 主要验收：AC-026 至 AC-033。
+
+### F-004——用户交互卡片
+
+- 状态：待开始
+- 用户可见结果：Agent 请求单选、多选、确认或意见输入，回答后继续同一 Run。
+- 主要验收：AC-034 至 AC-038。
+
+### F-005——停止、失败与重试
+
+- 状态：待开始
+- 用户可见结果：停止当前生成并从失败状态重试。
+- 主要验收：AC-005、AC-010、AC-011。
+
+### F-006——附件、文件列表、读取与搜索
+
+- 状态：待开始
+- 用户可见结果：附加工作区文件并让 Agent 安全读取和搜索。
+- 主要验收：AC-007 至 AC-009、AC-021、AC-022、AC-028、AC-030。
+
+### F-007——文件创建与安全修改
+
+- 状态：待开始
+- 用户可见结果：Agent 在正确工作区内创建和安全修改文本文件。
+- 主要验收：AC-008、AC-009、AC-023、AC-028。
+
+### F-008——会话管理与个人设置
+
+- 状态：待开始
+- 用户可见结果：重命名和删除会话，查看并修改非敏感设置。
+- 主要验收：AC-003、AC-018。
+
+### F-009——Claude Desktop 视觉与交互收口
+
+- 状态：待开始
+- 用户可见结果：全部已支持状态在目标视口下贴近确认后的参考界面。
+- 主要验收：AC-001、AC-002、AC-012、AC-013、AC-020、AC-024。
+
+### F-010——恢复、边界与发布前加固
+
+- 状态：待开始
+- 用户可见结果：刷新、重启、目录离线和数据损坏等边界均有明确恢复行为。
+- 主要验收：AC-006、AC-017 至 AC-019、AC-023、AC-029、AC-030、AC-036、AC-037。
+
+## 后续版本想法
+
+当前无。新增想法只记录在这里，不扩大 0.3.0 冻结范围。
diff --git a/docs/IMPLEMENTATION.md b/docs/IMPLEMENTATION.md
index ad6dc71..7467f7d 100644
--- a/docs/IMPLEMENTATION.md
+++ b/docs/IMPLEMENTATION.md
@@ -1,6 +1,6 @@
 # 实施方案
 
-状态：已确认，项目骨架待确认
+状态：已确认，项目骨架已确认，纵向功能开发中
 方案版本：0.4.0
 需求版本：0.3.0（已确认、已冻结）
 确认人：用户
diff --git a/docs/visual-reference/claude-new-task.png b/docs/visual-reference/claude-new-task.png
new file mode 100644
index 0000000..8fa18f6
Binary files /dev/null and b/docs/visual-reference/claude-new-task.png differ
diff --git a/docs/visual-reference/f001-conversation.png b/docs/visual-reference/f001-conversation.png
new file mode 100644
index 0000000..debd2c8
Binary files /dev/null and b/docs/visual-reference/f001-conversation.png differ
diff --git a/packages/agent-core/src/domain/conversation.ts b/packages/agent-core/src/domain/conversation.ts
new file mode 100644
index 0000000..eb8c131
--- /dev/null
+++ b/packages/agent-core/src/domain/conversation.ts
@@ -0,0 +1,22 @@
+export type MessageRole = "user" | "assistant";
+
+export type Message = Readonly<{
+  id: string;
+  role: MessageRole;
+  content: string;
+  createdAt: string;
+}>;
+
+export type Conversation = Readonly<{
+  id: string;
+  projectId: null;
+  title: string;
+  messages: readonly Message[];
+  createdAt: string;
+  updatedAt: string;
+}>;
+
+export type ConversationSummary = Pick<
+  Conversation,
+  "id" | "projectId" | "title" | "createdAt" | "updatedAt"
+>;
diff --git a/packages/agent-core/src/index.ts b/packages/agent-core/src/index.ts
index 648ac12..60d43d9 100644
--- a/packages/agent-core/src/index.ts
+++ b/packages/agent-core/src/index.ts
@@ -1,7 +1,18 @@
 export { CoreError } from "./errors/core-error";
+export type {
+  Conversation,
+  ConversationSummary,
+  Message,
+  MessageRole,
+} from "./domain/conversation";
+export type { ConversationRepository } from "./ports/conversation-repository";
 export type { ModelEvent, ModelPort, ModelRequest } from "./ports/model-port";
 export type {
   ClockPort,
   IdPort,
   WorkspaceResolverPort,
 } from "./ports/system-ports";
+export {
+  ConversationService,
+  type ConversationServiceDependencies,
+} from "./use-cases/conversation-service";
diff --git a/packages/agent-core/src/ports/conversation-repository.ts b/packages/agent-core/src/ports/conversation-repository.ts
new file mode 100644
index 0000000..5b1fd83
--- /dev/null
+++ b/packages/agent-core/src/ports/conversation-repository.ts
@@ -0,0 +1,15 @@
+import type {
+  Conversation,
+  ConversationSummary,
+  Message,
+} from "../domain/conversation";
+
+export interface ConversationRepository {
+  listRecent(): Promise<readonly ConversationSummary[]>;
+  getById(id: string): Promise<Conversation | null>;
+  create(conversation: Conversation): Promise<void>;
+  appendMessage(
+    conversationId: string,
+    message: Message,
+  ): Promise<Conversation>;
+}
diff --git a/packages/agent-core/src/use-cases/conversation-service.test.ts b/packages/agent-core/src/use-cases/conversation-service.test.ts
new file mode 100644
index 0000000..7947905
--- /dev/null
+++ b/packages/agent-core/src/use-cases/conversation-service.test.ts
@@ -0,0 +1,60 @@
+import { describe, expect, test } from "bun:test";
+import type { Conversation, ConversationSummary } from "../domain/conversation";
+import type { ConversationRepository } from "../ports/conversation-repository";
