The MODFLOW API allows other programs to control MODFLOW and interactively change variables without having to modify the source code. The MODFLOW API is based on the Basic Model Interface (BMI), which is a set of conventions that define how to initialize a simulation, update the model state by advancing in time, and finalize the run. For many existing MODFLOW coupling applications, the information provided to MODFLOW must be updated multiple times in a time step. As this capability to modify variables within a time step is not defined by the BMI, an extension to BMI was developed. This eXtended Model Interface is part of the MODFLOW API and allows such a tight coupling to other models. Examples are included for a variety of use cases, including new flexibility for users to develop custom packages without modifying the MODFLOW source code and coupling MODFLOW with other models and optimization libraries.

MODFLOW API 允许其他程序控制 MODFLOW 并以交互方式更改变量，而无需修改源代码。MODFLOW API 基于基本模型接口 (BMI)，这是一组约定，用于定义如何初始化模拟、通过及时更新模型状态以及完成运行。对于许多现有的 MODFLOW 耦合应用程序，提供给 MODFLOW 的信息必须在一个时间步长内多次更新。由于这种在时间步长内修改变量的能力不是由 BMI 定义的，因此开发了对 BMI 的扩展。这个扩展模型接口是 MODFLOW API 的一部分，允许与其他模型紧密耦合。包括各种用例的示例，