SaaSify

A production-grade Multi-Tenant SaaS Platform built with .NET 8, demonstrating real-world architecture patterns.

Architecture Overview

SaaSify/
├── src/
│   ├── SaaSify.Api            # HTTP entry point
│   ├── SaaSify.Application    # CQRS handlers & business logic
│   ├── SaaSify.Domain         # Core entities, no dependencies
│   └── SaaSify.Infrastructure # EF Core, payments, AI
└── tests/
    └── SaaSify.Tests          # xUnit test suite

Layers

Layer	Responsibility	Key Dependencies
Domain	Entities, value objects, domain events, interfaces	None
Application	CQRS commands/queries via MediatR, validation, pipeline behaviours	Domain
Infrastructure	EF Core DbContext, multi-tenancy resolution, Stripe, Razorpay, Semantic Kernel	Domain, Application
Api	Controllers, middleware (tenant resolution, auth), DI wiring	Application, Infrastructure
Tests	Unit & integration tests	Application, Domain

Dependency Flow

Api → Application → Domain
Api → Infrastructure → Domain
         ↑
  Infrastructure also → Application (implements interfaces)

Domain is the innermost ring — it has zero external dependencies.

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Key Features

Multi-Tenant Data Isolation

Each tenant's data is scoped at the database level via a TenantId discriminator. The ITenantContext interface (resolved per-request from the JWT or subdomain) is injected into the EF Core DbContext to automatically filter all queries.

CQRS with MediatR

Commands mutate state; queries return read models. Pipeline behaviours in Application/Common/Behaviours handle cross-cutting concerns (logging, validation, performance). Handlers live under feature folders (Tenants/, Subscriptions/).

Payment Integration

• Stripe — primary payment gateway for subscription billing and webhooks.
• Razorpay — secondary gateway for INR-denominated markets. Both are abstracted behind an IPaymentGateway interface so the application layer stays provider-agnostic.

AI Assistant

Microsoft Semantic Kernel connects to Azure OpenAI to power a tenant-scoped AI assistant. Plugins in Infrastructure/AI implement the SK plugin interface and can be swapped for other providers.

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Getting Started

# Restore dependencies
dotnet restore

# Build
dotnet build

# Run API
dotnet run --project src/SaaSify.Api

# Run tests
dotnet test

Tech Stack

• .NET 8 / ASP.NET Core
• MediatR 12
• Entity Framework Core 8
• Stripe.net / Razorpay SDK
• Microsoft Semantic Kernel
• Azure OpenAI
• xUnit + FluentAssertions