Multi-tenancy

Multi-tenancy (preview) is a common architecture, and the template includes support.

Consider two groups:

• 1000+ standard tenants: small datasets, minimal isolation, cost-sensitive.
• 10+ large tenants: very large datasets, require isolation, prioritize stability over cost.

Enable Multi-tenancy

In AppHost/appsettings.Development.json, set:

"Components": {
    "Cache": "Hybrid",
    "Database": "PostgreSQL",
    "IsMultiTenant": true
  }

IsMultiTenant toggles multi-tenant features.

Implementation

The framework supports multi-tenancy out of the box. Keep writing code as usual and focus on TenantContext and TenantDbFactory.

TenantDbFactory injects ITenantContext to obtain tenant info and per-tenant connection strings.

Tenant.cs defines core tenant data; extend as needed.

Clients include TenantId in tokens; servers derive tenant identity from TenantId on subsequent requests.

Handle TenantId at Login

Before login, the backend cannot know the tenant. On login, infer the tenant (domain, email suffix, or explicit identifier) and include TenantId in the returned token.

public async Task<AccessTokenDto> LoginAsync(SystemLoginDto dto)
{
    var domain = dto.Email.Split("@").Last();
    var tenant = await _dbContext.Tenants.Where(t => t.Domain == domain).FirstOrDefaultAsync()
        ?? throw new BusinessException(Localizer.TenantNotExist);
    tenantContext.TenantId = tenant.Id;
    tenantContext.TenantType = tenant.Type.ToString();
    var user = await _dbSet
        .Where(u => u.Email == dto.Email)
        .Include(u => u.SystemRoles)
        .FirstOrDefaultAsync() ?? throw new BusinessException(Localizer.UserNotExists);
    // Return Token
}

Since there’s no token pre-login, set TenantId on the injected ITenantContext so downstream logic recognizes the correct tenant.

TenantId Indexes

You don’t need to add TenantId indexes manually. The framework applies them automatically (including filtered indexes to ignore soft-deleted rows) so single-tenant and multi-tenant modes remain correct.

During EF migrations, MigrationsModelDifferProxy in MigrationService handles TenantId index generation.

Without Multi-tenancy

The template is multi-tenant–compatible by default. Even with multi-tenancy disabled, it creates a Tenant table and TenantId on entities to allow a smooth future enablement.

If you will never use multi-tenancy and want to remove it:

1. Remove Tenants from ContextBase.cs.
2. Make EntityBase.cs inherit IEntityBase instead of ITenantEntityBase and remove TenantId.