### Basic sMQTTBroker Setup

Source: https://context7.com/terrorsl/smqttbroker/llms.txt

A minimal setup for sMQTTBroker without subclassing, suitable for quickstarts where event callbacks are not needed. Initializes the broker on the specified port after WiFi connection.

```cpp
#include <sMQTTBroker.h>

sMQTTBrokerWithoutEvent broker;

void setup() {
  WiFi.begin("MySSID", "MyPassword");
  while (WiFi.status() != WL_CONNECTED) delay(500);
  broker.init(1883);
}

void loop() {
  broker.update();
}
// Any MQTT client can now connect, subscribe, and publish freely
// with no authentication or event filtering applied
```

--------------------------------

### Initialize sMQTTBroker

Source: https://github.com/terrorsl/smqttbroker/blob/main/readme.md

Instantiate the sMQTTBroker and initialize it with a specified port. This is a basic setup for the broker.

```c++
sMQTTBrokerWithoutEvent broker;
#define PORT 1883
```

```c++
void setup(){
  broker.init(PORT);
};
```

--------------------------------

### Initialize sMQTTBroker

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/md_readme.html

Include the sMQTTBroker library and initialize the broker in the setup function. The update function must be called in the loop.

```c++
#include<sMQTTBroker.h>

sMQTTBroker broker;

#define PORT 1883

void setup(){

broker.init(PORT);

};

void loop(){

broker.update();

};
```

--------------------------------

### Include sMQTTBroker Library

Source: https://github.com/terrorsl/smqttbroker/blob/main/readme.md

Include the sMQTTBroker library header file to start using the broker.

```c++
#include<sMQTTBroker.h>
```

--------------------------------

### Initialize and Start sMQTTBroker

Source: https://context7.com/terrorsl/smqttbroker/llms.txt

Sets up the TCP server on the specified port and begins listening for incoming MQTT client connections. Pass `checkWifiConnection=true` to enable automatic WiFi reconnection handling inside the `update()` loop. Returns `true` on successful initialization.

```cpp
#include <ESP8266WiFi.h>
#include <sMQTTBroker.h>

sMQTTBroker broker;
#define MQTT_PORT 1883

void setup() {
  Serial.begin(115200);
  WiFi.begin("MySSID", "MyPassword");
  while (WiFi.status() != WL_CONNECTED) delay(500);

  Serial.print("IP: ");
  Serial.println(WiFi.localIP());

  // Initialize broker on port 1883, with WiFi connection checking enabled
  if (broker.init(MQTT_PORT, true)) {
    Serial.println("MQTT broker started");
  } else {
    Serial.println("Failed to start broker");
  }
}

void loop() {
  broker.update();
}
```

--------------------------------

### sMQTTBroker::init

Source: https://context7.com/terrorsl/smqttbroker/llms.txt

Initializes and starts the MQTT broker on a specified TCP port. It can optionally enable automatic WiFi connection checking for reconnection handling. Returns true if initialization is successful.

```APIDOC
## sMQTTBroker::init — Initialize and start the broker

Sets up the TCP server on the specified port and begins listening for incoming MQTT client connections. Pass `checkWifiConnection=true` to enable automatic WiFi reconnection handling inside the `update()` loop. Returns `true` on successful initialization.

### Method
```cpp
bool init(uint16_t port, bool checkWifiConnection = false)
```

### Parameters
#### Path Parameters
- **port** (uint16_t) - Required - The TCP port to listen on for MQTT connections.
- **checkWifiConnection** (bool) - Optional - If true, enables automatic WiFi reconnection handling.

### Request Example
```cpp
#include <ESP8266WiFi.h>
#include <sMQTTBroker.h>

sMQTTBroker broker;
#define MQTT_PORT 1883

void setup() {
  Serial.begin(115200);
  WiFi.begin("MySSID", "MyPassword");
  while (WiFi.status() != WL_CONNECTED) delay(500);

  Serial.print("IP: ");
  Serial.println(WiFi.localIP());

  // Initialize broker on port 1883, with WiFi connection checking enabled
  if (broker.init(MQTT_PORT, true)) {
    Serial.println("MQTT broker started");
  } else {
    Serial.println("Failed to start broker");
  }
}

void loop() {
  broker.update();
}
```
```

--------------------------------

### Custom Authentication Logic

Source: https://context7.com/terrorsl/smqttbroker/llms.txt

Implement custom authentication by returning false from `onEvent(NewClient_sMQTTEventType)` to trigger `sMQTTConnReturnBadUsernameOrPassword`. This example checks a hardcoded username and password.

```cpp
// Return false from onEvent(NewClient_sMQTTEventType) to trigger
// sMQTTConnReturnBadUsernameOrPassword automatically.
bool onEvent(sMQTTEvent *event) override {
  if (event->Type() == NewClient_sMQTTEventType) {
    auto *e = static_cast<sMQTTNewClientEvent*>(event);
    return (e->Login() == "user" && e->Password() == "pass");
  }
  return true;
}
```

--------------------------------

### Get variable header start pointer

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/s_m_q_t_t_message_8h_source.html

Returns a pointer to the beginning of the variable header section within the message buffer. Assumes the message state is advanced enough to have a variable header.

```cpp
const char* getVHeader() const { return &buffer[vheader]; }
```

--------------------------------

### Get QoS level

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/s_m_q_t_t_message_8h_source.html

Extracts the Quality of Service (QoS) level from the fixed header of a PUBLISH message. Returns 0, 1, or 2.

```cpp
unsigned char QoS() {
    return (buffer[0] & 0x6)>>1;
    }
```

--------------------------------

### Get message type

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/s_m_q_t_t_message_8h_source.html

