diff --git a/Docs/api-client.md b/Docs/api-client.md
index 08d827b..3ce3b0d 100644
--- a/Docs/api-client.md
+++ b/Docs/api-client.md
@@ -41,11 +41,77 @@
 | 13 | `/api/v1/upload` | POST | JWT(owner/admin) | ✅ | **图片上传**（B1）：multipart/form-data，字段 `file`（raster image，5MB 上限）→ `201 {data:{url,size,mime,name}}`；`url` 为**同源访问地址**（`<host>/api/v1/files/<name>`，可直接作 `chat.image`）。校验：`MaxBytesReader` 防超大 → `DetectContentType` 嗅探（**不信客户端 Content-Type**）→ 白名单 png/jpeg/gif/webp/bmp（**拒 SVG/HTML**）；文件名用 **crypto/rand 128-bit 随机名**（原始文件名丢弃），存 `<dataDir>/uploads/`（0700）。错误码：缺文件 `400 bad_request`、超限 `413 payload_too_large`、非白名单 `415 unsupported_media_type`、未授权 `401/403` |
 | 14 | `/api/v1/files/{name}` | GET | 无需（能力URL） | ✅ | **上传文件访问**（B1）：从 `<dataDir>/uploads/` 读取，同名端口服务。`name` 仅接受「32 位小写 hex + 白名单扩展名」；**路径穿越全形态拒绝**（`..`/`%2f`/`%2e%2e` 等）。返回 `Content-Type`/`Content-Length`/`Cache-Control: private,max-age=86400,immutable`/`X-Content-Type-Options: nosniff`（支持 Range）。**设计取舍**：GET 不鉴权——该 URL 是**128-bit 随机能力地址**（`chat.image`/`<img>` 无法带 Bearer），POST 仍 owner/admin+审计；任何持有该 URL 者都能取文件，勿外泄到他人 |
 
+| 15 | `/api/v1/meta/enums` | GET | JWT（任意角色） | ✅ | **共享枚举权威表**（B4）：`{data:{platforms,moods,modes,unknown}}`，每项 `{id,label}`——`platform`/`mood`/`mode` 的**唯一事实来源**，客户端**不必硬编码**即可拿到稳定映射（来源角标 / 情绪标签不再漂移）。只读、无敏感信息，与 `GET /sessions` 同级（owner/admin/viewer 均可读；无 token 回 `401`）。详见 §1.1 |
+
 > **语音 REST 源（`/api/v1/audio/*`，均 owner-only + 审计）**：原生/移动端用它上传/获取音频，**绕开 WS 4KB 帧限**。
 > - `POST /api/v1/audio/transcribe`：body `{audio:"<base64>", format?:"wav", deviceId?}` → `200 {data:{text}}`。`audio` 为 base64（或 data: URI）；`format` 为编码（`wav`/`mp3`/`ogg`，缺省 `wav`）；空 audio 回 `400`；未注入语音服务 `500 voice_unavailable`、识别失败 `500 stt_failed`。
 > - `POST /api/v1/audio/speech`：body `{text, voice?, format?, instruction?}` → `200` 原始音频字节（`Content-Type: audio/<format>`），**非 JSON envelope**。`voice`/`format` 目前遵循服务端 `VOICE_TTS_VOICE_ID`/`VOICE_TTS_FORMAT` 配置（后续支持按请求覆盖）；`instruction` 为**可选** per-request 情绪/语气指令（如 `"语气开朗俏皮，像女朋友撒娇"`），只对**复刻/设计音色**生效——**系统音色 `longxiaochun_v3` 被服务端忽略，永不发送自由指令**（CosyVoice 系统音色需固定格式）；长度 ≤100 字符（汉字记 2）；未传时回退到服务端 `VOICE_TTS_INSTRUCTION`。空 text 回 `400`；未注入语音服务 `500 voice_unavailable`、合成失败 `500 tts_failed`、静默空音频 `500 tts_empty`。
 > - `POST /api/v1/audio/voice-clone`：body `{url:"<公网参考音频URL>", prefix?:"cyrene"}` → `200 {data:{voiceId}}`。`url` 为**公网可访问的参考音频 URL**（create_voice **只收 `input.url`，不收 base64**），音频要求 10~20s 连续清晰朗读、≤10MB、≥16kHz；`prefix` 为音色名前缀（**≤10 字母/数字**，缺省 `cyrene`）。返回的 `voiceId` 填到 `VOICE_TTS_VOICE_ID` 即可用该复刻音色合成（`target_model` 固定为 `VOICE_TTS_MODEL`，须与合成模型一致）。**URL 不写审计/日志（红线，绝不打日志）**。空 url 回 `400`；未注入语音服务 `500 voice_unavailable`；建音色失败 `500 voice_clone_failed`。**⚠️ 真建音色需主人提供公网参考音频 URL（当前无，断言待提供）；且需北京地域 API Key（CosyVoice 声音复刻仅华北2北京地域）。**
 
+### 1.1 枚举权威表（`GET /api/v1/meta/enums`，B4）
+
+> **背景**：`platform` / `mood` / `mode` 此前只在文档里给示例（`web`/`telegram`/…；`calm`；`normal`），客户端只能自建映射表——来源角标与情绪标签因此会**随客户端漂移**。本端点发布**权威枚举表 + 未知值回落约定**：Web / Android / IM bridge **共用同一份**，客户端不必硬编码。
+
+- **鉴权**：`Authorization: Bearer <JWT>`，**任意已认证角色可读**（`owner`/`admin`/`viewer`），与 `GET /api/v1/sessions` 同级——只读、无敏感信息。无 token / 令牌无效回 `401`。无其它错误码（纯内存投影，无存储、无 501）。
+- **响应**：`200`
+  ```json
+  {"data":{
+    "platforms":[{"id":"web","label":"网页"}, ...],
+    "moods":[{"id":"calm","label":"平静"}, ...],
