From at least the beginning of the 19th century, Omani merchants and planters and their Indian financiers had been settling East Africa in growing numbers, as they sought to participate in the increasingly lucrative ivory and slave trades and a burgeoning plantation economy. Faced with a state that was unable to extend its authority beyond the walls of its capital, an informal grouping of commercial and juridical actors fashioned a property rights regime that operated largely outside of state structures. By fashioning enduring bonds of debt and obligation with one another, they were able to mitigate the risks associated with trade, and in the process tied together the distant shores of this vast oceanic world of commerce. A central component in the making of this world was law, which furnished the concepts and instruments necessary to organize migration, commerce and settlement between Oman and East Africa, and which provided a philosophy to the nature and shape of the obligations that ran through it, and the institutions that governed it. Drawing on legal instruments from Oman and East Africa and combining them with manuals of Islamic jurisprudence (fiqh) and legal opinions, (fatawa), this paper explores how ideas of law, encapsulated in the written obligation, the waraqa (literally, “paper”), traveled through across the Western Indian Ocean during the 19th century. As a commercial and legal instrument, the waraqa gave articulation to the bonds of obligation that tied commercial actors in as far-flung areas as Tanganyika and the Omani interior together. At the same time, it also gave these bonds a legal shape, drawing on a long genealogy of Islamic commercial jurisprudence to ground these networks in an Islamicate legal episteme. And as commercial actors moved from Oman to the East African coast, and into the interior, they brought these concepts along with them in the form of the waraqas they carried with them and the groups of actors that gave shape to them. The waraqa thus gives us a window into a history of non-state commercial and juridical expansion across an ocean that historians are only beginning to appreciate.