Returns the type of the MQTT message. This is determined from the first byte of the buffer if the message state is 'Complete'.

```cpp
Type type() const
    {
    return state == Complete ? static_cast<Type>(buffer[0] & 0XF0) : Unknown;
    }
```

--------------------------------

### init()

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/functions_func.html

Initializes the sMQTTBroker.

```APIDOC
## init()

### Description
Initializes the sMQTTBroker.

### Method
(Implicitly called or part of constructor)

### Parameters
None explicitly documented.

### Response
None explicitly documented.
```

--------------------------------

### init()

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/functions.html

Initializes the sMQTTBroker. This is a class method.

```APIDOC
## init()

### Description
Initializes the sMQTTBroker.

### Method
(Not specified, likely a constructor or initialization function)

### Endpoint
N/A

### Parameters
None explicitly documented.

### Request Example
N/A

### Response
N/A
```

--------------------------------

### init

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_broker.html

Initializes the MQTT broker on the specified port. Optionally checks for Wi-Fi connection.

```APIDOC
## init

### Description
Initializes the MQTT broker.

### Method
bool init(unsigned short port, bool checkWifiConnection = false)

### Parameters
* **port** (unsigned short) - The port number to initialize the broker on.
* **checkWifiConnection** (bool) - Optional. If true, checks for Wi-Fi connection before initializing.

### Return Value
Returns true if initialization is successful, false otherwise.
```

--------------------------------

### Get end pointer of message buffer

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/s_m_q_t_t_message_8h_source.html

Returns a pointer to the end of the internal message buffer. Useful for iterating or calculating remaining data.

```cpp
const char* end() const { return &buffer[0] + buffer.size(); }
```

--------------------------------

### sMQTTBroker::init

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/s_m_q_t_t_broker_8h_source.html

Initializes the MQTT broker on the specified port. Optionally checks for Wi-Fi connection.

```APIDOC
## init

### Description
Initializes the MQTT broker on the specified port. Optionally checks for Wi-Fi connection.

### Method
bool

### Parameters
- **port** (unsigned short) - The port number to run the broker on.
- **checkWifiConnection** (bool) - Optional. If true, checks for Wi-Fi connection before starting. Defaults to false.

### Definition
sMQTTBroker.h:16
```

--------------------------------

### Get string from buffer

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/s_m_q_t_t_message_8h_source.html

A static utility function to extract a length-prefixed string from a buffer. It updates the buffer pointer and provides the string's length.

```cpp
static void getString(const char* &buff, unsigned short &len);
```

--------------------------------

### sMQTTBroker Constructor

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_broker-members.html

Initializes the sMQTTBroker with a specified port and an optional Wi-Fi connection check.

```APIDOC
## init

### Description
Initializes the sMQTTBroker with a specified port and an optional Wi-Fi connection check.

### Method Signature
`init(unsigned short port, bool checkWifiConnection=false)`
```

--------------------------------

### sMQTTClient Constructor

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_client-members.html

Constructs a new sMQTTClient instance.

```APIDOC
## sMQTTClient(sMQTTBroker *parent, TCPClient &client)

### Description
Initializes a new instance of the sMQTTClient class, associating it with a parent sMQTTBroker and a TCPClient.

### Method
N/A (This is a C++ constructor)

### Parameters
- **parent** (*sMQTTBroker* *) - A pointer to the parent sMQTTBroker.
- **client** (*TCPClient* &) - A reference to the TCPClient used for communication.
```

--------------------------------

### Filter Publish Events with sMQTTEventType

Source: https://context7.com/terrorsl/smqttbroker/llms.txt

Use the `sMQTTEventType` enum to identify specific event types within the `onEvent` handler. This example specifically checks for and processes publish events.

```cpp
bool onEvent(sMQTTEvent *event) override {
  if (event->Type() == Public_sMQTTEventType) {
    auto *pub = static_cast<sMQTTPublicClientEvent*>(event);
    // Forward to another system, log, or react
    Serial.println(pub->Payload().c_str());
  }
  return true;
}
```

--------------------------------

### Handle New Client Connections and Credentials

Source: https://context7.com/terrorsl/smqttbroker/llms.txt

Process new client connections using `sMQTTNewClientEvent`. You can access the client ID, login, and password. Return `false` to reject the connection if credentials are not valid.

```cpp
case NewClient_sMQTTEventType: {
  auto *e = static_cast<sMQTTNewClientEvent*>(event);
  std::string id  = e->Client()->getClientId();
  std::string usr = e->Login();
  std::string pwd = e->Password();

  // Allow only known clients
  if (usr == "sensor_node" && pwd == "pass123") {
    Serial.printf("Accepted: %s\n", id.c_str());
    return true;
  }
  Serial.printf("Rejected: %s (bad credentials)\n", id.c_str());
  return false;
}
```

--------------------------------

### Handle Client Publish Events and Actions

Source: https://context7.com/terrorsl/smqttbroker/llms.txt

React to client publish events using `sMQTTPublicClientEvent`. This snippet demonstrates how to check the topic for specific commands like 'home/command/reboot' or sensor data.

```cpp
case Public_sMQTTEventType: {
  auto *e = static_cast<sMQTTPublicClientEvent*>(event);

  if (e->Topic() == "home/command/reboot") {
    Serial.println("Reboot command received — restarting ESP");
    ESP.restart();
  }

  if (e->Topic().rfind("home/sensor/", 0) == 0) {
    Serial.printf("[%s] %s = %s\n",
      e->Client()->getClientId().c_str(),
      e->Topic().c_str(),
      e->Payload().c_str());
  }
  break;
}
```

