Why are Sirena’s sessions used?

The WhatsApp Business API service brings countless benefits to businesses. Among them, the main one, is that the API allows several users to use the same WhatsApp line.

When you use Sirena you are using the official WhatsApp API. As the API is commonly used by companies that can generate thousands of interactions, WhatsApp placed certain rules to prevent misuse of the application.

One of those rules is that to start a conversation you must use message templates pre-approved by WhatsApp,which generate a cost when sent.

To structure this rule, WhatsApp created the concept of "Session". As this is a WhatsApp rule, everyone who is authorized to use the API, including our competitors, charges for sending the templates needed to log in.

What is a "Session" for WhatsApp?

It is a 24-hour period that opens with an incoming message from the client. Every time you receive a message, those 24 hours are extended.

When you don't receive a message from the customer for 24 hours, you can no longer send them messages again, unless you use a WhatsApp Preapproved Template.

In the pricing section of our website, you will be able to see the costs of these templates.

It is important to be clear that it is not charged per message, it is done per logged in with a template. Each template submitted has a cost.

For example, if two templates are sent and the customer responds the second within 24 hours, two conversation starts are charged by the business (there were two attempts, one with each template).


In the event that a template is submitted and the customer responds after 24 hours, two costs are charged:

  1. That of the business-initiated conversation attempt (pre-approved template).

  2. That of the conversation initiated by the client, for becoming effective more than 24 hours after the attempt of the business.

During a session you can exchange the messages you want, the only limit is that 24 hours do not pass without a message from the client or without you having sent a pre-approved template.

For each country there is a variable cost to start a session. This cost depends on the country in which your company has a legal presence, according to what you reported when you subscribed to Sirena.

In the case of this particular country, the price per conversation initiated by the customer is 0.01 USD, while if you start it with a template it will more than double, 0.0266.

That is, to avoid spam, WhatsApp sets a higher cost for templates started by your company.

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