Multi-tiered message parsing

Methods and apparatus, including computer program products, for multi-tiered parsing of messages. A message that includes data characterizing values is received, the message is parsed to obtain the values as a first data type, and an instance of a value being of a second data type is generated in response to a request for the value. The requested value is one of the values characterized by the data in the message. The first and second data type are different, and, the second data type is associated with the requested value (e.g., the message may indicate that the first value is of the second data type). The parsing may be considered multi-tiered as parsing to obtain values as a first data type may be considered a first tier and generating an instance of a value as a second data type may be considered a second tier of an overall parsing technique.