WhatsApp Bulk Messaging Tool

I need a lightweight application that lets me fire off large batches of WhatsApp messages without violating the platform’s limits. The core requirement is true bulk-send capability: I type or paste numbers directly into the tool, hit send, and the software handles the rest—queueing, throttling, and reporting delivery status.

Because I will be entering contacts manually, the interface has to make that quick and painless. A simple text box that accepts comma-separated numbers, plus basic validation for country codes, is fine. Once stored, I want to be able to search and filter those contacts instantly so I can reuse or refine the list for the next campaign.

Key deliverables:
• Desktop or web-based app (your choice, just specify).
• Manual number entry with automatic duplicate removal and basic phone-number validation.
• Fast bulk-send engine with progress display and success/fail log export.
• Contact search and filter functions that work in real time.
• Clean, intuitive UI and clear setup instructions.

If you’ve already worked with WhatsApp’s underlying protocols or cloud APIs and know how to stay compliant, that’s a big plus. Please outline your proposed tech stack, estimated timeline, and any constraints I should be aware of.