+    "modes":[{"id":"chat","label":"对话"}, ...],
+    "unknown":"display-raw"
+  }}
+  ```
+  每项固定为 `{"id":"<枚举 id>","label":"<默认中文标签>"}`。`label` 是**默认值**，自带 i18n 的客户端可覆盖显示；`id` 才是必须比对的值。
+- **`unknown`（未知值回落约定，机器可读）**：恒为 `"display-raw"`。语义见下。
+
+**platform（消息来源平台，`{id:label}` 逐值）**
+
+| id | label | 说明 |
+|----|-------|------|
+| `web` | 网页 | Web 主会话来源（`chat_messages.platform` 默认值） |
+| `kook` | KOOK | KOOK 适配器 |
+| `qq-obv11` | QQ | OneBot v11（QQ）适配器 |
+| `weixin-ilink` | 微信 | 微信 iLink 适配器 |
+| `telegram` | Telegram | Telegram Bot API 适配器 |
+| `webhook` | Webhook | 通用 Webhook 适配器 |
+
+**mood（情绪，`{id:label}` 逐值）**
+
+| id | label |
+|----|-------|
+| `calm` | 平静 |
+| `happy` | 开心 |
+| `excited` | 兴奋 |
+| `sad` | 低落 |
+| `angry` | 生气 |
+
+> ⚠️ 情绪状态机**可扩展**（persona 可注册更多状态），因此上表**不是封闭集合**——未知 mood 必须按回落约定原样显示。
+
+**mode（行为/呈现模式，`{id:label}` 逐值）**
+
+| id | label |
+|----|-------|
+| `chat` | 对话 |
+| `code` | 代码 |
+| `home` | 家居 |
+| `work` | 工作 |
+| `docs` | 文档 |
+| `voice` | 语音 |
+| `vision` | 视觉 |
+| `agents` | 智能体 |
+| `settings` | 设置 |
+
+**未知值回落约定（红线）**
+
+- 客户端遇到**不在表中**的取值（`platform` / `mood` / `mode` 任一）：**原样显示该原始字符串**——**不丢弃、不报错、不替换占位符、不猜测**。
+- **服务端新增枚举取值是非破坏性变更**（forward-compatible）：表中新增一项不改变既有字段/端点形状，旧客户端无需升级；**不要**因为读到未知值而清空角标、抛异常或中断渲染。
+- 判定**只比对 `id`**（大小写敏感，契约 id 为小写）；`label` 仅作显示默认值。
+- Web 端镜像实现在 `frontend/web/src/lib/enums.ts`（`labelFor(kind, value)` 对未知值返回原值），权威仍以本端点为准。
+- **反漂移保证（后端）**：后端有测试断言「每个内置适配器的 `Name()` 都在 `platforms` 表内」「`moods` 与 persona 情绪状态机的内置状态一致」「`modes` 与前端 `MODES` 九模式一致」——漏登记即 CI FAIL，客户端拿到的表不会滞后于代码。
+
+> **契约版本 `v0.38`**（新增端点，向后兼容）。
+
 ## 2. REST 端点（管理，`/api/v1/admin/*`）
 
 > 仅供管理面板与授权客户端；RBAC：`owner`/`admin`/`viewer`（viewer 只读、写 403）；**写操作全程审计**。
@@ -261,6 +327,7 @@
 - 语音：上行 `voice_input`（base64 音频或已转写 text），下行 `voice_output`（合成音频 base64 + text）。
 
 ## 5. 变更记录
+- `v0.38`（**B4 客户端共享枚举权威表 + 未知值回落约定**，对客户端**新增一个只读 REST 端点**）：新增 **`GET /api/v1/meta/enums`**（**任意已认证角色可读**，与 `GET /sessions` 同级；无 token `401`）→ `200 {data:{platforms,moods,modes,unknown}}`，每项 `{id,label}`：① **`platforms`**（6）= `web`/`kook`/`qq-obv11`/`weixin-ilink`/`telegram`/`webhook`——即各内置适配器 `Name()` + Web 主会话来源 `web`；② **`moods`**（5）= `calm`/`happy`/`excited`/`sad`/`angry`，与 persona 情绪状态机内置状态一致（该状态机**可扩展**，故非封闭集合）；③ **`modes`**（9）= `chat`/`code`/`home`/`work`/`docs`/`voice`/`vision`/`agents`/`settings`（design/07 §1）；④ **`unknown`** 恒 `"display-raw"` = **未知值回落约定机器可读**：客户端遇不在表中的取值**原样显示原始字符串**（**不丢弃、不报错、不占位符**），**服务端新增取值视为非破坏性变更**（forward-compatible）。**单一事实来源在 Go 侧**（`internal/contract/enums`），并有**反漂移测试**断言适配器 `Name()` / 情绪内置状态 / 前端九模式与三张表一致，漏登记即 CI FAIL。Web 侧镜像 `frontend/web/src/lib/enums.ts`（`labelFor` 未知值返回原值），顶栏/侧栏/消息气泡的「心情」标签已改用它渲染。**向后兼容**：仅新增端点，既有契约形状不变。详见 §1 行 15 与 §1.1。
 - `v0.37`（**D4 未读状态 / 已读游标**，对客户端**新增一个语义字段、一个 REST 端点、一个下行事件**）：① `chat_sessions` 新增 **`read_at INTEGER NOT NULL DEFAULT 0`**（迁移 **0010**，down 可逆；**毫秒 Unix 时间戳**，与 `chat_messages.created_at` **同单位**）。② **语义**：**会话级单一已读游标 + 单 owner 账号**——同一账号所有端共用一个游标，**读一处 = 全端已读**（不做 per-device/per-user 游标，与「同一账号所有浏览器都属于同一 owner」一致）；`createdAt <= readAt` 的消息算已读，未读数 = `createdAt > readAt` 的条数。③ **`GET /api/v1/sessions` 每项新增恒返回的 `unreadCount`**（整数，0 = 无未读）：与 `lastMessage` **同一条 SQL 派生**（关联子查询 `COUNT(*) WHERE session_id = s.id AND created_at > s.read_at`，走已有 `idx_chat_msgs_session_created`，**无 N+1、不新增索引**）。