Sending Transaction Request

Before sending any requests to the viaConex server, you will need the following Elavon-assigned credentials. These credentials should be sent in the header for all transaction requests.

  • Application_ID - 8 digit alpha-numeric value, provided by your Solution Engineer
  • Terminal_ID - 22 digit numeric value, provided by your Solution Engineer
  • Registration Key - NOVA_PORTAL_FAKE_KEY

The steps to successfully send a request to the viaConex server are in the following format:

  1. Open up a socket to

    The Production Host is

  2. Create a viaConex-formatted request message.


    Only use Elavon-approved (allowed) card account numbers to test your integration. Refer to Test Cards for a complete list of card account numbers that are allowed for Elavon’s test systems. Using card account numbers not allowed for Elavon’s test systems will return the INVALID CARD authorization response message.

  3. Send the request message as an HTTPS POST to the /cgi-bin/encompass4.cgi URL.

  4. Wait for the response to the submitted request.

  5. Parse the response sent back from Elavon.

    For multi-step transactions, such as Terminal-Based Settlements or Host-Based Echo messages, go back to step 2 and send the next transaction in the sequence. Repeat until the process is complete.

    For single-step transactions, the host will close the socket when complete.