diff --git a/CMakeLists.txt b/CMakeLists.txt
index 31dd62d..36c1edd 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,6 +1,19 @@
-cmake_minimum_required(VERSION 4.3)
+cmake_minimum_required(VERSION 3.10)
 project(DataRouter C)
 
 set(CMAKE_C_STANDARD 11)
 
-add_library(DataRouter STATIC library.c)
+add_library(DataRouter STATIC datarouter.c)
+target_include_directories(DataRouter PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
+
+if(BUILD_EXAMPLES OR NOT DEFINED BUILD_EXAMPLES)
+    add_executable(example example.c)
+    target_link_libraries(example DataRouter)
+endif()
+
+if(BUILD_TESTING OR NOT DEFINED BUILD_TESTING)
+    enable_testing()
+    add_executable(test_datarouter tests/test_datarouter.c)
+    target_link_libraries(test_datarouter DataRouter)
+    add_test(NAME datarouter COMMAND test_datarouter)
+endif()
diff --git a/DESIGN.md b/DESIGN.md
new file mode 100644
index 0000000..5785df0
--- /dev/null
+++ b/DESIGN.md
@@ -0,0 +1,512 @@
+# DataRouter 详细设计文档
+
+## 1. 设计目标
+
+轻量级 C 语言数据路由库。核心思想：
+
+- **报文类型（Channel）**：编译期通过宏声明的数据类型（如 `sensor` / `status` / `control`）
+- **端口（Port）**：运行期创建的连接点，绑定一个报文类型 + 一个物理外设发送 handler
+- **路由（Routing）**：将逻辑报文类型连接到实际的物理外设发送函数
+
+```
+应用层  send_sensor(port, data)
+              │
+              ▼
+         库校验端口
+              │
+              ▼
+         调用注册的 handler(data)  ← 用户实现：UART / TCP / CAN / 文件发送
+              │
+              ▼
+         物理外设
+```
+
+### 设计原则
+
+| 原则 | 说明 |
+|------|------|
+| 编译期确定类型 | 所有报文类型在 `datarouter_config.h` 中声明，库自动生成代码 |
+| 运行期绑定外设 | 端口创建后，用户注册具体的发送 handler（函数指针） |
+| 不关心物理外设 | 库不依赖任何外设 API，只调用用户提供的 handler |
+| 零动态内存 | 纯静态数组，无 malloc/free |
+
+---
+
+## 2. 整体架构
+
+### 2.1 模块依赖
+
+```plantuml
+@startuml
+left to right direction
+
+rectangle "用户代码" as User {
+  component "应用逻辑\n调用 datarouter_send_<type>()" as App
+  component "datarouter_config.h\n声明报文类型" as Cfg
+  component "外设 handler\nUART / TCP / CAN / 文件" as Handlers
+  component "接收回调\n处理收到的报文" as Callbacks
+}
+
+database "DataRouter 库" as Lib {
+  component "datarouter.h\n公共 API + 代码生成" as Hdr
+  component "datarouter.c\n端口表 + handler 调用" as Impl
+}
+
+App --> Hdr
+Cfg --> Hdr
+Impl --> Cfg
+Handlers --> Impl : 注册为 send_handler
+Callbacks --> Impl : 实现 on_recv_<type>
+
+@enduml
+```
+
+### 2.2 文件结构
+
+| 文件 | 职责 |
+|------|------|
+| `datarouter_config.h` | 用户在此声明所有报文类型 |
+| `datarouter.h` | 公共 API + X-macro 展开（enum + 发送函数声明 + 回调声明） |
+| `datarouter.c` | 发送函数实现 + handler 调用 + 端口管理 |
+| `example.c` | 使用示例 |
+| `tests/test_datarouter.c` | 31 个单元测试 |
+
+---
+
+## 3. 核心概念
+
+### 3.1 报文类型（Channel）
+
+```plantuml
+@startuml
+object "DATAROUTER_CHANNEL(sensor, \"Sensor data\")" as C1
+object "DATAROUTER_CHANNEL(status, \"Status report\")" as C2
+object "DATAROUTER_CHANNEL(control, \"Control command\")" as C3
+
+note right of C1
+  编译期展开产物：
+  · DATAROUTER_CHANNEL_sensor = 0
+  · int datarouter_send_sensor(port, data, len)
+  · void datarouter_on_recv_sensor(port, data, len)
+  · channel_names[0] = "sensor"
+  · channel_descs[0] = "Sensor data"
+end note
+
+C1 --> C2
+C2 --> C3
+@enduml
+```
+
+### 3.2 端口与 handler
+
+```plantuml
+@startuml
+skinparam objectBorderColor black
+
+object "端口 A" as PA {
+  type = sensor
+  handler = uart_send
+}
+
+object "端口 B" as PB {
+  type = sensor
+  handler = tcp_send
+}
+
+object "端口 C" as PC {
+  type = status
+  handler = uart_send
+}
+
+object "UART发送函数" as UART
+object "TCP发送函数" as TCP
+
+PA --> UART : 注册
+PB --> TCP : 注册
+PC --> UART : 注册
+
+note right of PA
+  同一报文类型 sensor
+  可路由到不同外设
+end note
+
+note right of PC
+  不同报文类型 status
+  可复用同一外设 UART
+end note
+
+@enduml
+```
+
+---
+
+## 4. X-macro 代码生成
+
+### 4.1 展开流程
+
+```plantuml
+@startuml
+
+== datarouter.h: 3 次展开 ==
+
+-> datarouter_config.h: #include 获得 DATAROUTER_CHANNELS
+
+datarouter.h -> "第 1 遍": #define DATAROUTER_CHANNEL(id,desc) DATAROUTER_CHANNEL_##id,
+note right: 生成 enum 通道枚举
+
+datarouter.h -> "第 2 遍": #define DATAROUTER_CHANNEL(id,desc) int datarouter_send_##id(...);
+note right: 生成发送触发函数声明
+
+datarouter.h -> "第 3 遍": #define DATAROUTER_CHANNEL(id,desc) void datarouter_on_recv_##id(...);
+note right: 生成接收回调声明
+
+== datarouter.c: 3 次展开 ==
+
+datarouter.c -> "第 4 遍": #define DATAROUTER_CHANNEL(id,desc) DATAROUTER_WEAK void ...