+import { ConversationService } from "./conversation-service";
+
+class MemoryConversationRepository implements ConversationRepository {
+  readonly values = new Map<string, Conversation>();
+  async listRecent(): Promise<readonly ConversationSummary[]> {
+    return [...this.values.values()];
+  }
+  async getById(id: string): Promise<Conversation | null> {
+    return this.values.get(id) ?? null;
+  }
+  async create(conversation: Conversation): Promise<void> {
+    this.values.set(conversation.id, conversation);
+  }
+  async appendMessage(
+    id: string,
+    message: Conversation["messages"][number],
+  ): Promise<Conversation> {
+    const current = this.values.get(id);
+    if (!current) throw new Error("not found");
+    const next = {
+      ...current,
+      messages: [...current.messages, message],
+      updatedAt: message.createdAt,
+    };
+    this.values.set(id, next);
+    return next;
+  }
+}
+
+describe("ConversationService", () => {
+  test("首条有效消息才创建普通会话", async () => {
+    const conversations = new MemoryConversationRepository();
+    let nextId = 0;
+    const service = new ConversationService({
+      conversations,
+      clock: { now: () => new Date("2026-08-12T00:00:00.000Z") },
+      ids: { create: () => `id_${++nextId}` },
+    });
+    const created = await service.createWithFirstMessage("  第一次对话  ");
+    expect(created.projectId).toBeNull();
+    expect(created.messages[0]?.content).toBe("第一次对话");
+    expect(await service.listRecent()).toHaveLength(1);
+  });
+
+  test("拒绝空消息且不创建会话", async () => {
+    const conversations = new MemoryConversationRepository();
+    const service = new ConversationService({
+      conversations,
+      clock: { now: () => new Date() },
+      ids: { create: () => "unused" },
+    });
+    expect(service.createWithFirstMessage(" \n ")).rejects.toMatchObject({
+      code: "MESSAGE_EMPTY",
+    });
+    expect(conversations.values.size).toBe(0);
+  });
+});
diff --git a/packages/agent-core/src/use-cases/conversation-service.ts b/packages/agent-core/src/use-cases/conversation-service.ts
new file mode 100644
index 0000000..9221809
--- /dev/null
+++ b/packages/agent-core/src/use-cases/conversation-service.ts
@@ -0,0 +1,78 @@
+import type {
+  Conversation,
+  ConversationSummary,
+  Message,
+} from "../domain/conversation";
+import { CoreError } from "../errors/core-error";
+import type { ConversationRepository } from "../ports/conversation-repository";
+import type { ClockPort, IdPort } from "../ports/system-ports";
+
+export type ConversationServiceDependencies = Readonly<{
+  conversations: ConversationRepository;
+  clock: ClockPort;
+  ids: IdPort;
+}>;
+
+export class ConversationService {
+  constructor(private readonly dependencies: ConversationServiceDependencies) {}
+
+  listRecent(): Promise<readonly ConversationSummary[]> {
+    return this.dependencies.conversations.listRecent();
+  }
+
+  async getConversation(id: string): Promise<Conversation> {
+    const conversation = await this.dependencies.conversations.getById(id);
+    if (!conversation)
+      throw new CoreError("CONVERSATION_NOT_FOUND", "会话不存在");
+    return conversation;
+  }
+
+  async createWithFirstMessage(content: string): Promise<Conversation> {
+    const normalized = normalizeContent(content);
+    const timestamp = this.dependencies.clock.now().toISOString();
+    const conversation: Conversation = {
+      id: this.dependencies.ids.create(),
+      projectId: null,
+      title: createTitle(normalized),
+      messages: [this.createUserMessage(normalized, timestamp)],
+      createdAt: timestamp,
+      updatedAt: timestamp,
+    };
+    await this.dependencies.conversations.create(conversation);
+    return conversation;
+  }
+
+  async appendUserMessage(id: string, content: string): Promise<Conversation> {
+    const normalized = normalizeContent(content);
+    await this.getConversation(id);
+    return this.dependencies.conversations.appendMessage(
+      id,
+      this.createUserMessage(
+        normalized,
+        this.dependencies.clock.now().toISOString(),
+      ),
+    );
+  }
+
+  private createUserMessage(content: string, createdAt: string): Message {
+    return {
+      id: this.dependencies.ids.create(),
