How to Build a WhatsApp Chatbot

Cloud API, message templates, the 24-hour window - the architecture that automates WhatsApp support at scale.

WhatsApp is the highest-intent channel most businesses ignore because the rules look intimidating. Message templates, opt-in, the 24-hour session window, and a verified Business account all gate what you can send. This guide covers the build that respects Meta rules and still automates the bulk of inbound conversations.

No fluff. Real conversational AI from engineers who ship bots that hold up in production.

What Makes a WhatsApp Chatbot Different from a Web Chatbot?

WhatsApp is not just another chat widget. Meta enforces a strict messaging model: outside a 24-hour window opened by the user message, you can only send pre-approved message templates, and every contact must opt in. Ignore this and your number gets rate-limited or banned. The rule: design around the 24-hour customer service window and template categories from the start. The conversation model is a compliance constraint, not an afterthought - it shapes your entire automation flow.

At Valletta Software, we focus on:

WhatsApp Business Platform: Cloud API hosted by Meta - no server for messaging infra - or on-premise via a BSP

Opt-in: collect explicit consent before messaging - store proof - required by Meta policy

24-hour window: free-form replies only within 24h of the user last message - templates outside it

Message templates: pre-approved by Meta by category - utility marketing authentication - 1-2 day review

Phone number: verified WhatsApp Business number with display name - quality rating affects send limits

Webhooks: receive inbound messages and status events - respond within the window programmatically

Fallback: hand off to a human agent in a shared inbox when the bot cannot resolve - within the window

What Does It Take to Ship a Compliant WhatsApp Bot?

The technical build is straightforward. The compliance and template design are what decide whether you stay live.

We give you more than just people. We give you top performers who drive results.

Cloud API setup: Meta Business verification - WhatsApp Business Account - phone number registration

Template library: design utility and authentication templates - submit for approval before launch

Conversation engine: LLM or flow-based logic that respects the 24-hour window and template rules

Opt-in flow: capture and store consent - with an easy opt-out keyword like STOP

CRM sync: log every conversation against the contact in HubSpot or Salesforce

Agent handoff: route to a shared team inbox when the bot escalates - within the window

Monitoring: track quality rating template approval status delivery and read rates

You lead the work. We handle the rest. From EUR 45/h.

EU-incorporated in Malta - NDA on day one, full GDPR compliance. Trusted by startups and enterprise teams across 12+ industries.

Build conversation logic that respects the 24-hour window

Design and submit Meta-approved message templates

Integrate the Cloud API webhooks and CRM sync

Monitor quality rating and delivery before it hits limits

How to Build a WhatsApp Chatbot - With Engineers Who Know Meta Rules

Lets keep it simple.

Our engineers use AI for the conversation logic and handle the parts that get accounts banned - template approval, opt-in compliance, and window management - so your number stays healthy and your automation stays live.

Choose from a solo dev, mini team, or full squad. All powered by AI and ready to build from day one.

Lets keep it simple.

Our engineers set up the WhatsApp Business Platform correctly the first time - verification, templates, opt-in, and window handling - so you automate support without risking the number.

How we work