--------------------------------

### Client

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_public_client_event.html

Returns the associated sMQTTClient object.

```APIDOC
## Client

### Description
Returns a pointer to the associated sMQTTClient object.

### Returns
- [sMQTTClient](classs_m_q_t_t_client.html) *

### Method
[sMQTTClient](classs_m_q_t_t_client.html) *
```

--------------------------------

### Client()

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_new_client_event.html

Returns a pointer to the sMQTTClient associated with this event.

```APIDOC
## Client()

### Description
Retrieves the sMQTTClient object associated with this new client event.

### Signature
sMQTTClient* Client()

### Returns
A pointer to the sMQTTClient.
```

--------------------------------

### Login()

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/functions.html

Handles client login events. This method is associated with sMQTTNewClientEvent.

```APIDOC
## Login()

### Description
Handles client login events. This method is part of the sMQTTNewClientEvent class.

### Method
(Not specified)

### Endpoint
N/A

### Parameters
None explicitly documented.

### Request Example
N/A

### Response
N/A
```

--------------------------------

### Login()

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_new_client_event.html

Retrieves the login string for the new client.

```APIDOC
## Login()

### Description
Gets the login username for the newly connected client.

### Signature
std::string Login()

### Returns
The client's login username.
```

--------------------------------

### restart

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_broker.html

Restarts the Wi-Fi server for the MQTT broker.

```APIDOC
## restart

### Description
Restarts the underlying Wi-Fi server associated with the MQTT broker.

### Method
void restart()

### Parameters
None

### Return Value
None
```

--------------------------------

### sMQTTTopic Constructors

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_topic.html

Constructors for creating an sMQTTTopic object.

```APIDOC
## sMQTTTopic Constructors

### Description
Constructors for creating an sMQTTTopic object with different initializations.

### Methods
- `sMQTTTopic(const char *name, char QoS=0)`
- `sMQTTTopic(const char *name, unsigned short nameLen, const char *payload, unsigned short payloadLen)`
- `sMQTTTopic(std::string &name, std::string &payload, char QoS=0)`
- `sMQTTTopic(sMQTTTopic *other)`
```

--------------------------------

### restart()

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/functions.html

Restarts the sMQTTBroker. This is a class method.

```APIDOC
## restart()

### Description
Restarts the sMQTTBroker.

### Method
(Not specified)

### Endpoint
N/A

### Parameters
None explicitly documented.

### Request Example
N/A

### Response
N/A
```

--------------------------------

### Login()

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/functions_func.html

Handles client login events.

```APIDOC
## Login()

### Description
Handles client login events, likely returning information about a new client connection.

### Method
(Likely an event handler or callback)

### Parameters
None explicitly documented.

### Response
Returns a [sMQTTNewClientEvent](classs_m_q_t_t_new_client_event.html#a86b87f9a291abbda4a4d73e3c7192b76) object.
```

--------------------------------

### restart

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_broker-members.html

Restarts the sMQTTBroker.

```APIDOC
## restart

### Description
Restarts the sMQTTBroker.

### Method Signature
`restart()`
```

--------------------------------

### sMQTTClient Constructor

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_client.html

Constructs an sMQTTClient object, associating it with a parent sMQTTBroker and a TCPClient instance.

```APIDOC
## sMQTTClient Constructor

### Description
Initializes a new instance of the sMQTTClient class.

### Parameters
*   **parent** (*sMQTTBroker **) - A pointer to the parent sMQTTBroker.
*   **client** (*TCPClient &&*) - A reference to the TCPClient instance used for communication.
```

--------------------------------

### sMQTTTopic Constructors

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_topic-members.html

Constructors for the sMQTTTopic class.

```APIDOC
## sMQTTTopic(const char *name, char QoS=0)

### Description
Constructor for sMQTTTopic.

### Parameters
- **name** (const char *) - The topic name.
- **QoS** (char) - The Quality of Service level, defaults to 0.
```

```APIDOC
## sMQTTTopic(const char *name, unsigned short nameLen, const char *payload, unsigned short payloadLen)

### Description
Constructor for sMQTTTopic with payload.

### Parameters
- **name** (const char *) - The topic name.
- **nameLen** (unsigned short) - The length of the topic name.
- **payload** (const char *) - The topic payload.
- **payloadLen** (unsigned short) - The length of the payload.
```

```APIDOC
## sMQTTTopic(std::string &name, std::string &payload, char QoS=0)

### Description
Constructor for sMQTTTopic using std::string.

### Parameters
- **name** (std::string &) - The topic name.
- **payload** (std::string &) - The topic payload.
- **QoS** (char) - The Quality of Service level, defaults to 0.
```

```APIDOC
## sMQTTTopic(sMQTTTopic *other)

### Description
Copy constructor for sMQTTTopic.
```

--------------------------------

### Process Broker Events with `update()`

Source: https://context7.com/terrorsl/smqttbroker/llms.txt

Must be called repeatedly from `loop()`. Handles accepting new TCP connections, reading incoming MQTT packets, processing control messages, and maintaining keep-alive timers. If `checkWifiConnection` was set to `true` at init, it also monitors WiFi status and calls `restart()` automatically on reconnection.

```cpp
void loop() {
  broker.update(); // Call as frequently as possible for responsive message handling
}
```

--------------------------------

### Client Member Function

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_remove_client_event.html

Returns a pointer to the associated sMQTTClient object.

```APIDOC
## Client()

### Description
Returns a pointer to the sMQTTClient object associated with this event.

### Returns
- *sMQTTClient* * - A pointer to the sMQTTClient object.
```

