# Microsoft .NET Core APIs

The Microsoft .NET Core APIs provide the client-side .NET interfaces to set up connection with the server, package or unpackage requests and responses in XML format, query any API on the server, determine the queried result, and so on.

The Microsoft .NET Core APIs provide the following information:

- Microsoft .NET classes

- NaServer—This class provides the methods to set up server connection and session parameters, send any API to the server, parse the API response, and so on.

- NaElement—This class encapsulates the input output (I/O) elements. An NaElement class encapsulates one level of an I/O element. You can nest these I/O elements arbitrarily. They have names, corresponding to the XML tags, attributes (only used for results), values (always Strings), and children, corresponding to the nested tagged items. The methods of this class are used to package the requests and responses, create new elements, change the contents of the elements, and so on.

- Exceptions

- NaException—This is the base class for all the ONTAPI exceptions. It is thrown when there is a problem in invoking an API.

- NaApiFailedException—This exception indicates a failed API invocation. The server processes the request and returns a result that includs an error number and a reason for failure in string format.

- NaAuthException—This exception is thrown when the remote server does not accept the credentials provided with the request, or when the required credentials are missing.

- NaConnectionException—This exception is thrown when there is an error connecting to the remote server.

- NaProtocolException—This exception is thrown when the response of the remote server is not known.

- Enumerations

- ErrNo—This enumeration provides the error code constants.

## Content of this section

This section provides API information for the Microsoft .NET Core APIs. It includes the following classes, exceptions, and enumerations.

- NaServer

- NaElement

- NaException

- NaAPIFailedException

- NaAuthException

- NaConnectionException

- ErrNo

Related Topic

- Library Information