BPA.CAP/docs/content/user-guide/en/persistent/in-memory-storage.md

In-Memory Storage

Persistent storage of memory messages is often used in development and test environments, and if you use memory-based storage you lose the reliability of local transaction messages.

Configuration

To use in-memory storage, you need to install the following extensions from NuGet:

PM> Install-Package DotNetCore.CAP.InMemoryStorage

Next, add configuration items to the ConfigureServices method of Startup.cs.

public void ConfigureServices(IServiceCollection services)
{
    // ...

    services.AddCap(x =>
    {
        x.UseInMemoryStorage();
        // x.UseXXX ...
    });
}

The successful message in memory, the CAP will be cleaned every 5 minutes.

Publish with transaction

In-Memory Storage Not supported Transaction mode to send messages.