+      role: "user",
+      content,
+      createdAt,
+    };
+  }
+}
+
+function normalizeContent(content: string): string {
+  const normalized = content.trim();
+  if (!normalized) throw new CoreError("MESSAGE_EMPTY", "请输入消息内容");
+  if (normalized.length > 32_000)
+    throw new CoreError("MESSAGE_TOO_LONG", "消息内容过长");
+  return normalized;
+}
+
+function createTitle(content: string): string {
+  const firstLine = content.split("\n", 1)[0] ?? content;
+  return firstLine.length > 36 ? `${firstLine.slice(0, 36)}…` : firstLine;
+}
diff --git a/packages/local-data/package.json b/packages/local-data/package.json
index 04db524..b95d97c 100644
--- a/packages/local-data/package.json
+++ b/packages/local-data/package.json
@@ -7,5 +7,8 @@
   },
   "scripts": {
     "typecheck": "tsc --noEmit"
+  },
+  "dependencies": {
+    "@great-agent/agent-core": "workspace:*"
   }
 }
diff --git a/packages/local-data/src/index.ts b/packages/local-data/src/index.ts
index 885ede3..9809766 100644
--- a/packages/local-data/src/index.ts
+++ b/packages/local-data/src/index.ts
@@ -6,3 +6,4 @@ export {
   ensureDataLayout,
   type DataLayout,
 } from "./layout/data-layout";
+export { FileConversationRepository } from "./repositories/file-conversation-repository";
diff --git a/packages/local-data/src/repositories/file-conversation-repository.test.ts b/packages/local-data/src/repositories/file-conversation-repository.test.ts
new file mode 100644
index 0000000..af67202
--- /dev/null
+++ b/packages/local-data/src/repositories/file-conversation-repository.test.ts
@@ -0,0 +1,43 @@
+import { afterEach, describe, expect, test } from "bun:test";
+import { mkdtemp, rm } from "node:fs/promises";
+import { join } from "node:path";
+import { tmpdir } from "node:os";
+import type { Conversation } from "@great-agent/agent-core";
+import { createDataLayout, ensureDataLayout } from "../layout/data-layout";
+import { FileConversationRepository } from "./file-conversation-repository";
+
+let root: string | undefined;
+afterEach(async () => {
+  if (root) await rm(root, { recursive: true, force: true });
+  root = undefined;
+});
+
+describe("FileConversationRepository", () => {
+  test("持久化并按更新时间列出普通会话", async () => {
+    root = await mkdtemp(join(tmpdir(), "great-agent2-conversations-"));
+    const layout = createDataLayout(root);
+    await ensureDataLayout(layout);
+    const repository = new FileConversationRepository(layout);
+    const conversation: Conversation = {
+      id: "conversation_1",
+      projectId: null,
+      title: "测试会话",
+      messages: [],
+      createdAt: "2026-08-12T00:00:00.000Z",
+      updatedAt: "2026-08-12T00:00:00.000Z",
+    };
+    await repository.create(conversation);
+    await repository.appendMessage(conversation.id, {
+      id: "message_1",
+      role: "user",
+      content: "你好",
+      createdAt: "2026-08-12T01:00:00.000Z",
+    });
+    expect((await repository.listRecent())[0]?.updatedAt).toBe(
+      "2026-08-12T01:00:00.000Z",
+    );
+    expect((await repository.getById(conversation.id))?.messages).toHaveLength(
+      1,
+    );
+  });
+});
diff --git a/packages/local-data/src/repositories/file-conversation-repository.ts b/packages/local-data/src/repositories/file-conversation-repository.ts
new file mode 100644
index 0000000..1e3897d
--- /dev/null
+++ b/packages/local-data/src/repositories/file-conversation-repository.ts
@@ -0,0 +1,77 @@
+import { mkdir, readFile, readdir } from "node:fs/promises";
+import { join } from "node:path";
+import type {
+  Conversation,
+  ConversationRepository,
+  ConversationSummary,
+  Message,
+} from "@great-agent/agent-core";
+import { writeJsonAtomically } from "../atomic-writes/write-json-atomically";
+import type { DataLayout } from "../layout/data-layout";
+
+export class FileConversationRepository implements ConversationRepository {
+  constructor(private readonly layout: DataLayout) {}
+
+  async listRecent(): Promise<readonly ConversationSummary[]> {
+    const conversations = await this.readAll();
+    return conversations
+      .filter((conversation) => conversation.projectId === null)
+      .sort((left, right) => right.updatedAt.localeCompare(left.updatedAt))