④ **新增 `POST /api/v1/sessions/{id}/read`**（owner/admin，与 `PATCH /sessions/{id}` 同鉴权）：body `{before?}`（可选毫秒；缺省= 现在）→ `200 {data:{sessionId,readAt}}`；`before` 为 0/负数/非数字/body 非对象 → `400`，未知会话（含隔离 `sess-xxx`）→ `404`，未注入 HistoryStore → `501`。**游标只前进不后退**（`read_at = MAX(read_at, before)`），乱序/并发/重试请求幂等安全。⑤ **新增下行事件 `session_read`**：`{type:"session_read", sessionId, data:{readAt}}`，全连接广播 + 客户端按 `sessionId` 过滤，用于同账号其它端清红点；失败路径不广播（§3.9）。⑥ **升级回填**：0010 把既有会话游标回填为「该会话现有最新消息时间」，**升级当天不误报未读**（既有历史全部视为已读）。⑦ `HistoryStore`（网关消费侧契约）新增 `MarkSessionRead(ctx, sessionID, before)`；`SessionMeta` 新增 `UnreadCount`。**向后兼容**：仅新增字段/端点/事件，既有契约形状不变；不消费 `unreadCount`/`session_read` 的客户端行为不变。详见 §1 行 4/8a 与 §3.9。
 - `v0.36`（**A1 流式帧附加会话 / 回合标识**，对客户端**新增两个可选字段、无端点变更**）：结构化流帧 `message.start/delta/end`、`thinking.start/delta/end`、`tool_call.start/delta/end`、`tool_execution.update` 现在带 `sessionId` + `turnId`（**向后兼容**：只新增帧字段，`data` 结构与既有事件形状不变）。`sessionId` 由 loop 在**回合边界**从运行上下文注入（模型适配器在 loop 之下、天然不感知会话，保持零值；loop 外无会话上下文时该字段为空）；`turnId` 由网关**每回合**新生成（`newTurnID`）并经 `loop.WithTurnID` 挂进运行上下文，`runTurn` 是编排层与 legacy 直连路径**唯一**的回合收口点，两路都覆盖——同一会话同时只有一个 in-flight 回合，故同轮内所有帧的 `turnId` 一致。此前这几帧属于 design/16 §4.2 标注的「若知道就带上」缺口（v0.10 起记录）：**多会话并发流式时前端会把别的会话的 delta 接进当前会话气泡**，现在客户端按 `sessionId === activeSessionId` 过滤即可路由到激活会话。`stream_chunk` / `stream_end` 的 `sessionId`/`turnId` 行为不变。详见 §3.1。
 - `v0.35`（**可观测性收尾：后端日志 tail 端点**，对客户端**新增一个 admin 只读端点**）：`GET /api/v1/admin/observability/logs?level=&limit=`（owner/admin）→ `200 {data:[{time,level,source,msg}]}`，**最新在前**。数据源为 logger 新增的**有界环形缓冲**（`internal/logger`，容量 2000，满则丢最旧、并发安全、不阻塞、不改动既有控制台/文件输出），组合根在构建 logger 时挂上、在网关就绪后经 `SetLogBuffer` 注入；缓冲未注入回 `501 not_implemented`（不伪造空 tail）。`time` 为 **RFC3339 UTC（秒精度）**，与 `trace.startedAt`/`audit.when` 一致；`level ∈ debug|info|warn|error`（大小写不敏感）为**最低等级过滤**，空 = 全部，未知值 `400 invalid_level`；`limit` 缺省 `200`、上限 `1000`。`source` 取 `logger.WithSource` 的 `source=`（`Scoped` 记录回落 `module/sub`），无来源为空串。详见 §2「可观测性契约」。
diff --git a/Docs/api-reference.md b/Docs/api-reference.md
index 964a5de..98b6b96 100644
--- a/Docs/api-reference.md
+++ b/Docs/api-reference.md
@@ -68,6 +68,7 @@
 | 9 | PATCH | `/api/v1/sessions/{id}` | owner\|admin | 200 | 会话改名(A4) + 置顶(`pinned`, D5) body `{title?,pinned?}` | M16 |
 | 10 | PATCH | `/api/v1/messages/{id}` | owner\|admin | 200 | 编辑单条消息(D3) body `{content}` | M16 |
 | 11 | DELETE | `/api/v1/messages/{id}` | owner\|admin | 200 | 删除单条消息(D3) | M16 |
+| 12 | GET | `/api/v1/meta/enums` | JWT | 200 | 客户端共享枚举权威表(B4)：`platform`/`mood`/`mode` + `unknown` 回落约定 | M8 |
 
 ### 1.3 管理后台（`/api/v1/admin/*`）
 
@@ -364,6 +365,40 @@ curl -s -X DELETE http://<host>:8080/api/v1/sessions/web:0123abcd... \
 
 ---
 
+### 3.7 GET /api/v1/meta/enums
+- **鉴权**：`Authorize()`（**任意已认证角色**：owner/admin/viewer）——只读、无敏感信息，与 `GET /api/v1/sessions`（§3.2）同级。无 token 回 `401`。
+- **用途**：客户端共享枚举权威表（Android 协同 B4，design/07 §6）。`platform`（消息来源平台）/ `mood`（情绪）/ `mode`（行为·呈现模式）此前只在文档里给示例，客户端各自硬编码映射导致来源角标与情绪标签漂移；本端点把三张表做成**机器可读的单一事实来源**，Web / Android / IM bridge 共用。
+- **响应**：`200`
+  ```json
+  {"data":{
+    "platforms":[{"id":"web","label":"网页"},{"id":"kook","label":"KOOK"},{"id":"qq-obv11","label":"QQ"},{"id":"weixin-ilink","label":"微信"},{"id":"telegram","label":"Telegram"},{"id":"webhook","label":"Webhook"}],
