Muonroi.Tenancy 1.0.0-alpha.16

Muonroi.Tenancy

ASP.NET Core runtime layer for multi-tenancy: request-scoped tenant resolution middleware, per-tenant Redis cache, and OpenTelemetry metrics for auth failures.

Muonroi.Tenancy is the ASP.NET Core runtime package of the Muonroi multi-tenancy stack. It provides TenantResolutionMiddleware — which extracts the tenant ID from the HTTP request (header, path segment, or subdomain), validates it against the caller's JWT claim, and propagates it through TenantContext.CurrentTenantId for the duration of the request. The package also ships RedisTenantCache, a Redis wrapper that namespaces all keys under tenant:{tenantId}: for clean per-tenant isolation, and TenantResolutionTelemetry, which emits OTel-native counters for auth failures.

This package depends on Muonroi.Tenancy.Abstractions (contracts) and Muonroi.Tenancy.Core (context propagation and DI helpers).

Installation

dotnet add package Muonroi.Tenancy --prerelease

Quick Start

Register core tenancy services from Muonroi.Tenancy.Core, then add the middleware:

// Program.cs
using Muonroi.Tenancy.Core.Legacy;   // AddTenantContext
using Muonroi.Tenancy;               // TenantResolutionMiddleware

WebApplicationBuilder builder = WebApplication.CreateBuilder(args);

// Register tenant context and connection-string factory
builder.Services.AddTenantContext(options =>
{
    builder.Configuration.GetSection("MultiTenant").Bind(options);
});

WebApplication app = builder.Build();

// Place after UseAuthentication / UseAuthorization so the JWT claim is available
app.UseAuthentication();
app.UseAuthorization();
app.UseMiddleware<TenantResolutionMiddleware>();

app.MapControllers();
app.Run();

After the middleware runs, read the resolved tenant ID anywhere in the request pipeline:

string? tenantId = TenantContext.CurrentTenantId;

Per-tenant Redis cache

// Inject IConnectionMultiplexer (registered via StackExchange.Redis)
IConnectionMultiplexer redis = ConnectionMultiplexer.Connect("localhost:6379");
var cache = new RedisTenantCache(redis, tenantId: "acme");

await cache.SetAsync("settings:theme", "dark", expiry: TimeSpan.FromHours(1));
RedisValue theme = await cache.GetAsync("settings:theme");

Features

• Multi-source tenant resolution: checks the custom request header (X-Tenant-Id via CustomHeader.TenantId), then the first URL path segment, then the subdomain — in that order of precedence.
• Format validation: tenant IDs must match ^[a-zA-Z0-9][a-zA-Z0-9._-]{0,63}$; malformed input returns 400 Bad Request.
• JWT claim cross-check: if a resolved tenant ID conflicts with the tenant_id JWT claim the middleware returns 401 Unauthorized; a missing claim also yields 401.
• AsyncLocal propagation: TenantContext.CurrentTenantId is set for the request scope and cleared in the finally block — safe for async code.
• OpenTelemetry tracing: tenant ID is written to Activity.Current as both a tag (tenant.id) and baggage for distributed trace correlation.
• Per-tenant Redis isolation: RedisTenantCache prefixes every key with tenant:{tenantId}: and uses SCAN (not KEYS) for bulk enumeration.
• OTel metrics: TenantResolutionTelemetry exposes a Counter<long> instrument (muonroi.tenancy.auth_failures) with failure_reason, header_tenant_id, and claim_tenant_id dimensions.

Configuration

Tenant context options live in Muonroi.Tenancy.Core. Bind them from appsettings.json:

{
  "MultiTenant": {
    "DefaultTenantId": "default",
    "ConnectionStrings": {
      "acme": "Server=acme-db;Database=acme;...",
      "beta": "Server=beta-db;Database=beta;..."
    }
  }
}

Register in DI using the extension from Muonroi.Tenancy.Core:

builder.Services.AddTenantContext(options =>
    builder.Configuration.GetSection("MultiTenant").Bind(options));

API Reference

Samples

• MultiTenantSaaS — SaaS pricing API demonstrating per-tenant rule evaluation with license-tier enforcement

Compatibility

• Target framework: net8.0
• Requires: Microsoft.AspNetCore.App framework reference, StackExchange.Redis
• License: Apache-2.0 (OSS)

Related Packages

• Muonroi.Tenancy.Abstractions — contracts: ITenantContext, ITenantIdResolver, MultiTenantOptions, quota interfaces
• Muonroi.Tenancy.Core — core implementations: TenantContext, DefaultTenantIdResolver, TenantSchemaSelector, AddTenantContext DI extension
• Muonroi.Tenancy.SiteProfile — site-profile layer for multi-site deployments with per-site EF Core / Dapper infrastructure

License

Apache-2.0. See LICENSE-APACHE for details.