The WhatsApp Business API, explained simply
What it is, how it differs from the WhatsApp apps, when you need a template, how the 24-hour window and the free ad window work, and what Meta charges for each message.
Your WhatsApp number, connected to your business software
With the API, your WhatsApp number isn’t tied to one phone. Messages flow through Meta’s Business API into software like WhatsRay, where your whole team works from one shared inbox.
One number, many agents
Everyone replies from the same number at once, each with their own sign-in.
Shared inbox
Assign chats, add notes and labels, and see each customer’s full history.
Automation and chatbots
Welcome messages, flows and AI bots answer common questions for you.
Campaigns and updates
Send approved templates to many customers: offers, order and payment updates, codes.
WhatsApp Business app vs the Business API
The app is great for one person replying on one phone. The API is for a business that has a team, many chats and things to automate.
| WhatsApp Business app | Business API with WhatsRay | |
|---|---|---|
| Who replies | One phone, a few linked devices | Your whole team, from a web inbox |
| Automation | Greeting and away messages | Flows, AI bots, welcome messages, saved replies |
| Messaging many customers | Broadcast lists, limited | Campaigns with approved templates and reports |
| Starting a conversation | Any message | An approved template |
| Customer history | On the phone | Contacts, labels, notes, statuses |
| Connect your systems | No | API, website chat button, WooCommerce |
| Meta charges | None | Per message, by type (see below) |
You can’t start a conversation with a normal message
On the API, when your business messages a customer first, it must be an approved template. This reduces spam and protects customers from messages they didn’t ask for.
A template is a message you write once and submit to Meta for approval. It can include the customer’s name, an order number or a date, and buttons.
Three template categories
Offers, promotions and discounts.
About something the customer did: orders, payments, appointments.
One-time passwords and verification codes.
When you can send normal messages
A normal message is any reply that isn’t a template: text, photos, documents, voice notes. You can send them only while the customer’s 24-hour window is open.
- The customer messages youWhether they write first or reply to your template, a 24-hour window opens.
- Every customer message resets the clockThe 24 hours always count from their latest message.
- Inside the windowReply with normal messages; no template needed.
- The window closes24 hours after their last message, normal messages are blocked.
- Reopen it with a templateSend an approved template. When the customer replies, a new 24-hour window opens.
The free ad window
When a customer messages you from a Click-to-WhatsApp ad on Facebook or Instagram, using WhatsApp on their phone, and you reply within 24 hours, Meta opens a free window that can last up to 7 days, counted from your reply. Everything you send while it’s open is free. The inbox shows when it ends.
While the window is open
- Normal replies, including your AI bot’s, cost nothing.
- Utility, authentication and even marketing templates sent to that customer are free.
- The 24-hour window still decides what you can send: if the customer goes quiet for 24 hours, you can only send templates, but while the free window is open those are free too.
- If you miss the first 24 hours, there’s no free window: normal pricing applies from the start.
If the customer keeps chatting after the window ends
- It’s an ordinary chat again: each customer message opens or extends a normal 24-hour window.
- Your replies are service messages: they use your 1,000 free a month, then are charged.
- Utility templates are charged, and once the 24-hour window closes you need a template to reach them.
Meta’s own AI agent (Meta Business Agent) is charged by Meta even inside the free window; replies from WhatsRay’s AI bots are normal messages and are free there.
What Meta charges now
The 24-hour window still works the same way. What changed is which messages are free.
- Normal service messages in the windowFree
- Utility templates inside the windowFree
- Marketing templatesPaid
- Authentication templatesPaid
- Normal service messages1,000 free / month
- Utility templates, even inside the windowPaid
- Marketing templatesPaid
- Authentication templatesPaid
1,000 free per month, per WhatsApp number
Normal replies inside the window are still allowed. But only the first 1,000 service messages each month on each WhatsApp Business number are free. After that, every service message is charged.
Messages 1 – 1,000: free · from 1,001: per-message chargeCharged even inside the 24-hour window
Payment, order and appointment updates sent as utility templates used to be free while the window was open. Now the utility rate applies every time.
Every message counts, so reply smarter
Each separate message you send is one service message. Four short replies use four of your free 1,000; one complete reply uses one.
What each message costs, in rupees
Sri Lanka has its own rates on Meta’s rate card, charged in US dollars. Rupees below are approximate, at Rs. 330 per US dollar.
Marketing costs far more than the other types: 1,000 marketing messages are about Rs. 24,160. See all rates and work out your cost
“The window is open, so everything is free.”
The window gives you permission to send normal messages. It doesn’t make them free.
- Can I send a normal message? Only while the window is open.
- How much will it cost? Depends on the message type and, for service messages, whether you’re past 1,000 this month.
Don’t just ask how many messages. Ask what type.
Enter roughly how many messages of each type you send in a month on one WhatsApp number. Rates are approximate and you can change them.
Example above: 3,000 service, 2,000 utility, 500 authentication and 1,000 marketing messages come to about Rs. 27,100, and marketing is the biggest part.
Your total WhatsApp cost with WhatsRay
Two parts. WhatsRay is the software that connects your number to the API, so there’s no separate connection fee.
Stay with the WhatsApp Business app if
- One person answers every customer.
- You don’t need automation or campaigns.
- Managing everything on one phone works for you.
Move to the Business API with WhatsRay if
- More than one person replies to customers.
- You want flows, AI bots, templates or campaigns.
- You need customer history, labels, reports or API access.
Rupee figures are approximate. Meta’s pricing and exchange rates may change; check the current rate card before planning large sends.