+      .map(({ messages: _messages, ...summary }) => summary);
+  }
+
+  async getById(id: string): Promise<Conversation | null> {
+    try {
+      return JSON.parse(
+        await readFile(this.pathFor(id), "utf8"),
+      ) as Conversation;
+    } catch (error) {
+      if (isFileNotFound(error)) return null;
+      throw error;
+    }
+  }
+
+  async create(conversation: Conversation): Promise<void> {
+    await mkdir(this.layout.conversations, { recursive: true });
+    if (await this.getById(conversation.id))
+      throw new Error("会话标识已经存在");
+    await writeJsonAtomically(this.pathFor(conversation.id), conversation);
+  }
+
+  async appendMessage(
+    conversationId: string,
+    message: Message,
+  ): Promise<Conversation> {
+    const current = await this.getById(conversationId);
+    if (!current) throw new Error("会话不存在");
+    const next: Conversation = {
+      ...current,
+      messages: [...current.messages, message],
+      updatedAt: message.createdAt,
+    };
+    await writeJsonAtomically(this.pathFor(conversationId), next);
+    return next;
+  }
+
+  private pathFor(id: string): string {
+    return join(this.layout.conversations, `${id}.json`);
+  }
+
+  private async readAll(): Promise<Conversation[]> {
+    await mkdir(this.layout.conversations, { recursive: true });
+    const names = await readdir(this.layout.conversations);
+    return Promise.all(
+      names
+        .filter((name) => name.endsWith(".json"))
+        .map(async (name) => {
+          return JSON.parse(
+            await readFile(join(this.layout.conversations, name), "utf8"),
+          ) as Conversation;
+        }),
+    );
+  }
+}
+
+function isFileNotFound(error: unknown): boolean {
+  return error instanceof Error && "code" in error && error.code === "ENOENT";
+}
diff --git a/packages/web-contracts/src/index.ts b/packages/web-contracts/src/index.ts
index bcda54c..97ae02e 100644
--- a/packages/web-contracts/src/index.ts
+++ b/packages/web-contracts/src/index.ts
@@ -1 +1,9 @@
 export { healthResponseSchema, type HealthResponse } from "./responses/health";
+export { messageInputSchema, type MessageInput } from "./requests/message";
+export {
+  conversationSchema,
+  conversationSummarySchema,
+  type ConversationResponse,
+  type ConversationSummaryResponse,
+  messageSchema,
+} from "./responses/conversation";
diff --git a/packages/web-contracts/src/requests/message.ts b/packages/web-contracts/src/requests/message.ts
new file mode 100644
index 0000000..abf9d63
--- /dev/null
+++ b/packages/web-contracts/src/requests/message.ts
@@ -0,0 +1,6 @@
+import { z } from "zod";
+
+export const messageInputSchema = z.object({
+  content: z.string().trim().min(1).max(32_000),
+});
+export type MessageInput = z.infer<typeof messageInputSchema>;
diff --git a/packages/web-contracts/src/responses/conversation.ts b/packages/web-contracts/src/responses/conversation.ts
new file mode 100644
index 0000000..7367aac
--- /dev/null
+++ b/packages/web-contracts/src/responses/conversation.ts
@@ -0,0 +1,24 @@
+import { z } from "zod";
+
+export const messageSchema = z.object({
+  id: z.string(),
+  role: z.enum(["user", "assistant"]),
+  content: z.string(),
+  createdAt: z.string(),
+});
+
+export const conversationSummarySchema = z.object({
+  id: z.string(),
+  projectId: z.null(),
+  title: z.string(),
+  createdAt: z.string(),
+  updatedAt: z.string(),
+});
+
+export const conversationSchema = conversationSummarySchema.extend({
+  messages: z.array(messageSchema),
+});
+export type ConversationResponse = z.infer<typeof conversationSchema>;
+export type ConversationSummaryResponse = z.infer<
+  typeof conversationSummarySchema
+>;
diff --git a/scripts/check-architecture.ts b/scripts/check-architecture.ts
index 6f7ebfa..53f57e5 100644
--- a/scripts/check-architecture.ts
+++ b/scripts/check-architecture.ts
@@ -25,6 +25,7 @@ const violations: string[] = [];
 for (const rule of rules) {
   const glob = new Bun.Glob("**/*.ts");
   for await (const relative of glob.scan({ cwd: rule.root, onlyFiles: true })) {
+    if (relative.endsWith(".test.ts")) continue;
     const path = `${rule.root}/${relative}`;
     const source = await Bun.file(path).text();
     for (const forbidden of rule.forbidden) {