--------------------------------

### sMQTTNewClientEvent Constructor

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_new_client_event.html

Constructs a new sMQTTNewClientEvent object with the provided client, login, and password.

```APIDOC
## sMQTTNewClientEvent Constructor

### Description
Initializes a new client event with associated client, login, and password details.

### Signature
sMQTTNewClientEvent(sMQTTClient *client, std::string &login, std::string &password)
```

--------------------------------

### Platform Macros for ESP8266/ESP32/WT32-ETH01

Source: https://context7.com/terrorsl/smqttbroker/llms.txt

Automatically maps TCPClient and TCPServer to platform-specific WiFi types. Define `SMQTT_WT32_ETH01` before including for WT32-ETH01 boards. Includes notes on debug logging for ESP8266 and ESP32.

```cpp
// For WT32-ETH01 (Ethernet ESP32 board), define before including:
#define SMQTT_WT32_ETH01
#include <sMQTTBroker.h>

// For ESP8266: TCPClient = WiFiClient, TCPServer = WiFiServer (ESP8266WiFi.h)
// For ESP32:   TCPClient = WiFiClient, TCPServer = WiFiServer (WiFi.h)
// Debug logging on ESP8266 (outputs via DEBUG_ESP_PORT if defined):
// #define DEBUG_ESP_PORT Serial
// Debug logging on ESP32 uses ESP_LOGD with tag "sMQTTBroker"
```

--------------------------------

### sMQTTTopic Class Definition

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/s_m_q_t_t_topic_8h_source.html

Defines the sMQTTTopic class, its constructors, and methods for managing topic data, matching, and subscriptions. Includes members for topic name, payload, QoS, and a list of subscribed clients.

```cpp
#define SINGLE_LEVEL_WILDCARD "+"
#define TOPIC_LEVEL_SEPARATOR "/"
#define MULTI_LEVEL_WILDCARD "#"

#include<string>

class sMQTTTopic
{
public:
 sMQTTTopic(const char *name,char QoS=0);
 sMQTTTopic(const char *name, unsigned short nameLen, const char *payload, unsigned short payloadLen);
 sMQTTTopic(std::string &name,std::string &payload, char QoS=0);
 sMQTTTopic(sMQTTTopic *other);
 virtual ~sMQTTTopic();
 void update(sMQTTTopic *other)
 {
 if (_payload)
 delete[] _payload;
 _name = other->Name();

 if (other->Payload())
 {
 _payload = new char[strlen(other->Payload()) + 1];
 strcpy(_payload, other->Payload());
 }
 else
 _payload = 0;
 qos = other->QoS();
 }
 const char *Name() {
 return _name.c_str();
 }
 const char *Payload() {
 return _payload;
 }
 const unsigned char QoS() {
 return qos;
 }
 bool match(sMQTTTopic *other);
 bool match(const std::string &other);
 void subscribe(sMQTTClient *client);
 bool unsubscribe(sMQTTClient *client) {
 sMQTTClientList::iterator cli; for (cli = clients.begin(); cli != clients.end(); cli++)if (*cli == client) { clients.erase(cli); break; }
 return clients.empty();
 }
 const sMQTTClientList getSubscribeList() {
 return clients;
 }
protected:
 std::string _name;
 char *_payload;
 unsigned char qos;
 unsigned short _payloadLen;
 // subscribe to topic
 sMQTTClientList clients;
};

typedef std::vector<sMQTTTopic*> sMQTTTopicList;
```

--------------------------------

### sMQTTMessage Class Overview

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/s_m_q_t_t_message_8h_source.html

This section details the sMQTTMessage class, its constructors, and public methods for managing MQTT messages.

```APIDOC
## Class sMQTTMessage

### Description
Represents an MQTT message, handling its construction, parsing, and transmission.

### Methods

#### Constructor
- `sMQTTMessage()`: Default constructor.
- `sMQTTMessage(Type t, unsigned char bits_d3_d0 = 0)`: Constructor to initialize with a specific message type and flags.

#### Public Methods
- `void incoming(char byte)`: Processes a single incoming byte of the message.
- `void add(char byte)`: Alias for `incoming(char byte)`.
- `void add(const char* p, size_t len, bool addLength = true)`: Adds a block of data to the message buffer. Optionally prepends length information.
- `void add(const std::string &str)`: Adds a string to the message buffer.
- `const char* end() const`: Returns a pointer to the end of the message buffer.
- `const char* getVHeader() const`: Returns a pointer to the variable header section of the message.
- `void reset()`: Resets the message object to an initial state.
- `Type type() const`: Returns the type of the message if it's complete, otherwise `Unknown`.
- `unsigned char QoS()`: Returns the Quality of Service level of the message.
- `bool isRetained()`: Checks if the message is retained.
- `sMQTTError sendTo(sMQTTClient *client, bool needRecalc = true)`: Sends the message to the specified client.

#### Static Methods
- `static void getString(const char* &buff, unsigned short &len)`: Extracts a length-prefixed string from a buffer.

### Enums

#### Type
Represents the different types of MQTT messages.
- `Unknown = 0`
- `Connect = 0x10`
- `ConnAck = 0x20`
- `Publish = 0x30`
- `PubAck = 0x40`
- `PubRec = 0x50`
- `PubRel = 0x60`
- `PubComp = 0x70`
- `Subscribe = 0x80`
- `SubAck = 0x90`
- `UnSubscribe = 0xA0`
- `UnSuback = 0xB0`
- `PingReq = 0xC0`
- `PingResp = 0xD0`
- `Disconnect = 0xE0`

#### State
Represents the current parsing or construction state of the message.
- `FixedHeader = 0`
- `Length = 1`
- `VariableHeader = 2`
- `PayLoad = 3`
- `Complete = 4`
- `Error = 5`
- `Create = 6
```

--------------------------------

### sMQTTLostConnectionEvent()

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_lost_connection_event-members.html