+    "moods":[{"id":"calm","label":"平静"},{"id":"happy","label":"开心"},{"id":"excited","label":"兴奋"},{"id":"sad","label":"低落"},{"id":"angry","label":"生气"}],
+    "modes":[{"id":"chat","label":"对话"},{"id":"code","label":"代码"},{"id":"home","label":"家居"},{"id":"work","label":"工作"},{"id":"docs","label":"文档"},{"id":"voice","label":"语音"},{"id":"vision","label":"视觉"},{"id":"agents","label":"智能体"},{"id":"settings","label":"设置"}],
+    "unknown":"display-raw"
+  }}
+  ```
+- **字段**：
+  | 字段 | 类型 | 说明 |
+  |------|------|------|
+  | `platforms` | `[]{id,label}` | 来源平台：各内置适配器 `Name()`（`kook`/`qq-obv11`/`weixin-ilink`/`telegram`/`webhook`）+ Web 主会话来源 `web`（`history.PlatformWeb`） |
+  | `moods` | `[]{id,label}` | 情绪：`internal/persona/emotion` 内置状态。状态机**可扩展**（persona 可经 `AddTransition` 注册更多状态），此表**非封闭集合** |
+  | `modes` | `[]{id,label}` | 九模式（design/07 §1）；mode 只驱动呈现，不构成能力边界 |
+  | `unknown` | string | 恒 `"display-raw"`：未知值回落约定（机器可读） |
+  | `label` | string | **默认中文标签**，客户端可直接显示、也可按 i18n 覆盖；客户端比对应以 `id` 为准（小写、大小写敏感） |
+- **错误**：仅 `401`（未认证）。无存储依赖，不会 `501`/`500`。
+- **备注**：
+  - **未知值回落约定（红线）**：客户端遇不在表中的取值**原样显示原始字符串**——**不丢弃、不报错、不替换占位符**；**服务端新增取值是非破坏性变更**（forward-compatible），旧客户端无需升级，也不得因未知值清空角标或抛错。
+  - **单一事实来源在 Go 侧**：`internal/contract/enums`（`Platforms()`/`Moods()`/`Modes()`/`UnknownFallback`），网关只做投影（`internal/services/gateway/meta.go`）。
+  - **反漂移**：`internal/contract/enums` 的测试断言三张表与「适配器 `Name()`」「`emotion` 内置状态」「前端 `types.ts` 的 `MODES`」一致；`cmd/cyrene` 另断言表内每个平台都能被渠道工厂构建——漏登记或幽灵条目即 FAIL。
+  - Web 侧镜像：`frontend/web/src/lib/enums.ts`（`labelFor(kind, value)` 未知值返回原值），顶栏 / 侧栏 / 消息气泡的心情标签已改用。
+  - curl：
+    ```bash
+    curl -s http://<host>:8080/api/v1/meta/enums -H "Authorization: Bearer $TOKEN" -H 'X-API-Version: 1'
+    # => {"data":{"platforms":[...],"moods":[...],"modes":[...],"unknown":"display-raw"}}
+    ```
+
+---
+
 ## 4. 管理后台 · 读端点（`owner|admin`）
 
 > 以下端点 `鉴权 = Authorize(owner, admin)`（除特别标注 owner）。所有管理**读**不审计；管理**写**（§5）全程审计（who/what/when/result，见 §4.15）。
diff --git a/cmd/cyrene/enums_factory_test.go b/cmd/cyrene/enums_factory_test.go
new file mode 100644
index 0000000..de61c1e
--- /dev/null
+++ b/cmd/cyrene/enums_factory_test.go
@@ -0,0 +1,46 @@
+package main
+
+// Wiring-level anti-drift test for the shared client enum table (design/07 §6).
+// The enums package test pins the platform table to the adapters' Name() values;
+// this one pins it to the composition root's factory — every platform the table
+// publishes must be one buildAccountAdapter actually knows how to build, so a
+// phantom entry (a platform listed for clients but never wired up) fails here.
+
+import (
+	"io"
+	"testing"
+
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/config"
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/contract/enums"
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/logger"
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/history"
+)
+
+// TestChannelFactoryBuildsEnumeratedPlatforms builds every adapter the published
+// platform table lists (other than the Web main-session source, which is not an
+// adapter) through the real factory and asserts the built adapter's Name()
+// resolves back to that platform. Adapter construction never dials out, so the
+// minimal configs below are enough.
