JSON-to-FIX Bridge Core

A production-grade financial gateway that bridges REST/JSON to the FIX 4.4 Protocol. Built for high-throughput institutional trading environments.

🚀 Key Features

• Java 21 Virtual Threads: High-concurrency "thread-per-request" model for non-blocking I/O.
• Netty Framework: Sub-millisecond latency on the HTTP ingress.
• Request Correlation: Async-to-Sync mapping using CompletableFuture and SessionRegistry.
• Resilience: Automatic FIX sequence recovery and session heartbeats.

🏗️ Architecture

The bridge acts as an intermediary. It receives JSON via HTTP POST, translates it into a FIX NewOrderSingle, and awaits an ExecutionReport to complete the original HTTP request.

🛠️ Getting Started

Prerequisites

• JDK 21+
• Maven 3.9+

1. Run the Mock Exchange (Simulator)

The simulator acts as the broker/exchange receiving your trades.

mvn test-compile exec:java -Dexec.mainClass="com.byteentropy.json_fix_bridge_core.FixExchangeSimulator" -Dexec.classpathScope=test

2. Start the Bridge

Bash
mvn compile exec:java -Dexec.mainClass="com.byteentropy.json_fix_bridge_core.JsonFixBridgeCoreApplication"

3. Send a Test Trade

Bash
curl -X POST [http://127.0.0.1:8080/](http://127.0.0.1:8080/) \
     -H "Content-Type: application/json" \
     -d '{
       "clOrdId": "TRD_1001",
       "symbol": "AAPL",
       "side": "BUY",
       "price": 150.25,
       "quantity": 100,
       "orderType": "LIMIT"
     }'

📊 Performance & Limits

• Backpressure: Default limit of 1,000 concurrent in-flight orders via Semaphores.

• Precision: Uses BigDecimal for all financial calculations to avoid floating-point errors.

LICENSE

MIT