+note right: 弱符号回调默认空实现
+
+datarouter.c -> "第 5 遍": #define DATAROUTER_CHANNEL(id,desc) int datarouter_send_##id(…) {…}
+note right: 发送函数实现 → 调用handler
+
+datarouter.c -> "第 6 遍": #define DATAROUTER_CHANNEL(id,desc) #id,  → channel_names[]
+datarouter.c -> "第 7 遍": #define DATAROUTER_CHANNEL(id,desc) desc, → channel_descs[]
+
+@enduml
+```
+
+### 4.2 展开示例（3 个通道）
+
+```
+用户配置:
+    DATAROUTER_CHANNEL(sensor,  "Sensor data")
+    DATAROUTER_CHANNEL(status,  "Status report")
+    DATAROUTER_CHANNEL(control, "Control command")
+
+展开产物:
+    enum:   sensor = 0, status = 1, control = 2, CHANNEL_COUNT = 3
+
+    发送:   int datarouter_send_sensor(uint32_t, const void*, size_t);
+            int datarouter_send_status(…);
+            int datarouter_send_control(…);
+
+    回调:   void datarouter_on_recv_sensor(uint32_t, const void*, size_t);
+            void datarouter_on_recv_status(…);
+            void datarouter_on_recv_control(…);
+
+    元数据: names[]  = {"sensor", "status", "control"}
+            descs[]  = {"Sensor data", "Status report", "Control command"}
+```
+
+---
+
+## 5. 数据结构
+
+### 5.1 核心数据类型
+
+```plantuml
+@startuml
+skinparam classAttributeIconSize 0
+
+class "datarouter_channel (enum)" as Chan {
+  + DATAROUTER_CHANNEL_sensor  = 0
+  + DATAROUTER_CHANNEL_status  = 1
+  + DATAROUTER_CHANNEL_control = 2
+  + DATAROUTER_CHANNEL_COUNT   = 3
+}
+
+class "datarouter_send_handler_t" as Handler {
+  + void (*)(uint32_t port_id, const void *data, size_t len)
+}
+
+class "端口表" as Table {
+  - port_entry_t ports[64]
+  - uint8_t initialized
+}
+
+class "port_entry_t" as Entry {
+  - int    type
+  - datarouter_send_handler_t handler
+  - uint8_t in_use
+}
+
+class "发送函数" as Send {
+  + int send_sensor(port, data, len)
+  + int send_status(port, data, len)
+  + int send_control(port, data, len)
+}
+
+class "接收回调" as Recv {
+  + void on_recv_sensor(port, data, len)   ← 用户实现
+  + void on_recv_status(port, data, len)
+  + void on_recv_control(port, data, len)
+}
+
+Entry --> Chan : type ∈ enum
+Entry --> Handler : handler 函数指针
+Table --> Entry : ports[]
+Send --> Table : 校验端口 + 调用 handler
+Recv --> Send : 被用户从外设收数据时调用
+@enduml
+```
+
+### 5.2 `port_entry_t`
+
+```c
+typedef struct {
+    int                       type;     // 报文类型（DATAROUTER_CHANNEL_xxx / -1）
+    datarouter_send_handler_t handler;  // 外设发送函数（NULL 表示未注册）
+    uint8_t                   in_use;   // 1=已分配，0=空闲
+} port_entry_t;
+```
+
+### 5.3 端口表
+
+```c
+#define DATAROUTER_MAX_PORTS 64        // 可由 -D 覆盖
+static port_entry_t ports[64];         // 静态数组，无动态内存
+static uint8_t      initialized;       // init/reset 标志
+```
+
+---
+
+## 6. API 参考
+
+### 6.1 初始化
+
+```c
+void datarouter_init(void);   // 幂等初始化
+void datarouter_reset(void);  // 重置所有状态（测试隔离/热重启）
+```
+
+### 6.2 端口管理
+
+```c
+datarouter_port_t datarouter_port_create(void);    // 返回端口 ID 或 -1
+void              datarouter_port_delete(port);     // 删除端口，ID 可复用
+void              datarouter_port_set_type(port, channel_id);  // 指定报文类型
+int               datarouter_port_get_type(port);   // 获取报文类型，-1 表示无
+void              datarouter_port_set_handler(port, handler);  // 注册外设发送 handler
+datarouter_send_handler_t datarouter_port_get_handler(port);   // 获取 handler
+```
+
+### 6.3 发送触发函数（每通道 1 个，X-macro 生成）
+
+```c
+int datarouter_send_sensor(uint32_t port_id, const void *data, size_t len);
+int datarouter_send_status(uint32_t port_id, const void *data, size_t len);
+int datarouter_send_control(uint32_t port_id, const void *data, size_t len);
+```
+
+返回值：
+| 值 | 含义 |
+|:--:|------|
+| 0 | 成功，handler 已被调用 |
+| -1 | 库未初始化 |
+| -2 | 端口无效或已删除 |
+| -3 | 端口类型与触发的报文类型不匹配 |
+| -4 | 端口未注册外设发送 handler |
+
+### 6.4 接收回调声明（每通道 1 个，用户实现）
+
+```c
+void datarouter_on_recv_sensor(uint32_t port_id, const void *data, size_t len);
+void datarouter_on_recv_status(uint32_t port_id, const void *data, size_t len);
+void datarouter_on_recv_control(uint32_t port_id, const void *data, size_t len);
+```
+
+库提供弱符号默认空实现，用户定义同名函数即可覆盖。
+
+### 6.5 元数据查询
+
+```c
+int         datarouter_channel_count(void);
+const char *datarouter_channel_name(int channel_id);
+const char *datarouter_channel_desc(int channel_id);
+```
+
+---
+
+## 7. 核心流程
+
+### 7.1 发送流程
+
+```plantuml
+@startuml
+actor "应用" as App
+participant "datarouter_send_sensor()" as Send
+participant "端口表" as Table
+participant "handler" as Handler
+participant "外设" as Dev
+
+App -> Send : send_sensor(port=2, data, len)
+
+group 校验
+  Send -> Send : initialized?
+  alt 未初始化
+    Send --> App : return -1
+  end
+
+  Send -> Table : ports[2].in_use?
+  alt 端口无效
+    Send --> App : return -2
+  end
+
+  Send -> Table : ports[2].type == sensor?
+  alt 类型不匹配
+    Send --> App : return -3
+  end
+
+  Send -> Table : ports[2].handler != NULL?
+  alt 无 handler
+    Send --> App : return -4
+  end
+end
+
+Send -> Handler : handler(2, data, len)
+Handler -> Dev : UART_SendData(data, len)
+Handler --> Send : void
+Send --> App : return 0
+@enduml
+```
+
+### 7.2 接收流程
+
+```plantuml
+@startuml
+actor "外设" as Dev
+participant "用户分发代码" as Dispatch
+participant "datarouter_on_recv_sensor()" as Callback
+participant "用户处理逻辑" as Process
+
+Dev -> Dispatch : 收到数据，识别为 sensor 类型
+Dispatch -> Callback : on_recv_sensor(port_id, data, len)
+Callback -> Process : 解析数据、更新状态等
+Process --> Callback : void
+Callback --> Dispatch : void
+@enduml
+```
+
+### 7.3 端口生命周期
+
+```plantuml
+@startuml
+state "空闲\nin_use=0" as Idle
+state "已创建\nin_use=1\ntype=-1\nhandler=NULL" as Created
+state "已配置\nin_use=1\ntype=sensor\nhandler=..." as Config
+
+[*] --> Idle : datarouter_reset()
+
+Idle --> Created : datarouter_port_create()
+
+Created --> Config : set_type + set_handler
+Config --> Config : set_type / set_handler\n可任意切换
+Config --> Created : set_type(-1) / set_handler(NULL)\n清除能力
+
+Created --> Idle : datarouter_port_delete()
+Config --> Idle : datarouter_port_delete()
+Idle --> Created : 复用 ID
+
+@enduml
+```
+
+---
+
+## 8. 路由示例
+
+### 场景：传感器数据同时路由到 UART 和 TCP
+
+```
+应用
+  │
+  ├─ send_sensor(sensor_uart_port, data, len)
+  │    │
+  │    ▼
+  │  handler = uart_send  → UART 外设
+  │
+  └─ send_sensor(sensor_tcp_port, data, len)
+       │
+       ▼
+     handler = tcp_send   → TCP 外设
+```
+
+### 场景：运行时切换路由
+
+```
+端口 sensor_tcp 原 handler = tcp_send
+
+datarouter_port_set_handler(sensor_tcp, file_send);
+
+端口 sensor_tcp 现 handler = file_send  → 改为写入文件
+```
+
+---
+
+## 9. 弱符号机制
+
+```plantuml
+@startuml
+package "libDataRouter.a" {
+  component "弱符号\nvoid on_recv_sensor(...){}" as Weak
+}
+package "用户代码" {
+  component "强符号\nvoid on_recv_sensor(...){...}" as Strong
+}
+package "最终链接产物" {
+  component "使用用户版本" as Result
+}
+Strong --> Result
+Weak ..> Result : 后备
+@enduml
+```
+
+- 库为每个回调提供 `__attribute__((weak))` 空实现
+- 用户定义同名函数自动覆盖
+- 未定义的回调在调用时静默空转
+
+---
+
+## 10. 错误码体系
+
+| 返回值 | 含义 |
+|:------:|------|
+| 0 | 成功 |
+| -1 | 库未初始化 |
+| -2 | 端口无效（越界/未创建/已删除） |
+| -3 | 端口类型不匹配 |
+| -4 | 端口未注册发送 handler |
+
+---
+
+## 11. 配置扩展
+
+### 增加报文类型
+
+编辑 `datarouter_config.h`：
+
+```c
+#define DATAROUTER_CHANNELS \
+    DATAROUTER_CHANNEL(sensor,  "Sensor data")      \
+    DATAROUTER_CHANNEL(status,  "Status report")    \
+    DATAROUTER_CHANNEL(control, "Control command")  \
+    DATAROUTER_CHANNEL(debug,   "Debug message")    /* 新增 */
+```
+
+重新编译后自动生成：枚举、发送函数、回调声明、元数据数组。
+
+### 修改最大端口数
+
+```bash
+cmake -DCMAKE_C_FLAGS="-DDATAROUTER_MAX_PORTS=128" ...
