Connecting AI to WhatsApp Business API — Lessons from 1000+ SME Deployments

We built HeyMag to connect AI assistants to WhatsApp Business numbers for SMEs across Southeast Asia. Here's what we learned. WhatsApp Business API Quirks The WhatsApp Business API has some non-obvious constraints that will trip you up if you're coming from building chatbots on other platforms: 24-hour messaging windows — you can only send free-form messages within 24 hours of the customer's last message. After that, you need pre-approved template messages. Template messages need pre-approval — Meta reviews every outbound template. Expect 24-48 hours for approval. Plan your flows around this. Media handling requires specific formatting — images, documents, and location pins each have their own payload structure. PDFs max out at 100MB. Rate limits scale with your quality rating — Meta assigns your number a quality rating based on user blocks and reports. Low quality = severe rate limits. What Actually Matters for AI Integration Building the AI part was the easier half. The hard part was