+func TestChannelFactoryBuildsEnumeratedPlatforms(t *testing.T) {
+	t.Parallel()
+	log := logger.New(logger.Options{Out: io.Discard})
+	minimalConfig := map[string]map[string]any{
+		"kook":     {"bot_token": "test"},
+		"telegram": {"bot_token": "test"},
+	}
+
+	for _, p := range enums.Platforms() {
+		if p.ID == history.PlatformWeb {
+			continue
+		}
+		acct := config.ChannelAccount{Config: minimalConfig[p.ID]}
+		built, err := buildAccountAdapter(p.ID, acct, log)
+		if err != nil {
+			t.Errorf("platform %q is published to clients but the factory cannot build it: %v", p.ID, err)
+			continue
+		}
+		if got := barePlatform(built.Name()); got != p.ID {
+			t.Errorf("buildAccountAdapter(%q).Name() = %q, want %q", p.ID, got, p.ID)
+		}
+	}
+}
diff --git a/internal/contract/enums/enums.go b/internal/contract/enums/enums.go
new file mode 100644
index 0000000..86620b7
--- /dev/null
+++ b/internal/contract/enums/enums.go
@@ -0,0 +1,81 @@
+// Package enums is the single Go-side source of truth for the shared client
+// enumerations published at GET /api/v1/meta/enums (Android collaboration B4,
+// design/07 §6). It carries three tables — platform (a message's source
+// platform), mood (a persona's emotion) and mode (the presentation mode a
+// message was produced in) — so every client maps ids to labels from the same
+// place instead of hardcoding its own, which is what made source badges and mood
+// labels drift per client.
+//
+// Adding a value is a non-breaking contract change. A value absent from a table
+// must be rendered raw by the client — never dropped, never an error — and that
+// policy is published alongside the tables (UnknownFallback). The anti-drift
+// tests in this package pin each table to its real source of truth: the platform
+// table to the built-in adapters' Name() values plus the Web main-session source
+// (internal/runtime/history), the mood table to internal/persona/emotion's
+// built-in states, and the mode table to the nine modes design/07 §1 defines
+// (mirrored by frontend/web/src/lib/types.ts MODES).
+package enums
+
+// Item is one enumeration entry: the machine-readable ID a client compares
+// against, plus the default Simplified-Chinese label it may display directly.
+// The label is a default, not a contract: a client with i18n may override it.
+type Item struct {
+	ID    string `json:"id"`
+	Label string `json:"label"`
+}
+
+// UnknownFallback is the machine-readable fallback policy a client applies to a
+// value that is not in the published tables: display the value exactly as
+// received — no label substitution, no drop, no error. It is served in the same
+// response as the tables so a client reads the policy and the data together.
+const UnknownFallback = "display-raw"
+
+// Platforms returns the authoritative message-source platforms: the Web main
+// session plus every built-in IM adapter, keyed by the adapter's Name() value
+// (kook, qq-obv11, weixin-ilink, telegram, webhook).
+//
+// Each call builds a fresh slice, so a caller may sort or otherwise mutate its
+// copy without affecting another — the table itself is never package-level
+// mutable state.
+func Platforms() []Item {
+	return []Item{
+		{ID: "web", Label: "网页"},
+		{ID: "kook", Label: "KOOK"},
+		{ID: "qq-obv11", Label: "QQ"},
+		{ID: "weixin-ilink", Label: "微信"},
+		{ID: "telegram", Label: "Telegram"},
+		{ID: "webhook", Label: "Webhook"},
+	}
+}
+
+// Moods returns the authoritative persona-emotion values, mirroring
+// internal/persona/emotion's built-in states (calm/happy/excited/sad/angry). The
+// emotion state machine is extensible — a persona may register further states via
+// AddTransition — so a client must treat an unlisted mood as display-raw rather
+// than assuming this table is closed.
+func Moods() []Item {
+	return []Item{
+		{ID: "calm", Label: "平静"},
+		{ID: "happy", Label: "开心"},
+		{ID: "excited", Label: "兴奋"},
+		{ID: "sad", Label: "低落"},
+		{ID: "angry", Label: "生气"},
+	}
+}
+
+// Modes returns the authoritative behavior/presentation modes (design/01 §3,
+// design/07 §1). A mode drives how a message is rendered, never what the persona
+// is able to do: it is a presentation dimension, not a capability boundary.
+func Modes() []Item {
+	return []Item{
+		{ID: "chat", Label: "对话"},
+		{ID: "code", Label: "代码"},
+		{ID: "home", Label: "家居"},
+		{ID: "work", Label: "工作"},
+		{ID: "docs", Label: "文档"},
+		{ID: "voice", Label: "语音"},
+		{ID: "vision", Label: "视觉"},
+		{ID: "agents", Label: "智能体"},
+		{ID: "settings", Label: "设置"},
+	}
+}
diff --git a/internal/contract/enums/enums_test.go b/internal/contract/enums/enums_test.go
new file mode 100644
index 0000000..0768c24
--- /dev/null
+++ b/internal/contract/enums/enums_test.go
@@ -0,0 +1,202 @@
+package enums_test
+
+// Anti-drift tests for the shared client enum tables (design/07 §6, requirement
+// 4): each table is pinned to the real code that defines its values, so a value
+// added to (or renamed in) an adapter, the emotion state machine or the frontend
+// mode union without registering it here fails the build rather than silently
+// reaching clients as an unmapped string.
+//
+// The platform test builds the real built-in adapters and asserts the table and
+// their Name() values are the same set — not merely that the table holds some
+// strings. The adapters are constructed with empty configs, which never dials
+// out (Connect does); see cmd/cyrene's factory test for the wiring-level anchor.
