Receive notification of a newly-received fax via callback to your web app

You can select to receive inbound fax notifications directly to your system by callback. When this feature is set, InterFAX places a call to a pre-defined web application URL of yours once a fax is received for you. Your web application should be capable of accepting either an HTTP POST call or a XML Web Service (SOAP) call – based on your preference. Once your app is alerted of an incoming fax, you need to collect the fax image by using the API.

You can also set the system to send you feedback notifications on outbound faxes. For more information, please read the outbound callback documentation.

Preparatory steps

HTTP POST callback

To receive HTTP POST callbacks to a simple script on your server, no preparation is necessary. Skip to “Setting up the callback” below.

SOAP callback

To receive callbacks to a SOAP server, perform these setup steps:

  1. Set up a web application that is capable of accepting callbacks on your server.
    • If you set up a SOAP server, its namespace should be (namespace is case sensitive, this is the expected WSDL).
  2. The web application should contain a web method named “Inbound”.
  3. The web method should return a string -> “OK”.

Setting up the callback

Login to your InterFAX account and go to Preferences -> Incoming. Find and set the following settings under Advanced Options:

Selection Description Possible Values
Web Feedback Method What type of callback does your web application expect NeverXML Web Serviceor HTTP POST
Web Feedback URL The URL to your web application. Any valid web address (*)

(*) please note, InterFAX only supports URLs using standard port 443.

Callback contents

Once Web Feedback is set up, the InterFAX system will call back your web app by HTTP POST or by XML Web Service and provide the following structure:

Parameter Name Parameter Type Description
TransactionIDType String The type of message. Currently sends out static ‘Inbound’
TransactionID Integer The ID of this transaction
PhoneNumber String The Phone number at which this fax was received
MessageType Integer The type of message. Currently sends out static ‘1’.
MessageSize Integer The size of the inbound fax image (in bytes)
RemoteCSID String The CSID of the sender
Pages Integer The number of pages received in this fax.
Status Integer Status of the fax. See the list of InterFAX Error Codes
RecordingDuration Integer The time (in seconds) that it took to receive the fax
ReceiveTime DateTime The time and date that the fax was received in GMT timezone.
When returned via HTTP POST: m/d/yyyy h:mm:ss tt.
When returned via Web Service: ISO-8601 compliant.
CallerID String The caller ID of the sender

Once your application has received notification that a new fax has arrived, it needs to collect the fax image from InterFAX servers using the API of your choice. You may also mark your fax as read via the API, but this isn’t compulsory.

This process is detailed in the following diagram.