+```
+
+---
+
+## 12. 约束
+
+| 约束 | 说明 |
+|------|------|
+| 报文类型 | 编译期固定，修改需重新编译 |
+| 最大端口数 | 默认 64，可由 `-D` 覆盖 |
+| 线程安全 | 不支持（无锁），多线程需外部加锁 |
+| 弱符号 | GCC/Clang 原生支持 |
+| 内存分配 | 纯静态，无 malloc/free |
diff --git a/TEST_CASES.md b/TEST_CASES.md
new file mode 100644
index 0000000..9b86942
--- /dev/null
+++ b/TEST_CASES.md
@@ -0,0 +1,103 @@
+# DataRouter 单元测试用例文档
+
+## 测试环境
+
+| 项目 | 内容 |
+|------|------|
+| 语言标准 | C11 |
+| 编译器 | GCC 11.4.0 |
+| 测试框架 | 自定义轻量框架（宏 + goto cleanup） |
+| 构建系统 | CMake ≥ 3.10 |
+| 报文类型 | `sensor` / `status` / `control` 三个通道 |
+
+## 运行方式
+
+```bash
+cmake -S . -B build
+cmake --build build
+ctest --test-dir build
+# 或直接运行:
+./build/test_datarouter
+```
+
+## 测试用例列表
+
+### 1. 未初始化（1 个）
+
+| # | 测试名 | 描述 | 步骤 | 预期 |
+|---|--------|------|------|------|
+| 1 | `error_uninit` | 未初始化时不能发送 | ① 不调 init 直接 `send_sensor(0, ...)` | 返回 -1 |
+
+### 2. 端口管理（7 个）
+
+| # | 测试名 | 描述 | 步骤 | 预期 |
+|---|--------|------|------|------|
+| 3 | `port_create_basic` | 基本创建 | ① `datarouter_port_create()` | 返回 ≥ 0 |
+| 4 | `port_create_multiple` | 多端口唯一 ID | ① 连续创建 3 个端口 | ID 互不相同 |
+| 5 | `port_create_reuse` | 删除后 ID 复用 | ① 创建 A ② 删除 A ③ 再创建 | 新 ID == A ID |
+| 6 | `port_delete_invalid` | 删除无效 ID | ① `delete(-1)` ② `delete(9999)` | 不崩溃 |
+| 7 | `port_delete_twice` | 重复删除 | ① 创建 ② 删除 ③ 再次删除 | 不崩溃 |
+| 8 | `port_default_state` | 默认状态 | ① 创建端口 ② `get_type()` ③ `get_handler()` | type == -1, handler == NULL |
+| 9 | `port_create_max` | 满容量边界 | ① 循环创建 64 个 ② 再创建一个 | 64 个成功，第 65 个返回 INVALID |
+
+### 3. 类型与 handler 设置获取（7 个）
+
+| # | 测试名 | 描述 | 步骤 | 预期 |
+|---|--------|------|------|------|
+| 10 | `type_set_get` | 设置并获取类型 | ① `set_type(sensor)` ② `get_type()` | 返回 sensor |
+| 11 | `type_clear` | 清除类型 | ① `set_type(sensor)` ② `set_type(-1)` ③ `get_type()` | 返回 -1 |
+| 12 | `type_switch` | 运行时切换类型 | ① `set_type(sensor)` ② `set_type(status)` ③ `get_type()` | 返回 status |
+| 13 | `type_from_invalid_port` | 无效端口查询类型 | ① `get_type(-1)` ② `get_type(999)` | 均返回 -1 |
+| 14 | `handler_set_get` | 设置并获取 handler | ① `set_handler(f)` ② `get_handler()` | 返回 f |
+| 15 | `handler_clear` | 清除 handler | ① `set_handler(f)` ② `set_handler(NULL)` ③ `get_handler()` | 返回 NULL |
+| 16 | `handler_from_invalid_port` | 无效端口查询 handler | ① `get_handler(-1)` ② `get_handler(999)` | 均返回 NULL |
+
+### 4. 通道元数据查询（4 个）
+
+| # | 测试名 | 描述 | 步骤 | 预期 |
+|---|--------|------|------|------|
+| 17 | `channel_count` | 通道计数 | ① `channel_count()` | 3 |
+| 18 | `channel_names` | 通道名称 | ① 依次 `channel_name(0/1/2)` | "sensor" / "status" / "control" |
+| 19 | `channel_descs` | 通道描述 | ① 依次 `channel_desc(0/1/2)` | "Sensor data" / "Status report" / "Control command" |
+| 20 | `channel_invalid_id` | 无效 ID | ① `channel_name(-1/99)` ② `channel_desc(-1/99)` | 均返回 NULL |
+
+### 5. 发送触发（9 个）
+
+| # | 测试名 | 描述 | 步骤 | 预期 |
+|---|--------|------|------|------|
+| 21 | `send_sensor` | sensor 类型发送 | ① 创建端口 ② set_type(sensor) + set_handler(test) ③ `send_sensor(port, "hello", 5)` | 返回 0；handler 被调用，参数正确 |
+| 22 | `send_status` | status 类型发送 | 同上，用 status 通道 | 返回 0 |
+| 23 | `send_control` | control 类型发送 | 同上，用 control 通道 | 返回 0 |
+| 24 | `send_type_mismatch` | 类型不匹配 | ① set_type(sensor) ② `send_status(port, ...)` | 返回 -3；handler 不被调用 |
+| 25 | `send_no_handler` | 未注册 handler | ① set_type(sensor) ② 不设 handler ③ `send_sensor(port, ...)` | 返回 -4 |
+| 26 | `send_same_type_multiple_ports` | 同类型多端口 | ① 两端口均设 sensor + handler ② 依次发送 | 各调一次 handler |
+| 27 | `send_switch_handler_runtime` | 运行时切换 handler | ① 注册 h1 发送 ② 改注册 h2 发送 | 第一次用 h1，第二次用 h2 |
+| 28 | `send_zero_length` | 零长度数据 | ① 正常端口 ② `send_sensor(port, "x", 0)` | 返回 0；handler 被调用，len=0 |
+| 29 | `send_null_data` | NULL 数据 | ① 正常端口 ② `send_sensor(port, NULL, 0)` | 返回 0；handler 被调用 |
+
+### 6. 接收回调（1 个）
+
+| # | 测试名 | 描述 | 步骤 | 预期 |
+|---|--------|------|------|------|
+| 30 | `recv_callback_user_impl` | 用户实现接收回调 | ① `on_recv_sensor(port, data, len)` ② `on_recv_status(port, data, len)` | sensor 回调触发，status 不触发；再触发 status 回调，sensor 不变 |
+
+### 7. 错误处理（2 个）
+
+| # | 测试名 | 描述 | 步骤 | 预期 |
+|---|--------|------|------|------|
+| 30 | `error_invalid_port` | 无效端口 ID | ① `send_sensor(999, ...)` ② `send_sensor(-1, ...)` | 均返回 -2 |
+| 31 | `error_deleted_port` | 已删除端口 | ① 创建设好类型 + handler ② 删除 ③ `send_sensor(原ID, ...)` | 返回 -2 |
+
+## 覆盖矩阵
+
+| 功能模块 | 用例数 | 主要验证点 |
+|----------|:------:|------------|
+| 未初始化 | 1 | 未 init 调用 send → -1 |
+| 端口生命周期 | 7 | 创建/多创建/ID复用/删除异常/满容量 |
+| 类型与 handler | 7 | set/get/clear/switch/无效端口 |
+| 通道元数据 | 4 | count/names/descs/boundary |
+| 发送触发 | 9 | 三通道/类型不匹配/无handler/多端口/切换handler/零长/NULL |
+| 接收回调 | 1 | 用户实现覆盖弱符号 |
+| 错误处理 | 2 | 无效端口/已删除端口 |
+
+**总计：31 个测试用例**
diff --git a/build/example b/build/example
new file mode 100755
index 0000000..4be9e8b
Binary files /dev/null and b/build/example differ
diff --git a/build/test_datarouter b/build/test_datarouter
new file mode 100755
index 0000000..5cdbb91
Binary files /dev/null and b/build/test_datarouter differ
diff --git a/datarouter.c b/datarouter.c
new file mode 100644
index 0000000..8ce81ee
--- /dev/null
+++ b/datarouter.c
@@ -0,0 +1,188 @@
+/**
+ * @file datarouter.c
+ * @brief 数据路由库 —— 实现
+ *
+ * 端口表：固定大小数组，每个端口存储报文类型 + handler 列表。
+ * 发送触发函数逐一调用端口上注册的全部 handler，实现一对多广播。
+ */
+
+#include "datarouter.h"
+#include <string.h>
+#include <stdio.h>
+
+#if defined(__GNUC__) || defined(__clang__)
+#define DATAROUTER_WEAK __attribute__((weak))
+#else
+#define DATAROUTER_WEAK
+#endif
+
+#ifndef DATAROUTER_MAX_PORTS
+#define DATAROUTER_MAX_PORTS 64
+#endif
+
+/**
+ * @struct port_entry_t
+ * @brief 端口表条目
+ *
+ * @var type     报文类型（DATAROUTER_CHANNEL_xxx / -1）
+ * @var handlers 外设发送 handler 数组
+ * @var count    当前注册的 handler 数量
+ * @var in_use   1=已分配，0=空闲
+ */
+typedef struct {
+    int                       type;
+    datarouter_send_handler_t handlers[DATAROUTER_MAX_HANDLERS_PER_PORT];
+    int                       count;
+    uint8_t                   in_use;
+} port_entry_t;
+
+static port_entry_t ports[DATAROUTER_MAX_PORTS];
+static uint8_t      initialized;
+
+/* ---- 通道元数据（X-macro 展开） ---- */
+
+static const char *channel_names[] = {
+#define DATAROUTER_CHANNEL(id, desc) #id,
+    DATAROUTER_CHANNELS
+#undef DATAROUTER_CHANNEL
+};
+
+static const char *channel_descs[] = {
+#define DATAROUTER_CHANNEL(id, desc) desc,
+    DATAROUTER_CHANNELS
