Monitor & Manage Multi-Chain Wallets with FluxRail

Introduction

Managing wallets across multiple blockchains is a constant challenge for Web3 developers, exchanges, and fintechs. Each chain has its own RPC endpoint, event format, and transaction lifecycle. FluxRail unifies this complexity into a single API. In this post, you'll learn how to use FluxRail's Core (blockchain monitoring) and Wallet (stateless helpers) products to monitor addresses, detect events, and manage wallets programmatically—all without ever touching an RPC provider or running a node.

Prerequisites

You need a FluxRail account and an API key. Sign up at fluxrail.io and grab your test key (flux_test_…) from the dashboard. All examples use curl against https://api.fluxrail.io with the X-API-Key header. Replace the placeholder key with your own.

Step 1: List Supported Chains

First, see which chains FluxRail supports. The GET /api/v1/chains endpoint returns an array of chain objects with slugs you'll use later.

curl -s https://api.fluxrail.io/api/v1/chains \
  -H "X-API-Key: flux_test_abc123" | jq '.data[].slug'

Sample output: "ethereum", "polygon", "arbitrum", "solana", "bitcoin", etc. You can filter by ?type=evm or ?testnet=true.

Step 2: Generate a Wallet Mnemonic

FluxRail's Wallet product provides stateless helpers to generate mnemonics, derive addresses, and validate addresses. No private keys are stored—you control them. Generate a 12-word mnemonic:

curl -X POST https://api.fluxrail.io/api/v1/wallet/mnemonic \
  -H "X-API-Key: flux_test_abc123" \
  -H "Content-Type: application/json" \
  -d '{"strength":128}'

Response includes mnemonic (words) and entropy. Save the mnemonic securely—it's your seed.

Step 3: Derive Addresses for Multiple Chains

Use the mnemonic to derive addresses for Ethereum, Polygon, and Solana:

curl -X POST https://api.fluxrail.io/api/v1/wallet/derive \
  -H "X-API-Key: flux_test_abc123" \
  -H "Content-Type: application/json" \
  -d '{
    "mnemonic": "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about",
    "chains": ["ethereum","polygon","solana"],
    "account": 0,
    "change": 0,
    "index": 0
  }'

FluxRail returns a map of chain → address. For EVM chains, it derives the same address (since they share the same derivation path). Solana gets its own.

Step 4: Subscribe to Address Events

Now monitor those addresses. Create a subscription for each address. FluxRail will watch for incoming/outgoing transactions and send signed webhooks to your endpoint. First, configure a webhook endpoint:

curl -X POST https://api.fluxrail.io/api/v1/webhooks \
  -H "X-API-Key: flux_test_abc123" \
  -H "Content-Type: application/json" \
  -d '{
    "url": "https://your-server.com/webhook",
    "description": "Multi-chain wallet monitor",
    "events": ["transaction.*"]
  }'

Save the returned id. Now create a subscription for the Ethereum address:

curl -X POST https://api.fluxrail.io/api/v1/subscriptions \
  -H "X-API-Key: flux_test_abc123" \
  -H "Content-Type: application/json" \
  -d '{
    "chain": "ethereum",
    "address": "0x742d35Cc6634C0532925a3b844Bc9e7595f2bD18",
    "webhook_id": "wh_abc123",
    "confirmations": 1,
    "events": ["native","erc20","erc721"]
  }'

Repeat for Polygon and Solana with their respective addresses. Each subscription returns an id you can use later to pause or delete.

Step 5: Handle Webhooks

When a transaction hits the monitored address, FluxRail sends a POST to your webhook URL with a JSON body and a signature in X-FluxRail-Signature. Verify the signature using HMAC-SHA256 with your webhook's secret (available in the dashboard). Example event payload:

{
  "id": "evt_xyz",
  "type": "transaction.mined",
  "chain": "ethereum",
  "address": "0x742d35Cc6634C0532925a3b844Bc9e7595f2bD18",
  "tx_hash": "0xabcd...",
  "value": "1.5",
  "token": "ETH",
  "from": "0x...",
  "to": "0x...",
  "confirmations": 1,
  "timestamp": "2025-03-01T12:00:00Z"
}

Your server should respond with 200 OK to acknowledge. FluxRail retries on failure.

Step 6: Query Event History

If you missed a webhook or need historical data, query events directly:

curl -s https://api.fluxrail.io/api/v1/events \
  -H "X-API-Key: flux_test_abc123" \
  -G -d 'chain=ethereum' -d 'address=0x742d35Cc6634C0532925a3b844Bc9e7595f2bD18' \
  -d 'limit=10' | jq '.'

You can filter by type, from, to, and date range. The response includes pagination metadata.

Step 7: Manage Subscriptions

List all your subscriptions:

curl -s https://api.fluxrail.io/api/v1/subscriptions \
  -H "X-API-Key: flux_test_abc123" | jq '.data[].id'

Toggle a subscription on/off without deleting:

curl -X POST https://api.fluxrail.io/api/v1/subscriptions/sub_abc123/toggle \
  -H "X-API-Key: flux_test_abc123"

Duplicate a subscription for a new address:

curl -X POST https://api.fluxrail.io/api/v1/subscriptions/sub_abc123/duplicate \
  -H "X-API-Key: flux_test_abc123" \
  -H "Content-Type: application/json" \
  -d '{"address":"0xnewaddress..."}'

Delete when no longer needed:

curl -X DELETE https://api.fluxrail.io/api/v1/subscriptions/sub_abc123 \
  -H "X-API-Key: flux_test_abc123"

Step 8: Validate Addresses

Before sending funds, validate the destination address:

curl -X POST https://api.fluxrail.io/api/v1/wallet/validate \
  -H "X-API-Key: flux_test_abc123" \
  -H "Content-Type: application/json" \
  -d '{
    "chain": "ethereum",
    "address": "0x742d35Cc6634C0532925a3b844Bc9e7595f2bD18"
  }'

Response: {"valid":true} or {"valid":false,"reason":"checksum mismatch"}.

Best Practices

• Use test mode first: All endpoints work with flux_test_ keys and simulate events. Verify your webhook handling before going live.
• Secure your webhook secret: Store it in environment variables. Verify every signature to prevent spoofing.
• Handle retries: FluxRail retries failed webhooks with exponential backoff. Idempotent processing is crucial.
• Monitor subscription health: Check webhook logs via GET /api/v1/subscriptions/{id}/webhook-logs for failures.
• Use confirmations: Set confirmations to 12 for Bitcoin, 1 for EVM chains to balance speed and finality.

Conclusion

With FluxRail's Core and Wallet services, you can monitor and manage multi-chain wallets without the overhead of running nodes or integrating multiple RPC providers. A single API key gives you real-time events, address derivation, validation, and subscription management across 36+ chains. Check the docs to explore more—like gas-free transfers with Pay or converting assets with Liquidity. Start building today with the Free plan.