Pragma solidity ^0.8.0;

Contract subscription system {

Struct Paynive {

management sender;

Uint256 quantity;

Monitoring message;

}

}

Step 2: Create a service provider

Create an interface for your service provider and define subscription logic. This interface will be used to create events that cause payment processing.

Pragma solidity ^0.8.0;

Subscription of the Contractorvicevider {

Subscribe functions (user address) public phrases (bool) {

// impresses the logic to load the user every month

Requires (! User.subsssty: "The user is already subscribed");

User.subscripted = True;

return true;

}

Subscription disconnection function (user address) Public phrases (bool) {

// Implement the logic not to delay the user every month

User.subscripted = false;

return true;

}

}

Step 3: Create an event listener

Create an event listener that activates payment processing every month. This listener will be responsible for creating events and activating the logic of the subscription.

Pragma solidity ^0.8.0;

Payment contract of the listener {

Mapping (address => uint256) public payments;

Createpaytendent () Public Returns Function Payment (Bool) {

requires (msg.value> 0, "no payment is required");

payments [msg.sender] += msg.value;

return true;

}

}

Step 4: Integrate with blockchain

Integrate the listener of the Blockchain events using a library as web3.js or Solana Sdk. This will allow the creation and management of events, as well as the release of payments processing based on the "Createpaytendevent" function.

Import {Web3} with "@web3js/web3";

const web3 = new web3 ();

ASYNC processing function (event) {

// create a new event for subscription

Const paynivent = new paynivent ();

paynivent.sender = event.address;

paynivent.amount = 0;

paynivent.message = 'paid subscription';

// Call the subscription logic, causing the "subscription" function of the service provider

Wait subscription.

}

Examples of use

Here is an example of how you can use this implementation to create a simple subscription system: