[FEATURE]: Add WhatsApp Integration Node

[amaan1114]

Feature Summary

Add a WhatsApp integration node that enables workflows to send WhatsApp messages using the WhatsApp Business Cloud API. This will allow users to automate notifications, alerts, and customer communications directly from AsyncNode workflows.

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Problem Statement

AsyncNode currently supports workflow automation across multiple services, but there is no built-in integration for WhatsApp messaging.

Many automation workflows require sending notifications through WhatsApp for use cases such as:

• Customer notifications
• Order updates
• Appointment reminders
• OTP delivery
• Internal team alerts
• Automated support messages

Without a dedicated WhatsApp node, users cannot include WhatsApp messaging as part of their workflow automations.

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Proposed Solution

Implement a new WhatsApp integration node following the existing integration architecture.

The implementation should include:

• WhatsApp Business Cloud API integration
• Secure credential configuration and storage
• Connection validation
• Workflow node configuration UI
• Backend executor for sending messages
• Proper error handling and retry support
• Documentation for setup and usage

The node should integrate seamlessly with the existing workflow builder and execution engine.

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Benefits

• Expands AsyncNode's integration ecosystem.
• Enables real-world notification and messaging workflows.
• Improves automation capabilities for businesses and developers.
• Provides a foundation for future WhatsApp features such as media messages and interactive templates.

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Additional Context

• The implementation should follow the existing integration architecture used throughout AsyncNode.
• Credentials must be stored securely using the project's existing credential management system.
• Contributors should use the official WhatsApp Business Cloud API where applicable.
• Existing workflow execution and logging mechanisms should remain compatible with the new integration.