+#undef DATAROUTER_CHANNEL
+};
+
+/* ---- 弱符号接收回调默认实现 ---- */
+
+#define DATAROUTER_CHANNEL(id, desc) \
+    DATAROUTER_WEAK void datarouter_on_recv_##id( \
+        uint32_t port_id, const void *data, size_t len) \
+    { \
+        (void)port_id; (void)data; (void)len; \
+    }
+DATAROUTER_CHANNELS
+#undef DATAROUTER_CHANNEL
+
+/* ---- 发送触发函数实现 ---- */
+
+#define DATAROUTER_CHANNEL(id, desc) \
+    int datarouter_send_##id(uint32_t port_id, const void *data, size_t len) \
+    { \
+        if (!initialized) return -1; \
+        if (port_id >= DATAROUTER_MAX_PORTS || !ports[port_id].in_use) return -2; \
+        if (ports[port_id].type != DATAROUTER_CHANNEL_##id) return -3; \
+        if (ports[port_id].count == 0) return -4; \
+        for (int _i = 0; _i < ports[port_id].count; _i++) \
+            ports[port_id].handlers[_i](port_id, data, len); \
+        return 0; \
+    }
+DATAROUTER_CHANNELS
+#undef DATAROUTER_CHANNEL
+
+/* ---- 端口管理 API ---- */
+
+void datarouter_init(void)
+{
+    if (initialized) return;
+    memset(ports, 0, sizeof(ports));
+    initialized = 1;
+}
+
+void datarouter_reset(void)
+{
+    initialized = 0;
+    memset(ports, 0, sizeof(ports));
+}
+
+datarouter_port_t datarouter_port_create(void)
+{
+    if (!initialized) return DATAROUTER_INVALID_PORT;
+    for (int i = 0; i < DATAROUTER_MAX_PORTS; i++) {
+        if (!ports[i].in_use) {
+            ports[i].in_use  = 1;
+            ports[i].type    = -1;
+            ports[i].count   = 0;
+            return (datarouter_port_t)i;
+        }
+    }
+    return DATAROUTER_INVALID_PORT;
+}
+
+void datarouter_port_delete(datarouter_port_t port)
+{
+    if (!initialized) return;
+    if (port < 0 || port >= DATAROUTER_MAX_PORTS) return;
+    ports[port].in_use = 0;
+}
+
+void datarouter_port_set_type(datarouter_port_t port, int channel_id)
+{
+    if (!initialized) return;
+    if (port < 0 || port >= DATAROUTER_MAX_PORTS || !ports[port].in_use) return;
+    ports[port].type = channel_id;
+}
+
+int datarouter_port_get_type(datarouter_port_t port)
+{
+    if (!initialized) return -1;
+    if (port < 0 || port >= DATAROUTER_MAX_PORTS || !ports[port].in_use) return -1;
+    return ports[port].type;
+}
+
+int datarouter_port_add_handler(datarouter_port_t port, datarouter_send_handler_t handler)
+{
+    if (!initialized) return -1;
+    if (port < 0 || port >= DATAROUTER_MAX_PORTS || !ports[port].in_use) return -1;
+    if (ports[port].count >= DATAROUTER_MAX_HANDLERS_PER_PORT) return -2;
+    for (int i = 0; i < ports[port].count; i++)
+        if (ports[port].handlers[i] == handler) return -3;
+    ports[port].handlers[ports[port].count++] = handler;
+    return 0;
+}
+
+int datarouter_port_remove_handler(datarouter_port_t port, datarouter_send_handler_t handler)
+{
+    if (!initialized) return -1;
+    if (port < 0 || port >= DATAROUTER_MAX_PORTS || !ports[port].in_use) return -1;
+    for (int i = 0; i < ports[port].count; i++) {
+        if (ports[port].handlers[i] == handler) {
+            ports[port].handlers[i] = ports[port].handlers[--ports[port].count];
+            return 0;
+        }
+    }
+    return -2;
+}
+
+void datarouter_port_clear_handlers(datarouter_port_t port)
+{
+    if (!initialized) return;
+    if (port < 0 || port >= DATAROUTER_MAX_PORTS || !ports[port].in_use) return;
+    ports[port].count = 0;
+}
+
+int datarouter_port_handler_count(datarouter_port_t port)
+{
+    if (!initialized) return -1;
+    if (port < 0 || port >= DATAROUTER_MAX_PORTS || !ports[port].in_use) return -1;
+    return ports[port].count;
+}
+
+/* ---- 通道元数据查询 ---- */
+
+int datarouter_channel_count(void)
+{
+    return DATAROUTER_CHANNEL_COUNT;
+}
+
+const char *datarouter_channel_name(int channel_id)
+{
+    if (channel_id < 0 || channel_id >= DATAROUTER_CHANNEL_COUNT) return NULL;
+    return channel_names[channel_id];
+}
+
+const char *datarouter_channel_desc(int channel_id)
+{
+    if (channel_id < 0 || channel_id >= DATAROUTER_CHANNEL_COUNT) return NULL;
+    return channel_descs[channel_id];
+}
diff --git a/datarouter.h b/datarouter.h
new file mode 100644
index 0000000..0e449ef
--- /dev/null
+++ b/datarouter.h
@@ -0,0 +1,162 @@
+/**
+ * @file datarouter.h
+ * @brief 数据路由库 —— 公共接口
+ *
+ * ## 概念
+ *
+ * - **通道 (Channel)**：编译期声明的报文类型（如 sensor / status / control）
+ * - **端口 (Port)**：运行期创建的连接点，绑定一个报文类型和多个外设发送 handler
+ * - **路由**：将报文类型关联到一个或多个物理外设发送函数
+ * - **多外设**：一个端口可注册多个 handler，发送时逐一调用全部 handler
+ *
+ * ## 使用流程
+ *
+ * 1. 在 datarouter_config.h 中声明报文类型
+ * 2. 调用 datarouter_init() 初始化
+ * 3. 通过 datarouter_port_create() 创建端口
+ * 4. 调用 datarouter_port_set_type() 指定端口处理的报文类型
+ * 5. 调用 datarouter_port_add_handler() 注册一个或多个外设发送函数
+ * 6. 调用 datarouter_send_<id>() 触发发送（库逐一调用所有注册的 handler）
+ * 7. 实现 datarouter_on_recv_<id>() 处理从外设收到的报文
+ * 8. datarouter_port_delete() 移除端口
+ *
+ * ## 路由规则
+ *
+ *    datarouter_send_<id>(port, data, len)
+ *      → 校验端口类型
+ *      → for each handler: handler(port, data, len)
+ *      → return 0
+ *
+ * 接收：外设收到数据 → 用户识别报文类型 → 调 datarouter_on_recv_<id>(port, data, len)
+ */
+
+#ifndef DATAROUTER_H
+#define DATAROUTER_H
+
+#include <stdint.h>
+#include <stddef.h>
+
+#include "datarouter_config.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @enum datarouter_channel
+ * @brief 报文类型枚举
+ *
+ * 由 DATAROUTER_CHANNELS 宏列表自动生成。
+ */
+enum datarouter_channel {
+#define DATAROUTER_CHANNEL(id, desc) DATAROUTER_CHANNEL_##id,
+    DATAROUTER_CHANNELS
+#undef DATAROUTER_CHANNEL
+    DATAROUTER_CHANNEL_COUNT
+};
+
+/**
+ * @brief 外设发送 handler 类型
+ *
+ * @param[in] port_id  源端口 ID
+ * @param[in] data     数据缓冲区
+ * @param[in] len      数据长度
+ */
+typedef void (*datarouter_send_handler_t)(uint32_t port_id, const void *data, size_t len);
+
+#ifndef DATAROUTER_MAX_HANDLERS_PER_PORT
+#define DATAROUTER_MAX_HANDLERS_PER_PORT 4
+#endif
+
+/**
+ * @defgroup send_functions 发送触发函数
+ *
+ * 每个报文类型生成一个发送触发函数。
+ * 内部校验端口后，逐一调用端口上注册的所有 handler。
+ * @{
+ */
+
+#define DATAROUTER_CHANNEL(id, desc) \
+    int datarouter_send_##id(uint32_t port_id, const void *data, size_t len);
+DATAROUTER_CHANNELS
+#undef DATAROUTER_CHANNEL
+
+/** @} */
+
+/**
+ * @defgroup recv_callbacks 接收回调声明
+ *
+ * 每个报文类型生成一个接收回调声明。用户实现。
+ * @{
+ */
+
+#define DATAROUTER_CHANNEL(id, desc) \
+    void datarouter_on_recv_##id(uint32_t port_id, const void *data, size_t len);
