WhatsApp Business API: the complete guide.

What is the WhatsApp Business API?

The WhatsApp Business API, also called the WhatsApp Business Platform or Cloud API, is Meta's official way for businesses to message customers from software instead of a phone. It is different from the free WhatsApp Business app.

With the app, one phone holds every chat. With the API, your whole team works from one verified number in a shared inbox, AI agents answer automatically, and your systems can send order updates, reminders and one-time passwords on their own.

Who needs it?

You are ready for the API when any of these is true:

• More than one person needs to answer customers on the same number.
• Customers message outside office hours and wait until morning for a reply.
• You send order, delivery, appointment or payment updates by hand.
• You want to send campaigns to customers without risking your number.
• Your website, store or CRM should send WhatsApp messages automatically.

What you need to apply

• A business registration certificate and proof of business address.
• Admin access to your Meta Business Manager (we can help you create one).
• A phone number that is not active on WhatsApp or the WhatsApp Business app.
• A live website, and a business email on the same domain.
• Your brand details: display name, logo, description and category.
• A debit or credit card for Meta's message fees.

Setup, step by step

1. Onboarding. We create your Unecast workspace, connect your Meta Business Manager through Meta's Embedded Signup and register your number.
2. Business verification. Your documents go to Meta for review. This usually takes 1 to 10 days and is the only step on Meta's timeline.
3. Profile and templates. We set up your business profile and draft your first message templates for Meta approval.
4. Team and AI agent. Every staff member gets a login by role, and your AI agent learns your FAQs, prices and policies.
5. Go live. Training for agents and managers, then live dashboards to watch quality and costs.

What it costs

There are two parts: your provider's platform fee and Meta's per-message fees.

Platform fee (Unecast)

Starter $29, Growth $49 and Scale $99 a month, with optional guided onboarding quoted to your project. The AI agent is optional: build it yourself, or have us build it, then about $0.002 to $0.015 per AI reply. Billing in Sri Lankan rupees is also available. See full pricing.

Meta fees

Meta charges per template message, by category, and bills your card directly. Unecast adds no markup. Pick the country you send to. Rates are what Meta charges per delivered message, in US dollars, taken from Meta's official rate card.

Country you message Sri Lanka

Rates from Meta's official rate card.

Meta updates its rate card periodically. Check Meta's current rates before budgeting.

Messaging rules to know

• The 24-hour window. When a customer messages you, you can reply freely for 24 hours. After that, you need an approved template.
• Opt-in. Business-initiated messages need the customer's permission, and marketing messages must let them opt out.
• Quality rating. Meta rates your number from customer feedback. Blocks and reports lower it and can limit sending, so target the right people with useful messages.
• Categories are checked. A promotion submitted as a utility template will be recategorised as marketing.

Languages

Meta supports templates in dozens of languages, including English, Spanish, Arabic, Hindi, Sinhala and Tamil, and free-form replies can be in any language. Unecast AI agents reply in the language each customer writes in. SMS supports many languages too.

Common mistakes that slow businesses down

• Using a number that is still active on a phone. Remove it from the app first.
• A website that does not show the business name, address or contact details Meta can match.
• An email address on a free domain instead of your business domain.
• Starting with marketing broadcasts to cold lists, which lowers quality rating fast.
• Choosing an unofficial tool that automates the normal WhatsApp app, which risks a ban.

Frequently asked questions