A contract (aqd) that involves the exchange of one counter-value for another. For example, exchanging a commodity for an amount of money (price/ thaman) is one form of an exchange-based contract. In general, exchange-based contracts can be classified into two main categories: sale-based contracts and lease-based contracts.

• Sale-based contracts: as the name implies, these contracts involve selling some valuable object for another. Examples include ba’i al-murabaha, ba’i al-salam, ba’i al-istisna’a, ba’i al-sarf, ba’i al-tawarruq, and so on.
• Lease-based contracts: this category includes lease contracts such as ijarat al-a’yan, ijarat al-ashkhas, and ijarat al-khadamat. The subject-matter of exchange in lease-based contracts is a specific usufruct, labor, or service.

The exchange in this type of contracts is two-way, with each party handing the other something of value in return.

It is also known as a commutative contract. or in Arabic as aqd al-mua’awadhah.