Type alias JSONRPCRequestMessage<T>

JSONRPCRequestMessage<T>: {
    id: string | number | null;
    jsonrpc: "2.0";
    method: string;
    params?: T;
}

This is the JSON RPC request object. this is the generic message type used for the RPC.

id: string | number | null

An identifier established by the Client that MUST contain a String, Number, or NULL value if included. If it is not included it is assumed to be a notification. The value SHOULD normally not be Null [1] and Numbers SHOULD NOT contain fractional parts [2]
jsonrpc: "2.0"

A String specifying the version of the JSON-RPC protocol. MUST be exactly "2.0"
method: string

A String containing the name of the method to be invoked. Method names that begin with the word rpc followed by a period character (U+002E or ASCII 46) are reserved for rpc-internal methods and extensions and MUST NOT be used for anything else.
Optional params?: T

A Structured value that holds the parameter values to be used during the invocation of the method. This member MAY be omitted.