3. MESSAGE HANDLING
3.1
Message Exchange Mode
GePG APIs make use of asynchronous and synchronous modes of communication to
complete requests processing. In asynchronous mode, GePG will receive requests
from clients and acknowledge in the same session call. Later after request
processing, GePG will call back clients system with request processing results at a
callback url provided by client. In synchronous mode, GePG will receive requests,
process them and return processing results in the same session call.
It is highly recommended for clients’ systems to acknowledge to GePG callback
requests immediately and proceed with other internal processing later.
3.2
Protocol (HTTP/HTTPS)
GePG APIs implements REST API Web Service where all requests will be received
through http or https POST method.
3.3
Message Acknowledgment and Response
In every message exchange between GePG and Institution System, message will be
acknowledged and/or responded according to each API specification.
Acknowledgement and response from GePG shall have at least one GePG response
code and its description. If there are multiple GePG response codes; contents will be
separated by semicolon (;). Institution system acknowledgement or response shall
contain one of the response codes. On receipt of the mentioned response code, GePG
shall perform appropriate action as per received response code. Otherwise receipt of
any other status code, GePG will assume message was received and processed
successfully.
3.4Retry Mechanism
3.4.1Institution to GePG
Every API request from Institutions’ systems to GePG will be acknowledged as per
API specification. If an Institution does not receive request acknowledgement from
GePG, Institution system has to retry sending an unacknowledged request provided
that communication channel between the systems is working as agreed.
3.4.2
GePG to Institution
Either, GePG is going to follow the following guidelines to handle retry:-
a) No communication to Institution System
GePG will keep messages in waiting state, check for connectivity once in
every hour and resume sending to destination system once connectivity is