A network apparatus comprising at least one processor and memory, the memory (44, 46, 82, 93) storing executable instructions that, when executed by the at least one processor (32, 91, 81), implement a service of a communications network, the service supporting service capabilities through a set of Application Programming Interfaces,APIs, the service being located in a protocol layer between applications and application protocol layers to enable multiple applications to interact with the service, and cause the service to perform operations comprising: storing, in the memory of the network apparatus, one or more message templates that can be manipulated in a RESTful manner in the protocol layer of the service, each message template comprising one or more values of parameters associated with a respective type of message that may be received by the service from one or more devices on the communications network, each message template having a list of target resources identifying one or more target resources of the apparatus that the message template applies to, wherein the one or more target resources are uniquely addressable element in the protocol layer of the service according to a Resource Oriented Architecture, ROA; receiving, a request to create a new request message template, the request to create a new request message template comprising one or more values of parameters associated with a respective type of message which the message template is to represent and one or more target resources that the message template applies to; creating a new request message template, the new request message template comprising corresponding parameter values, wherein the corresponding parameter values are the received parameter values; generating an identifier associated with the new request message template; storing, in the memory, the new request message template in association with its identifier and its target resources; receiving, from the device on the communications network, a message targeting a resource of the apparatus matching a target resource of the message template; retrieving, from the memory in response to the message from the device, a stored message template associated with the resource targeted in the message received from the device; combining the information in the received message with the parameter values in the retrieved message template to form a complete message; processing the complete message; and sending, to the device in response to the message received from the device, a response message. storing, in the memory of the network apparatus, one or more message templates that can be manipulated in a RESTful manner in the protocol layer of the service, each message template comprising one or more values of parameters associated with a respective type of message that may be received by the service from one or more devices on the communications network, each message template having a list of target resources identifying one or more target resources of the apparatus that the message template applies to, wherein the one or more target resources are uniquely addressable element in the protocol layer of the service according to a Resource Oriented Architecture, ROA; receiving, a request to create a new request message template, the request to create a new request message template comprising one or more values of parameters associated with a respective type of message which the message template is to represent and one or more target resources that the message template applies to; creating a new request message template, the new request message template comprising corresponding parameter values, wherein the corresponding parameter values are the received parameter values; generating an identifier associated with the new request message template; storing, in the memory, the new request message template in association with its identifier and its target resources; receiving, from the device on the communications network, a message targeting a resource of the apparatus matching a target resource of the message template; retrieving, from the memory in response to the message from the device, a stored message template associated with the resource targeted in the message received from the device; combining the information in the received message with the parameter values in the retrieved message template to form a complete message; processing the complete message; and sending, to the device in response to the message received from the device, a response message.