API

class cassiamqtt.CassiaMQTTClient

Establishes a connection with the MQTT Broker to publish and subscribe to messages. Currently, up to two instances are supported.

__init__(self, uri, username: str | None = None, password: str | None = None, client_id: str | None = None) → CassiaMQTTClient

Returns itself after initializing parameters.

Parameters:

• uri: MQTT Broker URI

• username: Username

• password: Password

• client_id: Client ID

async __aenter__(self)

Establishes a connection and allocates resources.

async __aexit__(self)

Disconnects and releases resources.

async __aiter__() → BLEScanResult

Returns itself, allowing the instance to be used directly in an async for loop.

async __anext__() → dict

Returns the subscribed message.

When the queue is empty, it will wait until new data arrives. The iteration terminates when the connection is disconnected.

Data Field Description

Field	Type	Description	Example
topic	str	Topic	/dev/down/CC:1B:E0:E4:C8:94/api
qos	int	QoS	0
payload	str	Payload	{“id”:”1758…

async publish(self, topic: str, payload: str, qos: int = 0, retain: bool = False) → tuple[ok: bool, result: str]

Publishes a message to the specified topic.

Parameters:

• topic: Topic

• payload: Payload

• qos: QoS

• retain: Indicates whether the message should be retained.

Returns:

• ok: Whether the execution was successful

• result: Execution result

async subscribe(self, topic: str, qos: int = 0) → tuple[ok: bool, result: str]

Subscribes to messages from the specified topic.

Parameters:

• topic: Topic

• qos: QoS

Returns:

• ok: Whether the execution was successful

• result: Execution result

async unsubscribe(self, topic: str) → tuple[ok: bool, result: str]

Unsubscribes from messages of the specified topic.

Parameters:

• topic: Topic

Returns:

• ok: Whether the execution was successful

• result: Execution result