# LDK Architecture

LDK Architecture

LDK's core components are shown in the center box labeled lightning. Boxes with dotted borders are LDK's batteries — these must be configured with either off-the-shelf or custom implementations that you provide.

EventHandler in the diagram is not so much a necessary LDK battery, but instead refers to the fact that LDK generates events that the user should handle (e.g. the PaymentReceived event).