+
+import (
+	"errors"
+	"io/fs"
+	"os"
+	"regexp"
+	"slices"
+	"sort"
+	"testing"
+
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/contract/enums"
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/persona/emotion"
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/history"
+	"git.yeij.top/AskaEth/Cyrene_v2/plugins/channels/kook"
+	"git.yeij.top/AskaEth/Cyrene_v2/plugins/channels/qq_obv11"
+	"git.yeij.top/AskaEth/Cyrene_v2/plugins/channels/telegram"
+	"git.yeij.top/AskaEth/Cyrene_v2/plugins/channels/webhook"
+	"git.yeij.top/AskaEth/Cyrene_v2/plugins/channels/weixin_ilink"
+)
+
+// ids maps a table to its id set.
+func ids(items []enums.Item) map[string]bool {
+	out := make(map[string]bool, len(items))
+	for _, it := range items {
+		out[it.ID] = true
+	}
+	return out
+}
+
+// sortedKeys returns the keys of a set in a stable order for diffs.
+func sortedKeys(set map[string]bool) []string {
+	out := make([]string, 0, len(set))
+	for k := range set {
+		out = append(out, k)
+	}
+	sort.Strings(out)
+	return out
+}
+
+// adapterPlatformNames returns the Name() of every built-in IM adapter plus the
+// Web main-session source. It is the authority the platform table mirrors: if an
+// adapter is renamed and the table is not, the two sets diverge and the test
+// fails.
+func adapterPlatformNames(t *testing.T) []string {
+	t.Helper()
+	weixin, err := weixin_ilink.New(weixin_ilink.Config{}, nil, nil)
+	if err != nil {
+		t.Fatalf("build weixin-ilink adapter: %v", err)
+	}
+	return []string{
+		history.PlatformWeb,
+		kook.New(kook.Config{}).Name(),
+		qq_obv11.NewAdapter(qq_obv11.Config{}).Name(),
+		weixin.Name(),
+		telegram.New(telegram.Config{}).Name(),
+		webhook.New().Name(),
+	}
+}
+
+// TestPlatformTableMatchesAdapterNames asserts the published platform table and
+// the adapters the app actually builds are the same set, in both directions: an
+// unregistered adapter (missing entry) and a phantom entry (a platform no
+// adapter provides) both fail.
+func TestPlatformTableMatchesAdapterNames(t *testing.T) {
+	t.Parallel()
+	want := make(map[string]bool)
+	for _, name := range adapterPlatformNames(t) {
+		want[name] = true
+	}
+	got := ids(enums.Platforms())
+	for _, name := range sortedKeys(want) {
+		if !got[name] {
+			t.Errorf("adapter Name() %q is missing from enums.Platforms()", name)
+		}
+	}
+	for _, id := range sortedKeys(got) {
+		if !want[id] {
+			t.Errorf("enums.Platforms() lists %q, which no built-in adapter provides", id)
+		}
+	}
+	if len(want) != len(got) {
+		t.Fatalf("platform count = %d, want %d (table=%v adapters=%v)", len(got), len(want), sortedKeys(got), sortedKeys(want))
+	}
+}
+
+// TestMoodTableMatchesEmotionBuiltins asserts the mood table is exactly the
+// emotion state machine's built-in states, referencing the constants rather than
+// re-typing the strings, and that every state the default transition table
+// mentions is therefore labeled (a transition to an unlabeled state would reach
+// clients as a display-raw string).
+func TestMoodTableMatchesEmotionBuiltins(t *testing.T) {
+	t.Parallel()
+	builtins := []emotion.EmotionState{emotion.Calm, emotion.Happy, emotion.Excited, emotion.Sad, emotion.Angry}
+	want := make(map[string]bool, len(builtins))
+	for _, s := range builtins {
+		want[string(s)] = true
+	}
+	got := ids(enums.Moods())
+	if !slices.Equal(sortedKeys(got), sortedKeys(want)) {
+		t.Fatalf("mood table ids = %v, want the emotion built-ins %v", sortedKeys(got), sortedKeys(want))
+	}
+	for _, entry := range enums.Moods() {
+		if entry.Label == "" {
+			t.Errorf("mood %q has no label", entry.ID)
+		}
+	}
+	for from, tos := range emotion.DefaultTransitions() {
+		if !got[string(from)] {
+			t.Errorf("default transition source %q is not in the mood table", from)
+		}
+		for _, to := range tos {
+			if !got[string(to)] {
+				t.Errorf("default transition target %q is not in the mood table", to)
+			}
+		}
+	}
+}
+
+// TestModeTableMatchesFrontendModes asserts the mode table matches the frontend's
+// Mode union / MODES array (frontend/web/src/lib/types.ts), the only code-level
+// definition of the nine modes. This is the cross-language drift guard: adding a
+// mode on either side without the other fails here.
+func TestModeTableMatchesFrontendModes(t *testing.T) {
+	t.Parallel()
+	const typesPath = "../../../frontend/web/src/lib/types.ts"
+	raw, err := os.ReadFile(typesPath)
+	if err != nil {
+		if errors.Is(err, fs.ErrNotExist) {
+			t.Skipf("%s not present (backend-only checkout)", typesPath)
+		}
+		t.Fatalf("read %s: %v", typesPath, err)
+	}
+	block := regexp.MustCompile(`(?s)export const MODES\s*:[^=]*=\s*\[(.*?)\]`).FindSubmatch(raw)
+	if block == nil {
+		t.Fatalf("MODES array not found in %s", typesPath)
+	}
+	quoted := regexp.MustCompile(`"([^"]+)"`).FindAllStringSubmatch(string(block[1]), -1)
+	frontend := make([]string, 0, len(quoted))
+	for _, m := range quoted {
+		frontend = append(frontend, m[1])
+	}
+	backend := make([]string, 0, len(enums.Modes()))
+	for _, m := range enums.Modes() {
+		backend = append(backend, m.ID)
+	}
+	if !slices.Equal(backend, frontend) {
+		t.Fatalf("mode table = %v, want the frontend MODES %v", backend, frontend)
+	}
+}
+
+// TestTablesAreWellFormed guards the published shape itself: ids are unique and
+// non-empty and every entry carries a default label, so a client can always
+// render something for a known value.
