A method of secure communication in mobile digital pages, comprising: receiving, by a data processing system comprising at least one processor, from a third party developer device, an electronic document configured to interface with a runtime application programming interface; validating, by the data processing system, the electronic document based on a validation policy; storing, by the data processing system, responsive to validation of the electronic document, the validated electronic document on a cache server of the data processing system; receiving, by the cache server from a viewer component executed by a client computing device, a request to access the electronic document; transmitting, responsive to the request, the electronic document from the cache server to the viewer component executed by the client computing device, the viewer component being configured to, in response to the transmitting of the electronic document: load, in an iframe, the electronic document for display via the client computing device; execute a runtime component to identify a tag coded with a markup language in the electronic document; and receive, from the runtime component via a secure communication channel, an indication of the tag; receiving, by the data processing system from the viewer component, the indication of the tag; selecting, by the data processing system based on the indication of the tag, a data value; transmitting, by the data processing system to the viewer component executed by the client computing device, the data value, the viewer component being configured to, in response to the transmitting of the data value: generate a prompt comprising the data value; receive, responsive to the prompt, input from the client computing device; and provide, via the secure communication channel and responsive to the input, the data value to the runtime component, the runtime component being configured to, in response to the providing of the data value, execute an action with the data value via the electronic document. receiving, by a data processing system comprising at least one processor, from a third party developer device, an electronic document configured to interface with a runtime application programming interface; validating, by the data processing system, the electronic document based on a validation policy; storing, by the data processing system, responsive to validation of the electronic document, the validated electronic document on a cache server of the data processing system; receiving, by the cache server from a viewer component executed by a client computing device, a request to access the electronic document; transmitting, responsive to the request, the electronic document from the cache server to the viewer component executed by the client computing device, the viewer component being configured to, in response to the transmitting of the electronic document: load, in an iframe, the electronic document for display via the client computing device; execute a runtime component to identify a tag coded with a markup language in the electronic document; and receive, from the runtime component via a secure communication channel, an indication of the tag; load, in an iframe, the electronic document for display via the client computing device; execute a runtime component to identify a tag coded with a markup language in the electronic document; and receive, from the runtime component via a secure communication channel, an indication of the tag; receiving, by the data processing system from the viewer component, the indication of the tag; selecting, by the data processing system based on the indication of the tag, a data value; transmitting, by the data processing system to the viewer component executed by the client computing device, the data value, the viewer component being configured to, in response to the transmitting of the data value: generate a prompt comprising the data value; receive, responsive to the prompt, input from the client computing device; and provide, via the secure communication channel and responsive to the input, the data value to the runtime component, the runtime component being configured to, in response to the providing of the data value, execute an action with the data value via the electronic document. generate a prompt comprising the data value; receive, responsive to the prompt, input from the client computing device; and provide, via the secure communication channel and responsive to the input, the data value to the runtime component, the runtime component being configured to, in response to the providing of the data value, execute an action with the data value via the electronic document.