Use tenants

This guide shows you how to scope streams to tenants.

Every stream belongs to a tenant: its identity is the pair (tenant, stream ID). The default tenant is empty. Set the tenant once per request on the scoped DeedboxContext; every store in that scope loads and appends in it.

// Set the tenant and metadata once per request; every store in the request scope uses them.
app.Use(async (http, next) =>
{
    var deedbox = http.RequestServices.GetRequiredService<DeedboxContext>();
    deedbox.TenantId = http.Request.Headers["X-Tenant"].ToString();
    deedbox.Metadata = new EventMetadata
    {
        CorrelationId = http.TraceIdentifier,
        Actor = http.User.Identity?.Name is { } user ? $"user:{user}" : null,
    };
    await next(http);
});

• The same stream ID in two tenants is two streams.
• Async projections see all tenants, in one global order. ctx.TenantId names each event’s tenant.
• Each tenant has its own encryption key, so you can shred a whole tenant.
• A background job sets the tenant in its own scope before it resolves a store.

Tenant IDs are at most 100 characters with no leading or trailing white space.