+func TestTablesAreWellFormed(t *testing.T) {
+	t.Parallel()
+	for _, table := range []struct {
+		name  string
+		items []enums.Item
+	}{
+		{name: "platforms", items: enums.Platforms()},
+		{name: "moods", items: enums.Moods()},
+		{name: "modes", items: enums.Modes()},
+	} {
+		if len(table.items) == 0 {
+			t.Fatalf("%s is empty", table.name)
+		}
+		seen := make(map[string]bool, len(table.items))
+		for _, it := range table.items {
+			if it.ID == "" || it.Label == "" {
+				t.Errorf("%s entry %+v must have both id and label", table.name, it)
+			}
+			if seen[it.ID] {
+				t.Errorf("%s id %q is duplicated", table.name, it.ID)
+			}
+			seen[it.ID] = true
+		}
+	}
+}
+
+// TestTablesAreCopies asserts the accessors hand out independent slices, so a
+// caller sorting its copy cannot reorder the authority table for everyone else.
+func TestTablesAreCopies(t *testing.T) {
+	t.Parallel()
+	first := enums.Platforms()
+	first[0] = enums.Item{ID: "mutated", Label: "mutated"}
+	second := enums.Platforms()
+	if second[0].ID != "web" {
+		t.Fatalf("Platforms() shared state: second call starts with %q", second[0].ID)
+	}
+}
diff --git a/internal/services/gateway/meta.go b/internal/services/gateway/meta.go
new file mode 100644
index 0000000..181a411
--- /dev/null
+++ b/internal/services/gateway/meta.go
@@ -0,0 +1,42 @@
+package gateway
+
+import (
+	"net/http"
+
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/contract/enums"
+)
+
+// This file owns the read-only client metadata surface: GET /api/v1/meta/enums,
+// which publishes the authoritative platform/mood/mode tables (Android
+// collaboration B4, design/07 §6). Clients (Web, Android, an IM bridge) read the
+// tables instead of hardcoding their own id → label mapping, so a source badge or
+// a mood label cannot drift per client. The tables themselves live in
+// internal/contract/enums; this handler only serves them, so there is one source
+// of truth rather than a copy per consumer.
+
+// metaEnums is the GET /api/v1/meta/enums payload. `unknown` carries the
+// machine-readable fallback policy (enums.UnknownFallback) so a client reads the
+// tables and the rule for an unlisted value from the same response.
+type metaEnums struct {
+	Platforms []enums.Item `json:"platforms"`
+	Moods     []enums.Item `json:"moods"`
+	Modes     []enums.Item `json:"modes"`
+	Unknown   string       `json:"unknown"`
+}
+
+// handleListEnums serves the shared client enum tables. It is a pure projection
+// of the Go-side authority (no store, no error path) and contains nothing
+// sensitive, so it is gated like GET /api/v1/sessions: any authenticated role may
+// read it.
+//
+// Adding a value to a table is a non-breaking change for existing clients, which
+// must display an unlisted value raw (see enums.UnknownFallback) rather than
+// dropping it or erroring.
+func (s *Server) handleListEnums(w http.ResponseWriter, _ *http.Request) {
+	writeJSON(w, http.StatusOK, metaEnums{
+		Platforms: enums.Platforms(),
+		Moods:     enums.Moods(),
+		Modes:     enums.Modes(),
+		Unknown:   enums.UnknownFallback,
+	})
+}
diff --git a/internal/services/gateway/meta_test.go b/internal/services/gateway/meta_test.go
new file mode 100644
index 0000000..9e76f31
--- /dev/null
+++ b/internal/services/gateway/meta_test.go
@@ -0,0 +1,138 @@
+package gateway
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/auth"
+)
+
+// These tests cover the shared client enum endpoint (Android collaboration B4,
+// design/07 §6): the wire shape of GET /api/v1/meta/enums, the values it
+// publishes, and the fact that it is readable by any authenticated role. They
+// assert the JSON contract with literals rather than by comparing against
+// internal/contract/enums, so the client-facing shape is pinned independently of
+// the Go table (the table's own drift tests live in that package).
+
+// enumEntry is the wire shape of one published enum item.
+type enumEntry struct {
+	ID    string `json:"id"`
+	Label string `json:"label"`
+}
+
+// metaEnumsWire decodes GET /api/v1/meta/enums and asserts the envelope and the
+// per-item shape, returning the ids of each table for value assertions.