Constructor for sMQTTLostConnectionEvent. Initializes a new instance of the sMQTTLostConnectionEvent class.

```APIDOC
## sMQTTLostConnectionEvent()

### Description
Constructor for sMQTTLostConnectionEvent. Initializes a new instance of the sMQTTLostConnectionEvent class.

### Method
`sMQTTLostConnectionEvent()`

### Parameters
None

### Returns
An instance of sMQTTLostConnectionEvent.
```

--------------------------------

### Windows Platform Definitions

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/s_m_q_t_tplatform_8h_source.html

Defines dummy TCPClient and TCPServer classes for Windows when no specific network library is included. Use this when targeting Windows without specific network dependencies.

```cpp
#define SMQTT_DEPRECATED(msg) [[deprecated(msg)]]

#if defined(WIN32)
class TCPClient {
public:
 bool available() { return false; };
 char read() { return 0; }
 bool connected() {
 return false;
 }
 void stop() {}
 void write(const char *, int) {}
};
class TCPServer {
public:
 TCPServer(short) {}
 void begin() {}
};
#define SMQTT_LOGD
```

--------------------------------

### Handle Subscribe/Unsubscribe Events

Source: https://context7.com/terrorsl/smqttbroker/llms.txt

Fired for both subscribe and unsubscribe actions. Provides the client ID and the topic filter, which may include wildcards.

```cpp
case Subscribe_sMQTTEventType: {
  auto *e = static_cast<sMQTTSubUnSubClientEvent*>(event);
  Serial.printf("SUB  client=%s  filter=%s\n",
    e->Client()->getClientId().c_str(),
    e->Topic().c_str());
  break;
}
```

```cpp
case UnSubscribe_sMQTTEventType: {
  auto *e = static_cast<sMQTTSubUnSubClientEvent*>(event);
  Serial.printf("UNSUB client=%s  filter=%s\n",
    e->Client()->getClientId().c_str(),
    e->Topic().c_str());
  break;
}
```

--------------------------------

### Internal message creation helper

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/s_m_q_t_t_message_8h_source.html

Private helper function to initialize the message buffer with the message type and reserve space for the length. Sets the initial state to 'Create'.

```cpp
void create(Type type)
        {
        buffer.push_back((char)type);
        buffer.push_back('\0'); // reserved for msg length
        vheader = 2;
        size = 0;
        state = Create;
        }
```

--------------------------------

### sMQTTBroker::restart

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/s_m_q_t_t_broker_8h_source.html

Restarts the MQTT broker's Wi-Fi server.

```APIDOC
## restart

### Description
Restarts the MQTT broker's Wi-Fi server.

### Method
void

### Definition
sMQTTBroker.h:22
```

--------------------------------

### Publish Messages with `sMQTTBroker::publish`

Source: https://context7.com/terrorsl/smqttbroker/llms.txt

Publishes a message from the broker itself to all clients subscribed to the given topic. Supports QoS 0 and QoS 1. The `retain` flag causes the message to be stored and immediately delivered to new subscribers.

```cpp
#include <sMQTTBroker.h>

sMQTTBroker broker;

void setup() {
  WiFi.begin("MySSID", "MyPassword");
  while (WiFi.status() != WL_CONNECTED) delay(500);
  broker.init(1883);

  // Publish a retained status message at QoS 1
  broker.publish("home/status", "online", 1, true);
}

void loop() {
  broker.update();

  // Publish sensor reading every 5 seconds at QoS 0
  static unsigned long last = 0;
  if (millis() - last > 5000) {
    last = millis();
    float temp = 22.5; // read from sensor
    broker.publish("home/sensor/temperature", String(temp).c_str(), 0, false);
  }
}
```

--------------------------------

### sMQTTMessage Public Member Functions

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_message.html

Provides methods for constructing, parsing, and managing MQTT messages.

```APIDOC
## sMQTTMessage Public Member Functions

### Constructor

```cpp
sMQTTMessage(Type t, unsigned char bits_d3_d0 = 0)
```
Constructs an sMQTTMessage object with a specified type and initial bits.

### `incoming`

```cpp
void incoming(char byte)
```
Processes a single incoming byte for message parsing.

### `add` (overloaded)

```cpp
void add(char byte)
void add(const char *p, size_t len, bool addLength = true)
void add(const std::string &str)
```
Adds data to the message. Overloaded versions handle single bytes, character arrays with optional length prefix, and std::string objects.

### `end`

```cpp
const char *end() const
```
Returns a pointer to the end of the message data.

### `getVHeader`

```cpp
const char *getVHeader() const
```
Returns a pointer to the variable header of the MQTT message.

### `reset`

```cpp
void reset()
```
Resets the message object to its initial state.

### `type`

```cpp
Type type() const
```
Returns the type of the MQTT message.

### `QoS`

```cpp
unsigned char QoS() 
```
Returns the Quality of Service level of the message.

### `isRetained`

```cpp
bool isRetained() const
```
Checks if the message is retained.

### `sendTo`

```cpp
sMQTTError sendTo(sMQTTClient *client, bool needRecalc = true)
```
Sends the MQTT message to the specified client. `needRecalc` indicates if the length needs recalculation.
```

--------------------------------

### publish()

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/functions_func.html

Publishes a message through the sMQTTBroker.

```APIDOC
## publish()

### Description
Publishes a message through the sMQTTBroker.

### Method
(Likely a core messaging function)

### Parameters
None explicitly documented.

### Response
None explicitly documented.
```

