Moongazing.MultiTenant

Moongazing.MultiTenant: Lightweight, flexible, production-ready multi-tenant framework for ASP.NET Core.

• Strongly-typed pipeline (TenantId, ITenantContext)
• Extensible resolution strategies (ITenantResolutionStrategy)
• Zero reflection at runtime
• Clean DI + middleware integration

Core + ASP.NET Core only. EF Core integration ships separately as Moongazing.MultiTenant.EFCore.

---

? Features

• ?? Header-based tenant resolution (default header X-Tenant-Id, configurable)
• ?? Scoped ITenantContext (with strongly-typed TenantId)
• ?? Tenant store abstraction (ITenantStore)
• ?? In-memory tenant store implementation
• ?? Pluggable resolution pipeline (strategies executed in registration order)
• ?? Middleware for per-request resolution
• ? No hidden static state / globals
• ?? Designed to extend (EF Core, gRPC, custom stores, custom strategies)

---

?? Installation

# From your ASP.NET Core project directory
dotnet add package Moongazing.MultiTenant

---

?? Quick Start

1?? Register multi-tenant services

builder.Services.AddMoongazingMultiTenant(options =>
{
    options.NotFoundMode = TenantNotFoundMode.Throw; // or UseDefault / Anonymous
    options.HeaderName = "X-Tenant-Id";              // customize if needed
});

2?? Provide tenant definitions

var tenants = new[]
{
    new TenantInfo
    {
        Id = new TenantId("tenant-a"),
        Name = "Tenant A",
        ConnectionString = "Host=...;Database=A;"
    },
    new TenantInfo
    {
        Id = new TenantId("tenant-b"),
        Name = "Tenant B",
        ConnectionString = "Host=...;Database=B;"
    }
};

builder.Services.AddInMemoryTenantStore(tenants);

3?? Add middleware

app.UseMoongazingMultiTenant();

4?? Consume ITenantContext

app.MapGet("/whoami", (ITenantContext tenant) => new { Tenant = tenant.Id });

Request example:

GET /whoami
X-Tenant-Id: tenant-a

---

?? How It Works

Resolution pipeline runs once per request:

[Strategy 1] ? [Strategy 2] ? [Strategy 3] ? First Match ? Resolved ITenantContext

Stops at first successful strategy.

Built-in strategy: HeaderTenantResolutionStrategy. Add your own (host, path, JWT claim, custom logic) by implementing the interface below.

---

?? Custom Resolution Strategy

public sealed class CustomStrategy : ITenantResolutionStrategy
{
    public Task<TenantResolutionResult> ResolveAsync(
        TenantResolutionContext context,
        CancellationToken cancellationToken = default)
    {
        var tenantId = context.Items.TryGetValue("Custom", out var value) ? value?.ToString() : null;
        if (!string.IsNullOrWhiteSpace(tenantId))
        {
            return Task.FromResult(
                TenantResolutionResult.FromSource(new TenantId(tenantId), "Custom")
            );
        }
        return Task.FromResult(TenantResolutionResult.NotFound());
    }
}

// Registration (order matters):
builder.Services.AddScoped<ITenantResolutionStrategy, CustomStrategy>();

---

?? TenantNotFoundMode

Mode	Behavior
Throw	Throws if tenant cannot be resolved (default)
UseDefault	Uses DefaultTenantId if set
Anonymous	Continues with unresolved context (IsResolved = false)

options.NotFoundMode = TenantNotFoundMode.UseDefault;
options.DefaultTenantId = new TenantId("tenant-a");

---

?? Key Abstractions

public interface ITenantContext
{
    bool IsResolved { get; }
    TenantId Id { get; }
    ITenantInfo Info { get; }
}

public interface ITenantStore
{
    Task<ITenantInfo?> FindByIdAsync(TenantId id, CancellationToken ct = default);
    Task<IReadOnlyList<ITenantInfo>> GetAllAsync(CancellationToken ct = default);
}

public sealed class MultiTenantOptions
{
    public TenantNotFoundMode NotFoundMode { get; set; } = TenantNotFoundMode.Throw;
    public TenantId? DefaultTenantId { get; set; }
    public string? HeaderName { get; set; } = "X-Tenant-Id";
}

---

?? EF Core Integration (Separate Package)

Planned features (in Moongazing.MultiTenant.EFCore):

• Tenant-scoped DbContext base class
• Per-tenant connection strings / schema
• Global query filters
• ITenantScoped marker interface

---

?? Testing

// Direct construction
var tenantInfo = new TenantInfo { Id = new TenantId("test"), Name = "Test", ConnectionString = "..." };
var tenantContext = new TenantContext(tenantInfo);

// Mocking store (example using NSubstitute)
var store = Substitute.For<ITenantStore>();
store.FindByIdAsync(new TenantId("t1")).Returns(tenantInfo);

---

?? Roadmap

v1.0.0

• ? Header-based strategy
• ? In-memory store
• ? Tenant context + middleware
• ? Namespace separation (Abstractions / Core / AspNetCore)

v1.1.0

• Host-based resolution
• Path-based resolution

v1.2.0

• JWT claim resolution
• Policy attributes ([TenantRequired], [TenantMatch])

v2.0

• Multi-tenant health checks
• Tenant feature flags
• Redis tenant store

---

?? Contributing

Contributions welcome.

Guidelines:

• Follow .editorconfig
• XML docs for public APIs
• Unit tests for new logic
• Meaningful commit messages

---

?? License

MIT License. See LICENSE file.

Packages

Package	Version	Downloads
Moongazing.MultiTenant	1.0.0	299