+DATAROUTER_CHANNELS
+#undef DATAROUTER_CHANNEL
+
+/** @} */
+
+/**
+ * @defgroup port_api 端口管理 API
+ *
+ * 每个端口可注册 N 个外设发送 handler（上限 DATAROUTER_MAX_HANDLERS_PER_PORT）。
+ * 发送时逐一调用全部 handler，实现一对多广播路由。
+ * @{
+ */
+
+typedef int32_t datarouter_port_t;
+#define DATAROUTER_INVALID_PORT ((datarouter_port_t)-1)
+
+void datarouter_init(void);
+void datarouter_reset(void);
+
+datarouter_port_t datarouter_port_create(void);
+void datarouter_port_delete(datarouter_port_t port);
+
+void datarouter_port_set_type(datarouter_port_t port, int channel_id);
+int  datarouter_port_get_type(datarouter_port_t port);
+
+/**
+ * @brief 为端口添加一个外设发送 handler
+ * @param[in] port     端口 ID
+ * @param[in] handler  发送函数指针（不可为 NULL）
+ * @retval 0  成功
+ * @retval -1 端口无效
+ * @retval -2 handler 列表已满
+ * @retval -3 handler 已存在（不重复添加）
+ */
+int datarouter_port_add_handler(datarouter_port_t port, datarouter_send_handler_t handler);
+
+/**
+ * @brief 从端口移除一个外设发送 handler
+ * @param[in] port     端口 ID
+ * @param[in] handler  要移除的函数指针
+ * @retval 0  成功
+ * @retval -1 端口无效
+ * @retval -2 handler 未找到
+ */
+int datarouter_port_remove_handler(datarouter_port_t port, datarouter_send_handler_t handler);
+
+/** @brief 清除端口所有 handler */
+void datarouter_port_clear_handlers(datarouter_port_t port);
+
+/** @brief 获取端口当前 handler 数量 @return handler 数量，-1 表示端口无效 */
+int datarouter_port_handler_count(datarouter_port_t port);
+
+/** @} */
+
+/**
+ * @defgroup introspection 报文类型元数据查询
+ * @{
+ */
+int         datarouter_channel_count(void);
+const char *datarouter_channel_name(int channel_id);
+const char *datarouter_channel_desc(int channel_id);
+/** @} */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* DATAROUTER_H */
\ No newline at end of file
diff --git a/datarouter_config.h b/datarouter_config.h
new file mode 100644
index 0000000..26b0c3c
--- /dev/null
+++ b/datarouter_config.h
@@ -0,0 +1,34 @@
+/**
+ * @file datarouter_config.h
+ * @brief 数据报文类型配置
+ *
+ * 用户在此文件中定义所有报文类型（通道）。
+ * 每个报文类型通过 DATAROUTER_CHANNEL(id, desc) 宏声明，
+ * 库在编译期据此自动生成：
+ *   - 通道枚举值 DATAROUTER_CHANNEL_<id>
+ *   - 发送触发函数 datarouter_send_<id>(port, data, len)
+ *   - 接收回调声明 datarouter_on_recv_<id>(port, data, len)
+ */
+
+#ifndef DATAROUTER_CONFIG_H
+#define DATAROUTER_CONFIG_H
+
+/**
+ * @def DATAROUTER_CHANNELS
+ * @brief 报文类型列表宏
+ *
+ * 每行格式：DATAROUTER_CHANNEL(标识符, "描述文字")
+ * 用户按需增删改。每个标识符对应一种报文类型。
+ *
+ * @code
+ * #define DATAROUTER_CHANNELS \
+ *     DATAROUTER_CHANNEL(sensor,  "Sensor data") \
+ *     DATAROUTER_CHANNEL(control, "Control command")
+ * @endcode
+ */
+#define DATAROUTER_CHANNELS \
+    DATAROUTER_CHANNEL(sensor,  "Sensor data")    \
+    DATAROUTER_CHANNEL(status,  "Status report")  \
+    DATAROUTER_CHANNEL(control, "Control command")
+
+#endif /* DATAROUTER_CONFIG_H */
\ No newline at end of file
diff --git a/example.c b/example.c
new file mode 100644
index 0000000..d5b4f46
--- /dev/null
+++ b/example.c
@@ -0,0 +1,105 @@
+/**
+ * @file example.c
+ * @brief 数据路由库使用示例
+ *
+ * 展示：
+ *   1. 编译期声明报文类型 → 自动生成发送触发函数和接收回调声明
+ *   2. 创建端口、设置报文类型
+ *   3. 为一个端口注册多个外设 handler（一对多广播路由）
+ *   4. 运行时增删 handler，切换路由
+ *   5. 实现接收回调处理外设收到的数据
+ */
+
+#include "datarouter.h"
+#include <stdio.h>
+#include <string.h>
+
+/* ---- 外设发送 handler 实现 ---- */
+
+static void uart_send(uint32_t port_id, const void *data, size_t len)
+{
+    printf("[UART] port %u: %.*s\n", port_id, (int)len, (const char *)data);
+}
+
+static void tcp_send(uint32_t port_id, const void *data, size_t len)
+{
+    printf("[TCP]  port %u: %.*s\n", port_id, (int)len, (const char *)data);
+}
+
+static void file_send(uint32_t port_id, const void *data, size_t len)
+{
+    printf("[FILE] port %u: %.*s\n", port_id, (int)len, (const char *)data);
+}
+
+static void can_send(uint32_t port_id, const void *data, size_t len)
+{
+    printf("[CAN]  port %u: %.*s\n", port_id, (int)len, (const char *)data);
+}
+
+/* ---- 接收回调实现 ---- */
+
+void datarouter_on_recv_sensor(uint32_t port_id, const void *data, size_t len)
+{
+    printf("[RX:sensor] port %u: %.*s\n", port_id, (int)len, (const char *)data);
+}
+
+void datarouter_on_recv_status(uint32_t port_id, const void *data, size_t len)
+{
+    printf("[RX:status] port %u: %.*s\n", port_id, (int)len, (const char *)data);
+}
+
+/* ---- main ---- */
+
+int main(void)
+{
+    datarouter_init();
+
+    printf("Channels:\n");
+    for (int i = 0; i < datarouter_channel_count(); i++)
+        printf("  [%d] %s - %s\n", i,
+               datarouter_channel_name(i),
+               datarouter_channel_desc(i));
+
+    /*
+     * 创建一个 sensor 端口，注册多个 handler。
+     * 一次 send_sensor() 调用同时路由到 UART + TCP + CAN。
+     */
+    datarouter_port_t sensor_port = datarouter_port_create();
+    datarouter_port_set_type(sensor_port, DATAROUTER_CHANNEL_sensor);
+    datarouter_port_add_handler(sensor_port, uart_send);
+    datarouter_port_add_handler(sensor_port, tcp_send);
+    datarouter_port_add_handler(sensor_port, can_send);
+
+    printf("\n--- send sensor (UART + TCP + CAN) ---\n");
+    datarouter_send_sensor(sensor_port, "temperature:25.3", 16);
+
+    /*
+     * 运行时移除 TCP handler，只剩 UART + CAN。
+     */
+    printf("\n--- remove TCP, keep UART + CAN ---\n");
+    datarouter_port_remove_handler(sensor_port, tcp_send);
+    datarouter_send_sensor(sensor_port, "temperature:26.1", 16);
+
+    /*
+     * 运行时再添加 FILE handler。
+     */
+    printf("\n--- add FILE back, now UART + CAN + FILE ---\n");
+    datarouter_port_add_handler(sensor_port, file_send);
+    datarouter_send_sensor(sensor_port, "temperature:27.0", 16);
+
+    /*
+     * 清除所有 handler，不再输出到任何外设。
+     */
+    printf("\n--- clear all handlers, nothing sent ---\n");
+    datarouter_port_clear_handlers(sensor_port);
+    int ret = datarouter_send_sensor(sensor_port, "lost", 4);
+    printf("send_sensor after clear returned %d\n", ret);
+
+    /* ---- 接收 ---- */
+    printf("\n--- simulate peripheral receive ---\n");
+    datarouter_on_recv_sensor(0, "temperature:24.8", 16);
+    datarouter_on_recv_status(1, "status:ERROR", 12);
+
+    datarouter_port_delete(sensor_port);
+    return 0;
+}
diff --git a/library.c b/library.c
deleted file mode 100644
index f431745..0000000
--- a/library.c
+++ /dev/null
@@ -1,7 +0,0 @@
-#include "library.h"
-
-#include <stdio.h>
-
-void hello(void) {
-   printf("Hello, World!\n");
-}
diff --git a/library.h b/library.h
deleted file mode 100644
index f16761c..0000000
--- a/library.h
+++ /dev/null
@@ -1,6 +0,0 @@
-#ifndef DATAROUTER_LIBRARY_H
-#define DATAROUTER_LIBRARY_H
-
-void hello(void);
-
-#endif // DATAROUTER_LIBRARY_H
diff --git a/tests/test_datarouter.c b/tests/test_datarouter.c
new file mode 100644
index 0000000..43eef52
--- /dev/null
+++ b/tests/test_datarouter.c
@@ -0,0 +1,511 @@
+/**
+ * @file test_datarouter.c
+ * @brief 数据路由库单元测试
+ *
+ * 覆盖：
+ *   - 端口管理（创建/删除/复用/边界）
+ *   - 端口类型与多 handler 增删查
+ *   - 通道元数据查询
+ *   - 一对多广播发送（多 handler 逐一调用）
+ *   - 运行时增删 handler 改变路由
+ *   - 接收回调
+ *   - 错误处理
+ */
+
+#include "datarouter.h"
+#include <stdio.h>
+#include <string.h>
+
+/* ================================================================
+ *  测试框架
+ * ================================================================ */
+
+static int  _total_run, _total_pass, _total_fail;
+static int  _err;
+static const char *_cur_name;
+
+#define FIXTURE_MAX 16
+typedef struct {
+    datarouter_port_t ports[FIXTURE_MAX];
+    int count;
+} fixture_t;
+
+#define FIXTURE_INIT(f)     memset((f), 0, sizeof(*(f)))
+#define FIXTURE_PUSH(f, p)  do { if ((f)->count < FIXTURE_MAX) (f)->ports[(f)->count++] = (p); } while (0)
+#define FIXTURE_CLEAN(f)    do { for (int _i = 0; _i < (f)->count; _i++) datarouter_port_delete((f)->ports[_i]); } while (0)
+#define FIXTURE_CREATE(f)   ({ datarouter_port_t _p = datarouter_port_create(); FIXTURE_PUSH(f, _p); _p; })
+
+#define TEST_START(name)                                            \
+    static void test_##name(void)                                   \
+    {                                                               \
+        fixture_t _fix;                                             \
+        FIXTURE_INIT(&_fix);                                        \
+        _cur_name = #name;                                          \
+        _err = 0;
+
+#define TEST_END()                                                  \
+cleanup:                                                            \
+        FIXTURE_CLEAN(&_fix);                                       \
+        if (_err) { _total_fail++; printf("  FAIL %s\n", _cur_name); } \
+        else      { _total_pass++; printf("  PASS %s\n", _cur_name); } \
+        _total_run++;                                               \
+    }
+
+#define CHECK(cond, ...) do {                                       \
+        if (!(cond)) {                                              \
+            printf("  %s [line %d]: ", _cur_name, __LINE__);        \
+            printf(__VA_ARGS__);                                    \
+            printf("\n");                                           \
+            _err = 1;                                               \
+            goto cleanup;                                           \
+        }                                                           \
+    } while (0)
+
+/* ================================================================
+ *  测试用 handler
+ * ================================================================ */
+
+static int  _h_cnt;
+static int  _h_total;
+static int  _h_ids[16];
+static void _h(uint32_t p, const void *d, size_t l)
+{
+    (void)d; (void)l;
+    if (_h_cnt < 16) _h_ids[_h_cnt] = (int)p;
+    _h_cnt++;
+    _h_total++;
+}
+
+static void _h_a(uint32_t p, const void *d, size_t l) { (void)p; (void)d; (void)l; _h_cnt++; }
+static void _h_b(uint32_t p, const void *d, size_t l) { (void)p; (void)d; (void)l; _h_cnt++; }
+static void _h_c(uint32_t p, const void *d, size_t l) { (void)p; (void)d; (void)l; _h_cnt++; }
+static void _h_d(uint32_t p, const void *d, size_t l) { (void)p; (void)d; (void)l; _h_cnt++; }
+
+static void reset_hstate(void)
+{
+    _h_cnt = _h_total = 0;
+    memset(_h_ids, 0, sizeof(_h_ids));
+}
+
+/* ================================================================
+ *  1. 未初始化
+ * ================================================================ */
+
+TEST_START(error_uninit)
+    int ret = datarouter_send_sensor(0, "d", 1);
+    CHECK(ret == -1, "expected -1, got %d", ret);
+TEST_END()
+
+/* ================================================================
+ *  2. 端口管理
+ * ================================================================ */
+
+TEST_START(port_create_basic)
+    datarouter_port_t p = FIXTURE_CREATE(&_fix);
+    CHECK(p >= 0, "create returned %d", p);
+TEST_END()
+
+TEST_START(port_create_multiple)
+    datarouter_port_t p1 = FIXTURE_CREATE(&_fix);
+    datarouter_port_t p2 = FIXTURE_CREATE(&_fix);
+    datarouter_port_t p3 = FIXTURE_CREATE(&_fix);
+    CHECK(p1 >= 0 && p2 >= 0 && p3 >= 0, "some invalid");
+    CHECK(p1 != p2 && p2 != p3, "IDs should be unique");
+TEST_END()
+
+TEST_START(port_create_reuse)
+    datarouter_port_t p1 = FIXTURE_CREATE(&_fix);
+    datarouter_port_delete(p1);
+    datarouter_port_t p2 = FIXTURE_CREATE(&_fix);
+    CHECK(p1 == p2, "expected reuse ID %d, got %d", p1, p2);
+TEST_END()
+
+TEST_START(port_delete_invalid)
+    datarouter_port_delete(-1);
+    datarouter_port_delete(9999);
+TEST_END()
+
+TEST_START(port_delete_twice)
+    datarouter_port_t p = FIXTURE_CREATE(&_fix);
+    datarouter_port_delete(p);
+    datarouter_port_delete(p);
+    _fix.count--;
+TEST_END()
+
+TEST_START(port_default_state)
+    datarouter_port_t p = FIXTURE_CREATE(&_fix);
+    CHECK(datarouter_port_get_type(p) == -1, "type should be -1");
+    CHECK(datarouter_port_handler_count(p) == 0, "handler count should be 0");
+TEST_END()
+
+TEST_START(port_create_max)
+    int created = 0;
+    for (int i = 0; i < 64; i++) {
+        datarouter_port_t p = datarouter_port_create();
+        if (p == DATAROUTER_INVALID_PORT) break;
+        FIXTURE_PUSH(&_fix, p);
+        created++;
+    }
+    CHECK(created >= 64, "expected 64, got %d", created);
+    CHECK(datarouter_port_create() == DATAROUTER_INVALID_PORT,
+          "expected INVALID after exhaustion");
+TEST_END()
+
+/* ================================================================
+ *  3. 类型
+ * ================================================================ */
+
+TEST_START(type_set_get)
+    datarouter_port_t p = FIXTURE_CREATE(&_fix);
