🛡️ Sentri

Infrastructure spend tracking for contractors and developers.
Know when you're over budget.

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What is Sentri?

Sentri is a self-hosted REST API designed to help contractors and developers track infrastructure costs across multiple cloud providers (AWS, DigitalOcean, Vercel, etc.). Define monthly budgets per provider, log expenses as they happen, and get email alerts automatically when spend approaches a configurable warning threshold . so you never get hit by a surprise bill.

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✨ Features

Feature	Description
Provider Management	Create and manage infrastructure providers with monthly budgets and warning thresholds
Expense Tracking	Register individual expenses against any provider
Monthly Budget Cycles	Automatic monthly snapshots isolate spending periods cleanly
Threshold Alerts	Email notifications via Brevo when spending crosses your warning threshold
JWT Authentication	Secure, per-user data isolation out of the box
Vertical Slice Architecture	Features are fully self-contained . easy to navigate, easy to extend

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🏗️ Architecture

Sentri is built on Vertical Slice Architecture . each feature owns its own request, handler, response, and endpoint. There are no shared services leaking across feature boundaries.

Sentri.Api/
├── Domain/               # Core entities & domain events
│   ├── Provider.cs
│   ├── Expense.cs
│   ├── ProviderMonthlySnapshot.cs
│   └── User.cs
├── Features/             # One folder per use case
│   ├── Auth/             # Register & login
│   ├── Providers/        # CRUD + expense registration
│   ├── Expenses/         # Expense queries
│   └── Notifications/    # Brevo email integration
└── Infrastructure/       # EF Core DbContext & migrations

Key technology choices:

• ASP.NET Core 10 . Minimal APIs, no controllers
• Entity Framework Core 10 . PostgreSQL via Npgsql
• MediatR . Internal event dispatch (domain events)
• JWT Bearer . Stateless authentication
• xUnit + FluentAssertions + NSubstitute . Test stack
• coverlet . Code coverage collection

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🚀 Getting Started

Prerequisites

• .NET 10 SDK
• PostgreSQL instance (local or Docker)
• A Brevo API key (for email alerts)

1. Clone the repo

git clone https://github.com/fernandesdiego/Sentri.git
cd Sentri

2. Configure secrets

cd src/Sentri.Api

dotnet user-secrets set "ConnectionStrings:DefaultConnection" "Host=localhost;Database=sentri;Username=postgres;Password=yourpassword"
dotnet user-secrets set "JwtSettings:Key" "your-super-secret-key-at-least-32-chars"
dotnet user-secrets set "JwtSettings:Issuer" "sentri"
dotnet user-secrets set "JwtSettings:Audience" "sentri-users"
dotnet user-secrets set "Brevo:ApiKey" "your-brevo-api-key"

3. Apply migrations

dotnet ef database update

4. Run the API

dotnet run

Swagger UI is available at https://localhost:{port}/swagger in development mode.

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🔁 API Overview

Method	Endpoint	Description	Auth
POST	/auth/register	Register a new user	❌
POST	/auth/login	Get a JWT token	❌
GET	/providers	List all your providers	✅
GET	/providers/{id}	Get a single provider	✅
POST	/providers	Create a provider	✅
POST	/providers/{id}/expenses	Register an expense	✅
GET	/providers/{id}/expenses	List provider expenses	✅

All authenticated endpoints scope data strictly to the authenticated user.

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🧪 Running Tests

dotnet test

With coverage:

dotnet test --collect:"XPlat Code Coverage"

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🔔 Budget Alerts

When an expense pushes a provider's monthly spend past its WarningThreshold (a value between 0–1 representing the fraction of MonthlyBudget), Sentri automatically fires a domain event that triggers an email notification via Brevo. No polling, no cron jobs.

Example: A provider with a $100 budget and a 0.8 threshold will trigger an alert the moment cumulative spend in the current month exceeds $80.

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🤝 Contributing

This is a personal project and is not currently accepting contributions. Feel free to fork and adapt it for your own use.