--------------------------------

### publish()

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/functions.html

Publishes a message using the sMQTTBroker. This is a class method.

```APIDOC
## publish()

### Description
Publishes a message using the sMQTTBroker.

### Method
(Not specified)

### Endpoint
N/A

### Parameters
None explicitly documented.

### Request Example
N/A

### Response
N/A
```

--------------------------------

### sMQTTNewClientEvent Class

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/s_m_q_t_t_event_8h_source.html

Represents an event when a new client connects to the MQTT broker.

```APIDOC
## sMQTTNewClientEvent

### Description
Represents an event when a new client connects to the MQTT broker. It stores information about the connected client, login, and password.

### Methods
- **sMQTTNewClientEvent([sMQTTClient](classs_m_q_t_t_client.html) *client, std::string &login, std::string &password)**: Constructor.
- **Client()**: Returns a pointer to the connected client.
- **Login()**: Returns the login username.
- **Password()**: Returns the password.
```

--------------------------------

### sMQTTMessage Constructor with Type

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/s_m_q_t_t_message_8h_source.html

Constructs an sMQTTMessage with a specified type and optional initial bits for the fixed header. Used for creating outgoing messages.

```cpp
sMQTTMessage(Type t, unsigned char bits_d3_d0 = 0);
```

--------------------------------

### ESP32 Platform Definitions

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/s_m_q_t_tplatform_8h_source.html

Includes WiFi.h for ESP32 and defines TCPClient and TCPServer using WiFiClient and WiFiServer. It also defines a logging macro SMQTT_LOGD using ESP_LOGD for ESP32.

```cpp
#elif defined(ESP32)
#include <WiFi.h>
#ifdef SMQTT_WT32_ETH01
#include <ETH.h>
#endif
#define TCPClient WiFiClient
#define TCPServer WiFiServer
static const char *SMQTTTAG = "sMQTTBroker";
#define SMQTT_LOGD(...) ESP_LOGD(SMQTTTAG,__VA_ARGS__)
#else
#error "unknown platform"
```

--------------------------------

### sMQTTTopic Methods

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_topic-members.html

Methods available for the sMQTTTopic class.

```APIDOC
## getSubscribeList()

### Description
Retrieves the list of subscribers for the topic.

### Returns
(List of subscribers)
```

```APIDOC
## match(sMQTTTopic *other)

### Description
Checks if this topic matches another sMQTTTopic.

### Parameters
- **other** (sMQTTTopic *) - The other sMQTTTopic to compare with.

### Returns
(Boolean indicating if topics match)
```

```APIDOC
## match(const std::string &other)

### Description
Checks if this topic matches a given topic name string.

### Parameters
- **other** (const std::string &) - The topic name string to compare with.

### Returns
(Boolean indicating if topics match)
```

```APIDOC
## Name()

### Description
Gets the name of the topic.

### Returns
(Topic name)
```

```APIDOC
## Payload()

### Description
Gets the payload of the topic.

### Returns
(Topic payload)
```

```APIDOC
## QoS()

### Description
Gets the Quality of Service level of the topic.

### Returns
(QoS level)
```

```APIDOC
## subscribe(sMQTTClient *client)

### Description
Subscribes a client to this topic.

### Parameters
- **client** (sMQTTClient *) - The client to subscribe.
```

```APIDOC
## unsubscribe(sMQTTClient *client)

### Description
Unsubscribes a client from this topic.

### Parameters
- **client** (sMQTTClient *) - The client to unsubscribe.
```

```APIDOC
## update(sMQTTTopic *other)

### Description
Updates this topic with the content of another sMQTTTopic.

### Parameters
- **other** (sMQTTTopic *) - The other sMQTTTopic to update from.
```

--------------------------------

### Password()

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_new_client_event.html

Retrieves the password string for the new client.

```APIDOC
## Password()

### Description
Gets the password for the newly connected client.

### Signature
std::string Password()

### Returns
The client's password.
```

--------------------------------

### sMQTTTopicRetain Constructor

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_topic_retain-members.html

Constructor for the sMQTTTopicRetain class.

```APIDOC
## sMQTTTopicRetain(const char *name, const char *payload)

### Description
Constructor for the sMQTTTopicRetain class.

### Parameters
#### Path Parameters
- **name** (const char *) - Description not available
- **payload** (const char *) - Description not available
```

--------------------------------

### update()

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/functions_func.html

Updates the sMQTTBroker configuration or state.

```APIDOC
## update()

### Description
Updates the sMQTTBroker configuration or state.

### Method
(Likely a configuration or control function)

### Parameters
None explicitly documented.

### Response
None explicitly documented.
```

--------------------------------

### sMQTTMessage Constructors

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_message-members.html

Constructors for creating sMQTTMessage objects.

```APIDOC
## sMQTTMessage Constructors

### Description
Initializes a new instance of the sMQTTMessage class.

### Constructors
- `sMQTTMessage()`
- `sMQTTMessage(Type t, unsigned char bits_d3_d0 = 0)`
```

--------------------------------

### sMQTTMessage Static Public Member Functions

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_message.html

Provides static utility functions for string manipulation within MQTT messages.

```APIDOC
## sMQTTMessage Static Public Member Functions

### `getString`

```cpp
static void getString(const char *&buff, unsigned short &len)
```
Extracts a string from a buffer, updating the buffer pointer and length. This is likely used for parsing UTF-8 encoded strings in MQTT headers.
```

--------------------------------

### write

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_client.html

Writes data to the MQTT client's output stream.

```APIDOC
## write

### Description
Sends a buffer of data to the connected MQTT broker.

### Method
`void write(const char *buf, size_t length)`

### Parameters
*   **buf** (*const char **) - A pointer to the buffer containing the data to be sent.
*   **length** (*size_t*) - The number of bytes to send from the buffer.
```