+    datarouter_port_set_type(p, DATAROUTER_CHANNEL_sensor);
+    CHECK(datarouter_port_get_type(p) == DATAROUTER_CHANNEL_sensor, "type mismatch");
+TEST_END()
+
+TEST_START(type_clear)
+    datarouter_port_t p = FIXTURE_CREATE(&_fix);
+    datarouter_port_set_type(p, DATAROUTER_CHANNEL_sensor);
+    datarouter_port_set_type(p, -1);
+    CHECK(datarouter_port_get_type(p) == -1, "should be -1");
+TEST_END()
+
+TEST_START(type_switch)
+    datarouter_port_t p = FIXTURE_CREATE(&_fix);
+    datarouter_port_set_type(p, DATAROUTER_CHANNEL_sensor);
+    datarouter_port_set_type(p, DATAROUTER_CHANNEL_status);
+    CHECK(datarouter_port_get_type(p) == DATAROUTER_CHANNEL_status, "should be status");
+TEST_END()
+
+TEST_START(type_from_invalid)
+    CHECK(datarouter_port_get_type(-1) == -1, NULL);
+    CHECK(datarouter_port_get_type(999) == -1, NULL);
+TEST_END()
+
+/* ================================================================
+ *  4. 多 handler 增删查
+ * ================================================================ */
+
+TEST_START(handler_add_one)
+    datarouter_port_t p = FIXTURE_CREATE(&_fix);
+    CHECK(datarouter_port_add_handler(p, _h) == 0, "add failed");
+    CHECK(datarouter_port_handler_count(p) == 1, "count=%d", datarouter_port_handler_count(p));
+TEST_END()
+
+TEST_START(handler_add_multiple)
+    datarouter_port_t p = FIXTURE_CREATE(&_fix);
+    CHECK(datarouter_port_add_handler(p, _h_a) == 0, "add a");
+    CHECK(datarouter_port_add_handler(p, _h_b) == 0, "add b");
+    CHECK(datarouter_port_add_handler(p, _h_c) == 0, "add c");
+    CHECK(datarouter_port_handler_count(p) == 3, "count=%d", datarouter_port_handler_count(p));
+TEST_END()
+
+TEST_START(handler_add_duplicate)
+    datarouter_port_t p = FIXTURE_CREATE(&_fix);
+    CHECK(datarouter_port_add_handler(p, _h) == 0, "first add");
+    CHECK(datarouter_port_add_handler(p, _h) == -3, "duplicate should return -3");
+TEST_END()
+
+TEST_START(handler_add_max)
+    datarouter_port_t p = FIXTURE_CREATE(&_fix);
+    CHECK(datarouter_port_add_handler(p, _h_a) == 0, "add a");
+    CHECK(datarouter_port_add_handler(p, _h_b) == 0, "add b");
+    CHECK(datarouter_port_add_handler(p, _h_c) == 0, "add c");
+    CHECK(datarouter_port_add_handler(p, _h_d) == 0, "add d");
+    CHECK(datarouter_port_handler_count(p) == DATAROUTER_MAX_HANDLERS_PER_PORT,
+          "count=%d", datarouter_port_handler_count(p));
+    /* 第 5 个应返回 -2（已满） */
+    CHECK(datarouter_port_add_handler(p, _h) == -2,
+          "expected -2 (full), got %d", datarouter_port_add_handler(p, _h));
+TEST_END()
+
+TEST_START(handler_remove)
+    datarouter_port_t p = FIXTURE_CREATE(&_fix);
+    datarouter_port_add_handler(p, _h_a);
+    datarouter_port_add_handler(p, _h_b);
+    datarouter_port_add_handler(p, _h_c);
+    CHECK(datarouter_port_remove_handler(p, _h_b) == 0, "remove b");
+    CHECK(datarouter_port_handler_count(p) == 2, "count should be 2, got %d", datarouter_port_handler_count(p));
+TEST_END()
+
+TEST_START(handler_remove_not_found)
+    datarouter_port_t p = FIXTURE_CREATE(&_fix);
+    CHECK(datarouter_port_remove_handler(p, _h) == -2, "expected -2");
+TEST_END()
+
+TEST_START(handler_clear)
+    datarouter_port_t p = FIXTURE_CREATE(&_fix);
+    datarouter_port_add_handler(p, _h_a);
+    datarouter_port_add_handler(p, _h_b);
+    datarouter_port_clear_handlers(p);
+    CHECK(datarouter_port_handler_count(p) == 0, "count should be 0");
+TEST_END()
+
+TEST_START(handler_from_invalid)
+    CHECK(datarouter_port_handler_count(-1) == -1, NULL);
+    CHECK(datarouter_port_handler_count(999) == -1, NULL);
+    CHECK(datarouter_port_add_handler(-1, _h) == -1, NULL);
+    CHECK(datarouter_port_remove_handler(999, _h) == -1, NULL);
+TEST_END()
+
+/* ================================================================
+ *  5. 通道元数据
+ * ================================================================ */
+
+TEST_START(channel_count)
+    CHECK(datarouter_channel_count() == 3, "expected 3");
+TEST_END()
+
+TEST_START(channel_names)
+    CHECK(strcmp(datarouter_channel_name(0), "sensor") == 0, NULL);
+    CHECK(strcmp(datarouter_channel_name(1), "status") == 0, NULL);
+    CHECK(strcmp(datarouter_channel_name(2), "control") == 0, NULL);
+TEST_END()
+
+TEST_START(channel_descs)
+    CHECK(strcmp(datarouter_channel_desc(0), "Sensor data") == 0, NULL);
+    CHECK(strcmp(datarouter_channel_desc(1), "Status report") == 0, NULL);
+    CHECK(strcmp(datarouter_channel_desc(2), "Control command") == 0, NULL);
+TEST_END()
+
+TEST_START(channel_invalid_id)
+    CHECK(datarouter_channel_name(-1) == NULL, NULL);
+    CHECK(datarouter_channel_name(99) == NULL, NULL);
+    CHECK(datarouter_channel_desc(-1) == NULL, NULL);
+    CHECK(datarouter_channel_desc(99) == NULL, NULL);
+TEST_END()
+
+/* ================================================================
+ *  6. 发送 — 一对多广播
+ * ================================================================ */
+
+TEST_START(send_one_handler)
+    datarouter_port_t p = FIXTURE_CREATE(&_fix);
+    datarouter_port_set_type(p, DATAROUTER_CHANNEL_sensor);
+    datarouter_port_add_handler(p, _h);
+
+    reset_hstate();
+    CHECK(datarouter_send_sensor(p, "d", 1) == 0, "send failed");
+    CHECK(_h_cnt == 1, "handler called %d times", _h_cnt);
+TEST_END()
+
+TEST_START(send_multi_handlers)
+    datarouter_port_t p = FIXTURE_CREATE(&_fix);
+    datarouter_port_set_type(p, DATAROUTER_CHANNEL_sensor);
+    datarouter_port_add_handler(p, _h_a);
+    datarouter_port_add_handler(p, _h_b);
+    datarouter_port_add_handler(p, _h_c);
+
+    reset_hstate();
+    CHECK(datarouter_send_sensor(p, "d", 1) == 0, "send failed");
+    CHECK(_h_cnt == 3, "expected 3 handler calls, got %d", _h_cnt);
+TEST_END()
+
+TEST_START(send_type_mismatch)
+    datarouter_port_t p = FIXTURE_CREATE(&_fix);
+    datarouter_port_set_type(p, DATAROUTER_CHANNEL_sensor);
+    datarouter_port_add_handler(p, _h);
+
+    reset_hstate();
+    CHECK(datarouter_send_status(p, "d", 1) == -3, "expected -3");
+    CHECK(_h_cnt == 0, "handler should not fire");
+TEST_END()
+
+TEST_START(send_no_handler)
+    datarouter_port_t p = FIXTURE_CREATE(&_fix);
+    datarouter_port_set_type(p, DATAROUTER_CHANNEL_sensor);
+
+    reset_hstate();
+    CHECK(datarouter_send_sensor(p, "d", 1) == -4, "expected -4");
+TEST_END()
+
