The SAP Fiori - Mockserver is the core middleware used by the ui5 middleware of the same name.
It provides a middleware that can be used in standard express or http.Router based application.
npm
npm install --save-dev @sap-ux/fe-mockserver-core
yarn
yarn add @sap-ux/fe-mockserver-core --dev
pnpm
pnpm add @sap-ux/fe-mockserver-core --dev
Most likely you will consume this through the @sap-ux/ui5-middleware-fe-mockserver package, otherwise do check the tests as it is not meant to be consumed directly :)
Mockserver