Where to check for node value constraints on services data receive I have a REST service to create nodes. On data receive, node.create is executed, but before actually creating the node I need to check some constraints like node type and other node values. 

Is there any I can use?
To have more control on the node creation you need to write up your own service for nodes using  hook_services_resources(). By default you can control only the access for creating a particular node using permissions. 

If you need to control node creation via node values, you need to go with your own services.