This chapter describes an object-based workflow paradigm to support long and short duration transactions in a mobile e-commerce (or m-commerce) environment. In the mobile computing environment, the traditional transaction model needs to be replaced by a more realistic model (called a “workflow model”) between several clients and servers that interact, compete, and cooperate, realising an intergalactic client-server program (ICSP). The various types of task patterns that arise in m-commerce (e-checking, shipping goods, purchasing, and market forecasting) require a subjunctive, or “what-if,” programming approach, consisting of intention and actions for trial-error design, before an actual commitment is made. Eiffel, iContract tool of Java, and UML are powerful languages to implement the intergalactic client-server program (ICSP). They provide for a software contract that captures mutual obligations through program constructs to take care of the unpredictable nature of connectivity of the mobile devices and the networks, as well as the trial and error program design required in m-commerce.