The Cache interface provides a persistent storage mechanism for Request / Response object pairs that are cached in long lived memory. How long a Cache object lives is browser dependent, but a single origin's scripts can typically rely on the presence of a previously populated Cache object. Note...
When setting BANano.TranspilerOptions.UseServiceWorker = true (or BANano.TranspilerOptions.UseServiceWorkerWithUpdateMessage in an upcoming version) this is already done by BANano automatically using this Cache API. The API itself will not be exposed, as it is all part of the plan 'to keep everything as simple as possible'.