In one embodiment, the present invention is a transaction gateway apparatus for effecting a transaction request, the apparatus being configured to receive transaction request data, select, based on said transaction request data, one of a plurality of workflows to be performed that defines transaction data route between said apparatus and a transaction service provider specified in said workflow, wherein said apparatus is configured to: display a user interface defining a workspace within which a user can configure a workflow; access a plurality of modules, each defining respective service provider functions, a plurality of rule sets defining conditions to be fulfilled for a transaction data route to follow a specified path of a workflow; display selectable data representative of said modules and rule sets in said work space; enable a user to configure a visual representation of a workflow by: selecting a transaction type or parameter to be associated with a workflow; selecting combinations of one or more modules and rule sets to be included in said workflow, said apparatus being configured to display said selected combination in said work space; selectively defining visual links between said modules and/or rule sets to define respective workflow paths; and convert a user-configured workflow to an executable transaction data route for execution in the event that transaction request data received by said apparatus is determined thereby to match a transaction type or parameter associated with said workflow.