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]
The Server MUST reply with the same value in the Response object if included. This member is used to correlate the context between the two objects.
[1] The use of Null as a value for the id member in a Request object is discouraged, because this specification uses a value of Null for Responses with an unknown id. Also, because JSON-RPC 1.0 uses an id value of Null for Notifications this could cause confusion in handling.
[2] Fractional parts may be problematic, since many decimal fractions cannot be represented exactly as binary fractions.
JSON RPC Request Id
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]
The Server MUST reply with the same value in the Response object if included. This member is used to correlate the context between the two objects.
[1] The use of Null as a value for the id member in a Request object is discouraged, because this specification uses a value of Null for Responses with an unknown id. Also, because JSON-RPC 1.0 uses an id value of Null for Notifications this could cause confusion in handling.
[2] Fractional parts may be problematic, since many decimal fractions cannot be represented exactly as binary fractions.