Package sequence provides monotonically increasing counters similar to the autoincrement sequence objects that are available in databases like PostgreSQL. While this type of object is simple to implement, stateful representations are used in a wide variety of projects and this package is about having a standard API and interface to reuse these objects without fear. In particular, this project does not implement simple counters or iterables, but is designed to maximize the sequence space for constant growth and to raise errors when sequences become too large. The primary interface is the Sequence object, which essentially wraps a 64-bit unsigned integer, providing the single largest positive integer range. The Sequence object implements the Incrementer interface, which specifies how to interact with the Sequence object. Simple usage is as follows: By default, this will provide an integer sequence in the positive range 1 - 18,446,744,073,709,551,614. Note that sequences start at one as they are typically used to compute autoincrement positive ids. The Sequence.Next() method will return an error if it reaches the maximum bound, which by default is the maximal uint64 value, such that incrementing will not start to repeat values. If the increment is negative, then the sequence will return an error if it reaches a minimum bound, which by default is 0 since the Sequence will always return positive values. The Sequence object provides several helper methods to interact with it during long running processes, including Current(), IsStarted(), and String() methods which return information about the state of the Sequence. Interacting with sequences across processes is provided through the Sequence.Dump and Sequence.Load methods, which serialize the Sequence to a []byte JSON representation. Note that this does not use the standard json.Marshal and json.Unmarshal interface in order to keep members of the sequence inaccessible outside the library, ensuring that a sequence cannot be modified except to be restarted.