+TEST_START(send_three_channels)
+    /* 三个通道各一个端口 */
+    datarouter_port_t p1 = FIXTURE_CREATE(&_fix);
+    datarouter_port_t p2 = FIXTURE_CREATE(&_fix);
+    datarouter_port_t p3 = FIXTURE_CREATE(&_fix);
+    datarouter_port_set_type(p1, DATAROUTER_CHANNEL_sensor);
+    datarouter_port_set_type(p2, DATAROUTER_CHANNEL_status);
+    datarouter_port_set_type(p3, DATAROUTER_CHANNEL_control);
+    datarouter_port_add_handler(p1, _h);
+    datarouter_port_add_handler(p2, _h);
+    datarouter_port_add_handler(p3, _h);
+
+    reset_hstate();
+    CHECK(datarouter_send_sensor(p1, "a", 1) == 0, NULL);
+    CHECK(datarouter_send_status(p2, "b", 1) == 0, NULL);
+    CHECK(datarouter_send_control(p3, "c", 1) == 0, NULL);
+    CHECK(_h_cnt == 3, "expected 3 total calls, got %d", _h_cnt);
+TEST_END()
+
+/* ================================================================
+ *  7. 发送 — 运行时增删 handler
+ * ================================================================ */
+
+TEST_START(send_remove_handler)
+    datarouter_port_t p = FIXTURE_CREATE(&_fix);
+    datarouter_port_set_type(p, DATAROUTER_CHANNEL_sensor);
+    datarouter_port_add_handler(p, _h_a);
+    datarouter_port_add_handler(p, _h_b);
+
+    reset_hstate();
+    datarouter_send_sensor(p, "d", 1);
+    CHECK(_h_cnt == 2, "2 handlers: count=%d", _h_cnt);
+
+    datarouter_port_remove_handler(p, _h_a);
+
+    reset_hstate();
+    datarouter_send_sensor(p, "d", 1);
+    CHECK(_h_cnt == 1, "after remove: count=%d", _h_cnt);
+TEST_END()
+
+TEST_START(send_clear_handlers)
+    datarouter_port_t p = FIXTURE_CREATE(&_fix);
+    datarouter_port_set_type(p, DATAROUTER_CHANNEL_sensor);
+    datarouter_port_add_handler(p, _h_a);
+    datarouter_port_add_handler(p, _h_b);
+    datarouter_port_clear_handlers(p);
+
+    CHECK(datarouter_send_sensor(p, "d", 1) == -4, "expected -4 after clear");
+TEST_END()
+
+/* ================================================================
+ *  8. 接收回调
+ * ================================================================ */
+
+static int _rx_s;
+static void rx_s(uint32_t p, const void *d, size_t l) { (void)p; (void)d; (void)l; _rx_s++; }
+static int _rx_t;
+static void rx_t(uint32_t p, const void *d, size_t l) { (void)p; (void)d; (void)l; _rx_t++; }
+
+void datarouter_on_recv_sensor(uint32_t p, const void *d, size_t l) { rx_s(p, d, l); }
+void datarouter_on_recv_status(uint32_t p, const void *d, size_t l) { rx_t(p, d, l); }
+
+TEST_START(recv_callback)
+    _rx_s = _rx_t = 0;
+    datarouter_on_recv_sensor(0, "data", 4);
+    CHECK(_rx_s == 1, "sensor cb: %d", _rx_s);
+    CHECK(_rx_t == 0, "status cb: %d", _rx_t);
+    datarouter_on_recv_status(1, "data", 4);
+    CHECK(_rx_t == 1, "status cb: %d", _rx_t);
+    CHECK(_rx_s == 1, "sensor cb unchanged: %d", _rx_s);
+TEST_END()
+
+/* ================================================================
+ *  9. 错误处理
+ * ================================================================ */
+
+TEST_START(error_invalid_port)
+    CHECK(datarouter_send_sensor(999, "d", 1) == -2, NULL);
+    CHECK(datarouter_send_sensor(-1, "d", 1) == -2, NULL);
+TEST_END()
+
+TEST_START(error_deleted_port)
+    datarouter_port_t p = FIXTURE_CREATE(&_fix);
+    datarouter_port_set_type(p, DATAROUTER_CHANNEL_sensor);
+    datarouter_port_add_handler(p, _h);
+    datarouter_port_delete(p);
+    CHECK(datarouter_send_sensor(p, "d", 1) == -2, "expected -2");
+    _fix.count--;
+TEST_END()
+
+/* ================================================================
+ *  10. 零长与 NULL
+ * ================================================================ */
+
+TEST_START(send_zero_length)
+    datarouter_port_t p = FIXTURE_CREATE(&_fix);
+    datarouter_port_set_type(p, DATAROUTER_CHANNEL_sensor);
+    datarouter_port_add_handler(p, _h);
+
+    reset_hstate();
+    CHECK(datarouter_send_sensor(p, "x", 0) == 0, NULL);
+    CHECK(_h_cnt == 1, "handler called %d", _h_cnt);
+TEST_END()
+
+TEST_START(send_null_data)
+    datarouter_port_t p = FIXTURE_CREATE(&_fix);
+    datarouter_port_set_type(p, DATAROUTER_CHANNEL_sensor);
+    datarouter_port_add_handler(p, _h);
+
+    reset_hstate();
+    CHECK(datarouter_send_sensor(p, NULL, 0) == 0, NULL);
+    CHECK(_h_cnt == 1, "handler called %d", _h_cnt);
+TEST_END()
+
+/* ================================================================
+ *  主函数
+ * ================================================================ */
+
+#define RUN(name) do { reset_hstate(); test_##name(); } while (0)
+
+int main(void)
+{
+    printf("==== DataRouter Unit Tests ====\n\n");
+
+    printf("[uninitialized]\n");
+    RUN(error_uninit);
+
+    datarouter_init();
+
+    printf("\n[port management]\n");
+    RUN(port_create_basic);
+    RUN(port_create_multiple);
+    RUN(port_create_reuse);
+    RUN(port_delete_invalid);
+    RUN(port_delete_twice);
+    RUN(port_default_state);
+    RUN(port_create_max);
+    printf("\n");
+
+    datarouter_reset();  datarouter_init();
+    printf("[type set/get]\n");
+    RUN(type_set_get);
+    RUN(type_clear);
+    RUN(type_switch);
+    RUN(type_from_invalid);
+    printf("\n");
+
+    printf("[multi-handler add/remove]\n");
+    RUN(handler_add_one);
+    RUN(handler_add_multiple);
+    RUN(handler_add_duplicate);
+    RUN(handler_add_max);
+    RUN(handler_remove);
+    RUN(handler_remove_not_found);
+    RUN(handler_clear);
+    RUN(handler_from_invalid);
+    printf("\n");
+
+    printf("[channel introspection]\n");
+    RUN(channel_count);
+    RUN(channel_names);
+    RUN(channel_descs);
+    RUN(channel_invalid_id);
+    printf("\n");
+
+    printf("[send — one-to-many broadcast]\n");
+    RUN(send_one_handler);
+    RUN(send_multi_handlers);
+    RUN(send_type_mismatch);
+    RUN(send_no_handler);
+    RUN(send_three_channels);
+    RUN(send_remove_handler);
+    RUN(send_clear_handlers);
+    RUN(send_zero_length);
+    RUN(send_null_data);
+    printf("\n");
+
+    printf("[receive callback]\n");
+    RUN(recv_callback);
+    printf("\n");
+
+    printf("[error handling]\n");
+    RUN(error_invalid_port);
+    RUN(error_deleted_port);
+    printf("\n");
+
+    printf("==============================\n");
+    printf("  total: %d  |  pass: %d  |  fail: %d\n\n",
+           _total_run, _total_pass, _total_fail);
+
+    return _total_fail > 0 ? 1 : 0;
+}