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Via the Voice Api of sms77 you can issue calls to certain phone numbers. The simplest way is to specify a text which is read to the recipient via our Text-to-Speech Gateway. For advanced applications, you have the option of sending the text in XML format. For this use our markup language VoiceML77 (more soon).

Please use the following URL for your request:


In addition to authentication, the following parameters are required:

Required parameters

ParameterDescriptionPossible values
toRecipient number
Allowed are numbers and address entries (contacts only). Currently just one recipient per call is possible.
textText message to be read or XML dataMax 10,000 characters

Optional parameters

ParameterDescriptionPossible values
xmlSpecifies whether the text variable is a plain text to be read, or an XML format.1 = XML
0 = text (default)
fromCaller ID. Please use only verified sender IDs, one of your virtual inbound numbers or one of our shared virtual numbers.491771783130



The phone number +49171999999999 is called and This text is read. is announced on the phone.

Our Voice Gateway can be expanded individually – e.g. with interactive menus, MP3s can be played and much more. Contact us for your specific requirements!


Setup a webhook in your account settings to receive realtime status updates of your call.

We will send the following parameters to your callback URL:

idID of the Voice Call
callerIdSent caller ID
recipientRecipient number
statusCurrent status of the call.

Possible values are: completed, no-answer, failed, initiated, ringing, in-progress

durationYou will get the duration of the call in seconds when it is completed.
pricePerMinutePrice per minute in Euro.
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