SoftTraderBackend/README.md

SoftTrader Backend

A .NET 10 Web API backend for a lite Bloomberg-style terminal. Provides live and historical equity data via Interactive Brokers, AI-driven news sentiment analysis using FinBERT, configurable price alerts, and supporting services like weather and chart annotations.

Prerequisites

• .NET 10 SDK
• PostgreSQL
• Interactive Brokers Gateway running on 127.0.0.1:4002
• FinBERT ONNX model files in AIModels/finbert/ (model.onnx, vocab.txt, tokenizer configs)

Getting Started

1. Configure the database — update the connection string in appsettings.json:

   "ConnectionStrings": {
     "MarketDataDb": "Host=127.0.0.1;Port=5432;Database=softtraderbackend_pricedata;Username=postgres;Password=<your-password>"
   }
   

2. Start IB Gateway — the application connects on startup and will exit if the connection fails.

3. Run the application:

   dotnet run
   

   The API starts on http://localhost:5000 by default.

4. Swagger UI is available at /swagger for interactive API exploration (no API key required).

Authentication

All API endpoints (except Swagger) require an API key via the X-Api-Key header. Keys are validated against PostgreSQL.

API Endpoints

Market Data — /api/market

Method	Route	Description
GET	/live/{symbol}	Live quote from IB Gateway
GET	/historical	Historical OHLCV bars (configurable duration, bar size, data type)
GET	/historical-line	Historical line data
GET	/symbol-check/{symbol}	Validate a ticker symbol
GET	/last-trading-day	Last trading day for a symbol

News Sentiment — /api/news-sentiment

Method	Route	Description
GET	/	Analyze sentiment for a keyword (fetches Google News RSS, scores with FinBERT)
GET	/feed	Personalized news feed based on user interests
GET	/refresh	Refresh sentiment data for all of a user's tracked symbols/topics

Alerts — /api/alerts

Method	Route	Description
POST	/create	Create a price alert
GET	/list	List all alerts for a user
GET	/triggered	List triggered alerts for a user
DELETE	/delete	Delete an alert

Alert types: price_threshold, percent_change, price_spike, trailing_price

Alerts are evaluated by a background service every minute during market hours (Mon–Fri, 6 AM – 2 PM Pacific).

User Interests — /api/user-interest

Method	Route	Description
GET	/fetch	Get a user's tracked symbols or topics
POST	/add	Add a symbol or topic
DELETE	/remove	Remove a symbol or topic

Annotations — /api/annotations

Method	Route	Description
GET	/fetch	Get saved chart annotations for a user/symbol
POST	/save	Save chart annotations
DELETE	/delete	Delete chart annotations

Weather — /api/weather

Method	Route	Description
PUT	/set-location	Set a user's city (geocoded)
GET	/current	Get current weather for a user's saved location

Architecture

Backend/
├── Controller/          # REST API controllers
├── ServiceHandler/      # Business logic (market data, news, alerts, weather)
├── DatabaseHandler/     # PostgreSQL data access via Npgsql (no ORM)
├── Interface/           # Store and service abstractions
├── Middleware/           # API key auth, global exception filter
├── MarketDataRequest/   # IB Gateway integration and request/response models
└── AIModels/finbert/    # FinBERT ONNX model and tokenizer files

Background Services

• AlertEvaluationService — polls active alerts every minute during market hours and evaluates them against live prices
• NewsSentimentRefreshService — periodically refreshes news sentiment data for tracked interests

Dependencies

Package	Purpose
Microsoft.ML.OnnxRuntime	FinBERT model inference
Npgsql	PostgreSQL driver
Swashbuckle.AspNetCore	Swagger / OpenAPI
twsapi (project ref)	Interactive Brokers TWS API client