--------------------------------

### sMQTTNewClientEvent Constructors

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_new_client_event-members.html

Constructors for the sMQTTNewClientEvent class.

```APIDOC
## sMQTTNewClientEvent(sMQTTClient *, std::string &, std::string &)

### Description
Constructor for sMQTTNewClientEvent.

### Parameters
- **sMQTTClient 
ofoam** (sMQTTClient *) - Pointer to sMQTTClient.
- **std::string &** - First string parameter.
- **std::string &** - Second string parameter.
```

--------------------------------

### sMQTTTopicRetain Constructor

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_topic_retain.html

Constructs a new sMQTTTopicRetain object with a given name and payload.

```APIDOC
## sMQTTTopicRetain(const char *name, const char *payload)

### Description
Constructs a new sMQTTTopicRetain object.

### Parameters
* **name** (const char *) - The name of the topic.
* **payload** (const char *) - The payload of the retained message.
```

--------------------------------

### QoS

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_topic.html

Retrieves the Quality of Service level for the topic.

```APIDOC
## QoS

### Description
Returns the Quality of Service (QoS) level configured for this topic.

### Method
`const unsigned char QoS()`

### Returns
- `const unsigned char` - The QoS level (0, 1, or 2).
```

--------------------------------

### sMQTTNewClientEvent Methods

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_new_client_event-members.html

Public methods available for sMQTTNewClientEvent.

```APIDOC
## Client()

### Description
Represents a client.

### Method
(Implicitly public, as it's a constructor-like name in a member list)

### Endpoint
N/A (Class method)
```

```APIDOC
## Login()

### Description
Handles client login.

### Method
(Implicitly public, as it's a method name in a member list)

### Endpoint
N/A (Class method)
```

```APIDOC
## Password()

### Description
Handles client password.

### Method
(Implicitly public, as it's a method name in a member list)

### Endpoint
N/A (Class method)
```

--------------------------------

### Topic

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_public_client_event.html

Returns the topic of the client event.

```APIDOC
## Topic

### Description
Returns the topic associated with this client event.

### Returns
- std::string - The topic of the event.

### Method
std::string
```

--------------------------------

### sMQTTMessage default constructor

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/s_m_q_t_t_message_8h_source.html

Default constructor for sMQTTMessage. Initializes an empty message object.

```cpp
sMQTTMessage();
```

--------------------------------

### sMQTTPublicClientEvent Constructor

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_public_client_event.html

Constructs a new sMQTTPublicClientEvent object.

```APIDOC
## sMQTTPublicClientEvent

### Description
Constructs a new sMQTTPublicClientEvent object with the specified client and topic.

### Parameters
#### Path Parameters
- **client** (*sMQTTClient**)
- **topic** (const std::string &)

### Method
Constructor
```

--------------------------------

### sMQTTEvent Constructor

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_event-members.html

Constructs an sMQTTEvent object with a specified type.

```APIDOC
## sMQTTEvent(unsigned char type)

### Description
Constructor for the sMQTTEvent class.

### Parameters
#### Path Parameters
- **type** (unsigned char) - Description of the type parameter.
```

--------------------------------

### sMQTTEvent Constructor

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_event.html

Constructs an sMQTTEvent object with a specified type.

```APIDOC
## sMQTTEvent

### Description
Constructor for the sMQTTEvent class.

### Parameters
#### Path Parameters
- **type** (unsigned char) - Description of the event type.
```

--------------------------------

### sMQTTSubUnSubClientEvent Constructors

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_sub_un_sub_client_event-members.html

Constructors for the sMQTTSubUnSubClientEvent class.

```APIDOC
## Client()

### Description
Constructor for sMQTTSubUnSubClientEvent.

### Method
`Client()`

### Parameters
None
```

```APIDOC
## sMQTTSubUnSubClientEvent(unsigned char type, sMQTTClient *client, const std::string &topic)

### Description
Constructor for sMQTTSubUnSubClientEvent.

### Method
`sMQTTSubUnSubClientEvent(unsigned char type, sMQTTClient *client, const std::string &topic)`

### Parameters
- **type** (unsigned char) - The type of the event.
- **client** (sMQTTClient *) - The client associated with the event.
- **topic** (const std::string &) - The topic associated with the event.
```

--------------------------------

### Handle All Broker Events with sMQTTBroker::onEvent

Source: https://context7.com/terrorsl/smqttbroker/llms.txt

Override this virtual method to process all significant broker events. Cast the `sMQTTEvent*` to the appropriate subclass. Return `false` from `NewClient_sMQTTEventType` to reject a connection.

```cpp
#include <sMQTTBroker.h>

class MyBroker : public sMQTTBroker {
public:
  bool onEvent(sMQTTEvent *event) override {
    switch (event->Type()) {

      case NewClient_sMQTTEventType: {
        auto *e = static_cast<sMQTTNewClientEvent*>(event);
        Serial.printf("Client connected: id=%s login=%s\n",
          e->Client()->getClientId().c_str(),
          e->Login().c_str());
        // Reject clients with wrong credentials
        if (e->Login() != "admin" || e->Password() != "secret") {
          return false; // deny connection
        }
        return true;   // allow connection
      }

      case RemoveClient_sMQTTEventType: {
        auto *e = static_cast<sMQTTRemoveClientEvent*>(event);
        Serial.printf("Client disconnected: id=%s\n",
          e->Client()->getClientId().c_str());
        break;
      }

      case Public_sMQTTEventType: {
        auto *e = static_cast<sMQTTPublicClientEvent*>(event);
        Serial.printf("Publish from %s  topic=%s  payload=%s\n",
          e->Client()->getClientId().c_str(),
          e->Topic().c_str(),
          e->Payload().c_str());
        break;
      }

      case Subscribe_sMQTTEventType: {
        auto *e = static_cast<sMQTTSubUnSubClientEvent*>(event);
        Serial.printf("Subscribe: client=%s topic=%s\n",
          e->Client()->getClientId().c_str(),
          e->Topic().c_str());
        break;
      }

      case UnSubscribe_sMQTTEventType: {
        auto *e = static_cast<sMQTTSubUnSubClientEvent*>(event);
        Serial.printf("Unsubscribe: client=%s topic=%s\n",
          e->Client()->getClientId().c_str(),
          e->Topic().c_str());
        break;
      }

      case LostConnect_sMQTTEventType: {
        Serial.println("Broker lost WiFi connection");
        break;
      }
    }
    return true;
  }
};

MyBroker broker;

void setup() {
  Serial.begin(115200);
  WiFi.begin("MySSID", "MyPassword");
  while (WiFi.status() != WL_CONNECTED) delay(500);
  broker.init(1883, true);
}

void loop() {
  broker.update();
}
```

