A programming model provides a method for type inference in programming operations. Information defining one or more attributes of an operation is received, the information specifying a field including a field name and a field type identifier for each of the attributes. Constraints for the operation are determined at least based on the attributes, wherein the constraints restrict at least one of a type of input for the operation or a type of output for the operation. Information defining an input for the operation is received, and it is determined, based on the constraints and the received information defining the input, the type of output for the operation. The type of output is associated with an output for the operation.