Building Real-Time Event-Driven Applications with FluxRail: A Step-by-Step Guide

Introduction

In the fast-paced world of blockchain and fintech, real-time event-driven architecture is no longer optional—it's a necessity. Whether you're building a payment gateway, a remittance platform, or a crypto exchange, your systems need to react instantly to on-chain events and settlement updates. FluxRail's unified API makes this possible by providing real-time blockchain monitoring, gas-free transfers, liquidity, and payouts—all through a single integration. In this guide, we'll walk through building a complete event-driven application using FluxRail, from setting up webhooks to handling payouts, all with simple HTTP requests.

Prerequisites

Before diving in, ensure you have:

• A FluxRail account with an API key (test mode: flux_test_...)
• Basic knowledge of REST APIs and webhooks
• A tool like curl or Postman for testing

Step 1: Set Up Your Webhook Endpoint

First, you need an endpoint to receive events. For this example, we'll use a simple webhook receiver (e.g., a Node.js server) that logs incoming events. But for demonstration, we'll just show how to configure the webhook in FluxRail.

Create a webhook subscription:

curl -X POST https://api.fluxrail.io/api/v1/webhooks \
  -H "X-API-Key: flux_test_xxx" \
  -H "Content-Type: application/json" \
  -d '{
    "url": "https://your-server.com/webhook",
    "events": ["subscription.event", "transfer.completed", "payout.settled"]
  }'

FluxRail will respond with a webhook ID and a signing secret. Store the secret securely; you'll use it to verify signatures.

Step 2: Monitor Blockchain Events with Core

Real-time monitoring starts with creating subscriptions. For example, to watch a specific Ethereum address for incoming USDC:

curl -X POST https://api.fluxrail.io/api/v1/subscriptions \
  -H "X-API-Key: flux_test_xxx" \
  -H "Content-Type: application/json" \
  -d '{
    "chain": "ethereum",
    "address": "0xYourAddressHere",
    "event_types": ["token_transfer"],
    "webhook_url": "https://your-server.com/webhook"
  }'

Now, whenever a token transfer occurs to that address, FluxRail will send a signed webhook to your endpoint. The payload includes details like amount, token, and transaction hash.

Step 3: Verify Webhook Signatures

To ensure the webhook is genuinely from FluxRail, verify the X-FluxRail-Signature header using HMAC SHA-256 with your signing secret. Here's a Python example using requests:

import hashlib, hmac, json

def verify_signature(payload, signature, secret):
    computed = hmac.new(secret.encode(), payload.encode(), hashlib.sha256).hexdigest()
    return hmac.compare_digest(computed, signature)

# In your webhook handler:
# payload = request.body.decode()
# signature = request.headers['X-FluxRail-Signature']
# if not verify_signature(payload, signature, 'your_secret'):
#     raise Exception('Invalid signature')

Step 4: React to Events

Once you receive an event, you can trigger business logic. For example, when a customer funds their account (via a subscription event), you might want to credit their balance. Or, when a payout settles, you can update your database and notify the user.

Step 5: Execute Gas-Free Transfers with Pay

Suppose you need to move funds to another address. FluxRail's Pay product sponsors gas fees, so the user doesn't need ETH. Use the transfer endpoint:

curl -X POST https://api.fluxrail.io/api/v1/transfer \
  -H "X-API-Key: flux_test_xxx" \
  -H "Content-Type: application/json" \
  -d '{
    "token": "USDC",
    "network": "ERC20",
    "amount": "50.00",
    "recipient": "0xRecipientAddress",
    "client_reference_id": "transfer_123"
  }'

The response includes a transfer ID. You'll receive a transfer.completed webhook when it's done.

Step 6: Convert Assets with Liquidity

If you need to swap USDC for USDT, use the liquidity endpoints. First, get a quote:

curl -X POST https://api.fluxrail.io/api/v1/liquidity/quote \
  -H "X-API-Key: flux_test_xxx" \
  -H "Content-Type: application/json" \
  -d '{
    "sell_token": "USDC",
    "buy_token": "USDT",
    "sell_amount": "100.00",
    "network": "ERC20"
  }'

Then execute the swap:

curl -X POST https://api.fluxrail.io/api/v1/liquidity/execute/{quote_id} \
  -H "X-API-Key: flux_test_xxx"

Step 7: Make Payouts

Finally, to send funds to a bank account, create a payout customer and then send a payout. First, create a customer:

curl -X POST https://api.fluxrail.io/api/v1/payouts/customers \
  -H "X-API-Key: flux_test_xxx" \
  -H "Content-Type: application/json" \
  -d '{
    "type": "individual",
    "external_id": "cust_123",
    "name": "Jane Doe",
    "email": "jane@example.com"
  }'

Then initiate a payout to a US bank account via ACH:

curl -X POST https://api.fluxrail.io/api/v1/payouts/customers/cust_123/send \
  -H "X-API-Key: flux_test_xxx" \
  -H "Content-Type: application/json" \
  -d '{
    "token": "USDC",
    "network": "ERC20",
    "amount": "250.00",
    "dest_currency": "USD",
    "method": "ach",
    "destination": {
      "account_owner_name": "Jane Doe",
      "account_number": "000123456789",
      "routing_number": "110000000",
      "account_type": "checking"
    }
  }'

FluxRail will handle compliance screening and settlement. You'll receive webhooks for status changes like payout.pending_approval, payout.settled, etc.

Step 8: Handle Webhooks in Production

Make your webhook handler idempotent: process each event only once. Use the event ID to deduplicate. Also, retry failed webhook deliveries by calling the retry endpoint:

curl -X POST https://api.fluxrail.io/api/v1/events/{event_id}/retry \
  -H "X-API-Key: flux_test_xxx"

Conclusion

With FluxRail, you've built a real-time event-driven application that monitors blockchain activity, executes transfers, swaps assets, and settles payouts—all with a single API and no SDK. The key is to leverage webhooks for reactive logic and use the REST endpoints for actions. Start with test mode to simulate the entire lifecycle, then switch to live keys when ready. For more details, check the documentation.