--------------------------------

### update()

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/functions.html

Updates the sMQTTBroker. This is a class method.

```APIDOC
## update()

### Description
Updates the sMQTTBroker.

### Method
(Not specified)

### Endpoint
N/A

### Parameters
None explicitly documented.

### Request Example
N/A

### Response
N/A
```

--------------------------------

### ESP8266 Platform Definitions

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/s_m_q_t_tplatform_8h_source.html

Includes ESP8266 WiFi library and defines TCPClient and TCPServer to use WiFiClient and WiFiServer respectively. Conditional logging is enabled if DEBUG_ESP_PORT is defined.

```cpp
#elif defined(ESP8266)
#include <ESP8266WiFi.h>
#define TCPClient WiFiClient
#define TCPServer WiFiServer
#if defined(DEBUG_ESP_PORT)
#define SMQTT_LOGD(...) DEBUG_ESP_PORT.printf(__VA_ARGS__)
#else
#define SMQTT_LOGD(...)
#endif
```

--------------------------------

### sMQTTMessage::QoS

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_message-members.html

Returns the Quality of Service level of the message.

```APIDOC
## sMQTTMessage::QoS

### Description
Gets the Quality of Service level of the message.

### Method
`unsigned char QoS()`
```

--------------------------------

### sMQTTMessage::getString

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_message-members.html

Retrieves a string from a buffer.

```APIDOC
## sMQTTMessage::getString

### Description
Extracts a string from a given buffer.

### Method
`static const char* getString(const char *&buff, unsigned short &len)`
```

--------------------------------

### sMQTTEvent Class

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/s_m_q_t_t_event_8h_source.html

Base class for all MQTT events. It holds the type of the event.

```APIDOC
## sMQTTEvent

### Description
Base class for all MQTT events. It holds the type of the event.

### Methods
- **sMQTTEvent(unsigned char type)**: Constructor.
- **Type()**: Returns the type of the event.
```

--------------------------------

### sMQTTTopic Class

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/s_m_q_t_t_topic_8h_source.html

The sMQTTTopic class manages MQTT topics, including their names, payloads, QoS levels, and subscriptions.

```APIDOC
## Class sMQTTTopic

### Description
Represents a topic in the sMQTT broker, handling topic name, payload, Quality of Service (QoS), and managing subscribed clients.

### Methods

*   **sMQTTTopic(const char *name, char QoS=0)**: Constructor for creating a topic with a name and QoS.
*   **sMQTTTopic(const char *name, unsigned short nameLen, const char *payload, unsigned short payloadLen)**: Constructor for creating a topic with name, payload, and their lengths.
*   **sMQTTTopic(std::string &name, std::string &payload, char QoS=0)**: Constructor using std::string for name and payload.
*   **sMQTTTopic(sMQTTTopic *other)**: Copy constructor.
*   **~sMQTTTopic()**: Virtual destructor.
*   **update(sMQTTTopic *other)**: Updates the topic's payload and QoS from another topic.
*   **Name()**: Returns the topic's name.
*   **Payload()**: Returns the topic's payload.
*   **QoS()**: Returns the topic's QoS level.
*   **match(sMQTTTopic *other)**: Checks if this topic matches another topic.
*   **match(const std::string &other)**: Checks if this topic matches a given string.
*   **subscribe(sMQTTClient *client)**: Subscribes a client to this topic.
*   **unsubscribe(sMQTTClient *client)**: Unsubscribes a client from this topic. Returns true if the topic has no more subscribers.
*   **getSubscribeList()**: Returns a list of subscribed clients.

### Protected Members

*   **std::string _name**: The name of the topic.
*   **char *_payload**: Pointer to the topic's payload.
*   **unsigned char qos**: The Quality of Service level.
*   **unsigned short _payloadLen**: The length of the payload.
*   **sMQTTClientList clients**: A list of clients subscribed to this topic.
```

--------------------------------

### sMQTTMessage::add

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/classs_m_q_t_t_message-members.html

Adds data to the message. Overloaded for different data types like char, const char*, and std::string.

```APIDOC
## sMQTTMessage::add

### Description
Adds data to the message payload.

### Methods
- `void add(char byte)`
- `void add(const char *p, size_t len, bool addLength = true)`
- `void add(const std::string &str)`
```

--------------------------------

### onEvent()

Source: https://github.com/terrorsl/smqttbroker/blob/main/doc/html/functions_func.html

Processes incoming events for the sMQTTBroker.

```APIDOC
## onEvent()

### Description
Processes incoming events for the sMQTTBroker.

### Method
(Likely an event handler or callback)

### Parameters
None explicitly documented.

### Response
None explicitly documented.
```