diff --git a/README.md b/README.md
index b054aa9..22eadca 100644
--- a/README.md
+++ b/README.md
@@ -54,6 +54,14 @@ export NVOIP_TARGET_NUMBER="11999999999"
 - `ruby examples/list_whatsapp_templates.rb`
 - `ruby examples/send_whatsapp_template.rb`
 
+### Destinatário WhatsApp
+
+O exemplo mantém `NVOIP_WA_DESTINATION` para telefone. Para o contrato tipado,
+use `NVOIP_WA_RECIPIENT_TYPE=phone|bsuid|parent_bsuid` e
+`NVOIP_WA_RECIPIENT_VALUE`, sem `destination`. BSUID é opaco; não use
+`@username` nem o coloque em campo de telefone. Exemplos mascarados:
+`US.MASKED_BSUID_001` e `PARENT.MASKED_BSUID_001`.
+
 ## SDK web
 
 Para o fluxo de popup com telefone e código, use em conjunto o repositório `nvoip-web-sdk`. Este repo cobre o consumo server-side da API.
diff --git a/examples/send_whatsapp_template.rb b/examples/send_whatsapp_template.rb
index 1d22282..2631d78 100644
--- a/examples/send_whatsapp_template.rb
+++ b/examples/send_whatsapp_template.rb
@@ -9,15 +9,37 @@
 
 payload = {
   idTemplate: ENV.fetch("NVOIP_WA_TEMPLATE_ID"),
-  destination: ENV.fetch("NVOIP_WA_DESTINATION", ENV.fetch("NVOIP_TARGET_NUMBER", "11999999999")),
   instance: ENV.fetch("NVOIP_WA_INSTANCE"),
   language: ENV.fetch("NVOIP_WA_LANGUAGE", "pt_BR")
 }
 
+recipient_type = ENV.fetch("NVOIP_WA_RECIPIENT_TYPE", "").strip.downcase
+recipient_value = ENV.fetch("NVOIP_WA_RECIPIENT_VALUE", "").strip
+if recipient_type.empty?
+  destination = ENV.fetch("NVOIP_WA_DESTINATION", ENV.fetch("NVOIP_TARGET_NUMBER", ""))
+  raise "NVOIP_WA_DESTINATION must be a phone number; use recipient for BSUID" unless destination.match?(/\A\+?\d{8,20}\z/)
+  payload[:destination] = destination
+else
+  unless %w[phone bsuid parent_bsuid].include?(recipient_type) && !recipient_value.empty?
+    raise "NVOIP_WA_RECIPIENT_TYPE must be phone, bsuid or parent_bsuid and requires NVOIP_WA_RECIPIENT_VALUE"
+  end
+  raise "@username is not a WhatsApp recipient; use a BSUID or parent BSUID" if recipient_value.start_with?("@")
+  if recipient_type == "phone" && !recipient_value.match?(/\A\+?\d{8,20}\z/)
+    raise "A phone recipient must contain only an optional leading + and 8 to 20 digits"
+  end
+  if recipient_type != "phone" && (recipient_value.match?(/\s/) || recipient_value.length > 256)
+    raise "A BSUID must be an opaque value without whitespace (maximum 256 characters)"
+  end
+  payload[:recipient] = { type: recipient_type, value: recipient_value }
+end
+
 body_variables = JSON.parse(ENV.fetch("NVOIP_WA_BODY_VARIABLES", "[]"))
 header_variables = JSON.parse(ENV.fetch("NVOIP_WA_HEADER_VARIABLES", "[]"))
 payload[:bodyVariables] = body_variables unless body_variables.empty?
 payload[:headerVariables] = header_variables unless header_variables.empty?
-payload[:functions] = { to_flow: true } if ENV.fetch("NVOIP_WA_TO_FLOW", "false").downcase == "true"
+if ENV.fetch("NVOIP_WA_TO_FLOW", "false").downcase == "true"
+  raise "WhatsApp Flow and attendance require a phone recipient" if %w[bsuid parent_bsuid].include?(recipient_type)
+  payload[:functions] = { to_flow: true }
+end
 
 puts JSON.pretty_generate(client.send_whatsapp_template(payload: payload, access_token: oauth.fetch("access_token")))