Portfolio Analytics Backend

ASP.NET Core backend for portfolio analytics, stock fundamentals, user portfolios, transactions, and local financial data analysis.

The project is designed as a portfolio and training backend. It supports local SQLite persistence, JWT authentication, Swagger documentation, demo seed data, and optional integration with external financial data providers.

Current Status

The backend is in active development and currently supports:

• user registration and login with JWT authentication
• refresh tokens
• user cash balance
• portfolio holdings
• buy/sell transactions
• local ticker database
• quote and time-series endpoints
• fundamental data storage
• analytics endpoints for financial ratios
• SQLite persistence with EF Core migrations
• Swagger/OpenAPI documentation
• demo seed data for selected companies

Demo And API Key Behavior

The project is intended to run locally without external API keys for demo and database-backed workflows.

External provider keys are only required for live data ingestion:

• Financial Modeling Prep: fundamentals and company profile data
• Alpha Vantage: quote and price data

Without API keys, database-backed workflows can use local seed data and stored records. Live ingestion endpoints require provider keys.

Demo data is stored in:

Portfolio.Api/SeedData/companies/
Portfolio.Api/Data/companies-fallback.json

Tech Stack

• C#
• .NET 8
• ASP.NET Core Web API
• EF Core
• SQLite
• JWT authentication
• Swagger/OpenAPI
• xUnit
• Financial Modeling Prep integration
• Alpha Vantage integration

Run The API

From the repository root:

cd .\Portfolio.Api
dotnet run

The API listens on:

http://localhost:5046

Swagger UI is available at:

http://localhost:5046/swagger

Configuration

Default local configuration uses SQLite:

{
  "ConnectionStrings": {
    "Default": "Data Source=portfolio.db"
  },
  "AlphaVantage": {
    "BaseUrl": "https://www.alphavantage.co",
    "ApiKey": ""
  },
  "Fmp": {
    "ApiKey": ""
  },
  "Jwt": {
    "Secret": "CHANGE_ME_USE_USER_SECRETS"
  },
  "DemoMode": true
}

For local authentication and optional live external data, configure user secrets:

cd .\Portfolio.Api

dotnet user-secrets set "Jwt:Secret" "<your-local-jwt-secret>"
dotnet user-secrets set "Fmp:ApiKey" "<your-fmp-api-key>"
dotnet user-secrets set "AlphaVantage:ApiKey" "<your-alpha-vantage-api-key>"

Jwt:Secret is required for authentication. Fmp:ApiKey and AlphaVantage:ApiKey are only required for live provider calls.

Do not commit real API keys, secrets, or local database files.

Database

The local SQLite database file is created as:

Portfolio.Api/portfolio.db

Database files are ignored by Git.

To reset local data during development, stop the API and remove or rename the database file:

cd .\Portfolio.Api
Rename-Item .\portfolio.db portfolio.old.db

Then start the API again.

Main API Areas

System

• GET /health
• Swagger UI: http://localhost:5046/swagger

Users

• POST /api/User/register
• POST /api/User/login
• POST /api/User/refresh
• POST /api/User/logout
• GET /api/User/me
• GET /api/User/balance
• POST /api/User/deposit
• POST /api/User/withdraw

Portfolio

• GET /api/UserCompany
• POST /api/UserCompany
• PUT /api/UserCompany/{id}
• DELETE /api/UserCompany/{id}

Transactions

• POST /api/UserCompanyTransactions
• GET /api/UserCompanyTransactions/mine
• GET /api/UserCompanyTransactions/by-symbol/{symbol}

Companies

• GET /api/companies
• GET /api/companies/search
• POST /api/companies/add
• POST /api/companies/add-popular

Quotes And Analytics

• GET /api/quotes/latest
• GET /api/quotes/timeseries
• GET /api/quotes/ohlc
• GET /api/analytics/roe
• GET /api/analytics/pe
• GET /api/analytics/pb
• GET /api/analytics/fcf-yield

Tests

Run tests from the repository root:

dotnet test

Documentation

• Detailed backend guide
• Analytics endpoints
• OpenAPI specification
• Postman collection
• Commit conventions

Related Projects

Frontend repository:

portfolio-analytics-frontend

Notes

This project is a portfolio and training project focused on ASP.NET Core, EF Core, authentication, financial data modeling, local-first workflows, and API integration.