+func metaEnumsWire(t *testing.T, ts *httptest.Server, tok string) (platforms, moods, modes []string, unknown string) {
+	t.Helper()
+	resp, body := doReq(t, http.MethodGet, ts.URL+"/api/v1/meta/enums", nil, tok)
+	if resp.StatusCode != http.StatusOK {
+		t.Fatalf("status = %d, want 200 (body=%s)", resp.StatusCode, body)
+	}
+	env := decodeBody(t, body)
+	if len(env) != 1 {
+		t.Fatalf("envelope keys = %v, want only data", env)
+	}
+	var data struct {
+		Platforms []enumEntry `json:"platforms"`
+		Moods     []enumEntry `json:"moods"`
+		Modes     []enumEntry `json:"modes"`
+		Unknown   string      `json:"unknown"`
+	}
+	if err := json.Unmarshal(env["data"], &data); err != nil {
+		t.Fatalf("decode data: %v (body=%s)", err, body)
+	}
+	for _, table := range []struct {
+		name    string
+		entries []enumEntry
+	}{{"platforms", data.Platforms}, {"moods", data.Moods}, {"modes", data.Modes}} {
+		if len(table.entries) == 0 {
+			t.Fatalf("%s is empty (body=%s)", table.name, body)
+		}
+		for _, e := range table.entries {
+			if e.ID == "" || e.Label == "" {
+				t.Errorf("%s entry %+v must carry both id and label", table.name, e)
+			}
+		}
+	}
+	return entryIDs(data.Platforms), entryIDs(data.Moods), entryIDs(data.Modes), data.Unknown
+}
+
+func entryIDs(items []enumEntry) []string {
+	out := make([]string, 0, len(items))
+	for _, it := range items {
+		out = append(out, it.ID)
+	}
+	return out
+}
+
+// TestMetaEnumsShape pins the published contract: the three tables name the real
+// platform/mood/mode values and the response carries the unknown-value fallback
+// policy.
+func TestMetaEnumsShape(t *testing.T) {
+	t.Parallel()
+	_, ts, jwt := buildEnv(t, cfgDefault(), Deps{})
+	tok := signAny(t, jwt, "acct", auth.RoleOwner)
+
+	platforms, moods, modes, unknown := metaEnumsWire(t, ts, tok)
+
+	wantPlatforms := []string{"web", "kook", "qq-obv11", "weixin-ilink", "telegram", "webhook"}
+	if !sameStringSet(platforms, wantPlatforms) {
+		t.Errorf("platforms = %v, want %v", platforms, wantPlatforms)
+	}
+	wantMoods := []string{"calm", "happy", "excited", "sad", "angry"}
+	if !sameStringSet(moods, wantMoods) {
+		t.Errorf("moods = %v, want %v", moods, wantMoods)
+	}
+	wantModes := []string{"chat", "code", "home", "work", "docs", "voice", "vision", "agents", "settings"}
+	if !sameStringSet(modes, wantModes) {
+		t.Errorf("modes = %v, want %v", modes, wantModes)
+	}
+	if unknown != "display-raw" {
+		t.Errorf("unknown = %q, want display-raw", unknown)
+	}
+}
+
+// TestMetaEnumsAnyAuthenticatedRole asserts the endpoint is a read-only,
+// non-sensitive table: every role may read it, and anonymous callers get 401
+// rather than the data.
+func TestMetaEnumsAnyAuthenticatedRole(t *testing.T) {
+	t.Parallel()
+	_, ts, jwt := buildEnv(t, cfgDefault(), Deps{})
+	url := ts.URL + "/api/v1/meta/enums"
+
+	for _, role := range []auth.Role{auth.RoleOwner, auth.RoleAdmin, auth.RoleViewer} {
+		tok := signAny(t, jwt, "acct", role)
+		resp, body := doReq(t, http.MethodGet, url, nil, tok)
+		if resp.StatusCode != http.StatusOK {
+			t.Fatalf("role %s status = %d, want 200 (body=%s)", role, resp.StatusCode, body)
+		}
+	}
+
+	resp, body := doReq(t, http.MethodGet, url, nil, "")
+	if resp.StatusCode != http.StatusUnauthorized {
+		t.Fatalf("anonymous status = %d, want 401 (body=%s)", resp.StatusCode, body)
+	}
+	wantErrorShape(t, body)
+}
+
+// sameStringSet reports whether got and want hold the same values, ignoring order.
+func sameStringSet(got, want []string) bool {
+	if len(got) != len(want) {
+		return false
+	}
+	seen := make(map[string]int, len(got))
+	for _, v := range got {
+		seen[v]++
+	}
+	for _, v := range want {
+		seen[v]--
+	}
+	for _, n := range seen {
+		if n != 0 {
+			return false
+		}
+	}
+	return true
+}
diff --git a/internal/services/gateway/routes.go b/internal/services/gateway/routes.go
index 69edd54..a09847c 100644
--- a/internal/services/gateway/routes.go
+++ b/internal/services/gateway/routes.go
@@ -58,6 +58,12 @@ func (s *Server) registerUserRoutes(
 	mux.Handle("POST /api/v1/chat", writeAuth(http.HandlerFunc(s.handleChat)))
 	mux.Handle("GET /api/v1/sessions", anyAuth(http.HandlerFunc(s.handleListSessions)))
 	mux.Handle("GET /api/v1/personas", anyAuth(http.HandlerFunc(s.handleListPersonas)))
+	// Shared client enum tables (Android collaboration B4, design/07 §6): the
+	// authority every client maps ids to labels from, so a source badge or a mood
+	// label cannot drift per client. A read-only projection of
+	// internal/contract/enums with nothing sensitive in it, so any authenticated
+	// role may read it (same gate as /sessions above).
+	mux.Handle("GET /api/v1/meta/enums", anyAuth(http.HandlerFunc(s.handleListEnums)))
 
 	mux.Handle("POST /api/v1/audio/transcribe", ownerAuth(http.HandlerFunc(s.handleTranscribe)))
 	mux.Handle("POST /api/v1/audio/speech", ownerAuth(http.HandlerFunc(s.handleSpeech)))