Juniper Extension Toolkit (JET) packages support JET applications on the device and provide the framework for application development.
There is a difference in packaging of client APIs between development for on-device applications and development for off-box applications. By default, a set of JET package modules is installed on-device. These modules provide a set of wrapper Python APIs for developing JET applications. For applications to run off-box, the IDL files should be complied.
Junos PyEZ—A microframework for Python that comes installed on the device. The PyEZ microframework enables you to remotely manage and automate devices running Junos OS. Junos PyEZ is designed to provide the capabilities that a user would have on the Junos OS command-line interface (CLI) in an environment built for automation tasks. For more information, see Junos PyEZ.
jsd package—The JET service process (jsd) runs on Junos OS. It is bundled with the Junos install packages. It is not necessary to install or upgrade jsd separately from the base Junos OS. By default, jsd listens for API execution requests on TCP prot 32767.