For communicating with NIC servers you must use EPP. Here is a brief start point for you!
EPP (Extensible Provision Protocol) defines an unified way how registrars can communicate with registries of domain names by exchanging XML messages.
EPP is typically implemented as an API between the registrar’s web interface and the Registry. Such integration allows registrar to react immediately to requests from it’s clients and know for sure if the action succeeded or not. Should some action, such as registration of a domain name, to be put off until later, the registry will notify registrar with the service message.
What benefits are from using EPP?
- Once a client software is implemented, it becomes more easy to integrate it with other registries and offer a wider range of top-level domain names to your clients.
- Requests from your clients can be performed automatically and 24/7
- A typical EPP conversation starts when client connects to the server using SSL.
- Server responds with a “service menu” with offered services and extensions available languages etc.
- Client logs in using it’s account name and password and chooses services and other options for conversation from the offered ones.
- Client polls the server for unread notifications and retrieves them if any.
- Client reads details, creates new or updates existing contact persons, domain names and associated networks as needed. Server responds immediately with a well defined response code, reflecting the status of requested object.
- Client waits for new things to be done, periodically polling for notification messages to keep session alive.
- Connection is ended either by client when all is said and done or by the server if session timeouts.
EPP protocol describes both synschronous and asynchronous operation modes, But most of NICs offer EPP service only in synchonous mode (client receives answer for each request and only then sends next command to the server).
Here is a more detailed documentation.