BitPay Integration: Accept Crypto Payments via API

Integrating a crypto payment gateway into e-commerce is more than just plugging in an SDK. We often encounter situations where after creating an invoice, the webhook doesn't arrive or statuses get duplicated, and the accounting department can't reconcile. BitPay solves these issues, but requires proper status handling and idempotency.

We integrate BitPay into your business: configure acceptance of BTC, ETH, USDC, USDT via Ethereum, Polygon, Arbitrum, Base. BitPay takes care of legal documentation and fiat conversion. Our team has completed 25+ cryptocurrency integrations. BitPay is 3 times faster to set up than a custom gateway. We'll evaluate your project for free — contact us.

How Does the Payment Flow Work?

The API works through invoices: your backend creates an invoice on BitPay, gets a URL to redirect the user, BitPay accepts payment and notifies your webhook. Full documentation is available in BitPay API Reference.

Why Is ECDSA Authentication More Complex Than an API Key?

BitPay signs requests with a private key instead of a static token. This is more secure, but requires generating an ECDSA keypair and registering the public key as a token.

For most integrations, it's easier to use the official BitPay SDK (Node.js, PHP, Python, Ruby, Java) — it encapsulates request signing.

const BitPaySDK = require('bitpay-sdk');
const fs = require('fs');

async function setupBitPay() {
    const client = new BitPaySDK.Client(
        null,
        BitPaySDK.Env.Prod,
        fs.readFileSync('./private.key', 'utf8')
    );
    
    await client.authorizeClient('your-pairing-code');
    return client;
}

Creating an Invoice

const BitPaySDK = require('bitpay-sdk');

async function createInvoice(orderId, amount, currency = 'USD') {
    const invoice = new BitPaySDK.Models.Invoice(amount, currency);
    
    invoice.orderId = orderId;
    invoice.notificationUrl = `https://yourapp.com/webhooks/bitpay`;
    invoice.redirectUrl = `https://yourapp.com/orders/${orderId}/success`;
    invoice.closeUrl = `https://yourapp.com/orders/${orderId}/cancel`;
    
    invoice.buyer = new BitPaySDK.Models.Buyer();
    invoice.buyer.email = customerEmail;
    
    const created = await client.createInvoice(invoice);
    return {
        invoiceId: created.id,
        paymentUrl: created.url,
        expirationTime: created.expirationTime
    };
}

An invoice is valid for 15 minutes by default — the user must pay within that period. The amount in USD is fixed at the BitPay exchange rate at the moment of invoice creation.

Webhook Handling

BitPay sends an IPN (Instant Payment Notification) to the notificationUrl. It is critical to verify the invoice status via the API, not just trust the webhook body.

const express = require('express');
const router = express.Router();

router.post('/webhooks/bitpay', async (req, res) => {
    const { id: invoiceId, status } = req.body.data || {};
    
    if (!invoiceId) {
        return res.status(400).json({ error: 'Missing invoice ID' });
    }
    
    const invoice = await client.getInvoice(invoiceId);
    
    switch (invoice.status) {
        case 'paid':
            await updateOrderStatus(invoice.orderId, 'paid_unconfirmed');
            break;
        case 'confirmed':
            await updateOrderStatus(invoice.orderId, 'confirmed');
            break;
        case 'complete':
            await fulfillOrder(invoice.orderId);
            break;
        case 'expired':
            await updateOrderStatus(invoice.orderId, 'expired');
            break;
        case 'invalid':
            await handleInvalidPayment(invoice.orderId, invoice);
            break;
    }
    
    res.json({ success: true });
});

For fulfillment, use confirmed or complete depending on your risk tolerance. complete is safest but has a longer delay.

Refunds

BitPay requires a return address — you need to request it from the user at the time of payment or when initiating a refund.

async function createRefund(invoiceId, amount, currency) {
    const refund = new BitPaySDK.Models.Refund();
    refund.invoiceId = invoiceId;
    refund.amount = amount;
    refund.currency = currency;
    
    const created = await client.createRefund(refund);
    return created;
}

Risks Covered by BitPay

BitPay handles transaction security, guarantees no chargebacks (irreversible payments), and provides certified reports for accounting. According to official documentation, the platform does not require additional regulatory approval.

Comparison: BitPay vs. Custom Gateway

Typical Integration Issues

Webhook not arriving. BitPay requires HTTPS with a valid certificate on the notificationUrl. Localhost is not accessible — for development use ngrok or BitPay Testnet with a public URL.

Duplicate webhooks. BitPay may send multiple notifications for the same status (retry on timeout). Use invoiceId as an idempotency key: INSERT ... ON CONFLICT (invoice_id, status) DO NOTHING.

Partial payment. If the user pays less, the status becomes invalid. BitPay automatically returns the underpayment if the buyer's email is available.

Timezone in expirationTime. The field is returned as a Unix timestamp in milliseconds. new Date(invoice.expirationTime) — remember it's milliseconds, not seconds.

Testing

BitPay provides a Testnet environment (BitPaySDK.Env.Test) with test Bitcoin. Create an invoice, pay with a testnet wallet — the entire flow without real money. The pairing code for the test environment is created separately in the dashboard.

What's Included in the Work

1. BitPay SDK integration (Node.js, PHP, Python, Ruby, Java)
2. Idempotent webhook endpoint setup
3. Status handling and edge cases (expired invoice, partial payment, retry)
4. Testnet testing and deployment
5. Documentation of your implementation
6. 30 days of post-launch support

Estimated Timeline

2–3 days: 1 day for SDK, 1 day for webhook + state machine, 1 day for testing. The exact cost is calculated individually based on integration complexity. Get a consultation — contact us for a project evaluation. Order a BitPay integration, and we'll configure crypto acceptance within 48 hours.

Blockchain Infrastructure Deployment: Nodes, RPC, Indexing

Subgraph fell at 3:47 AM. By morning users saw outdated balances, transactions "hung" in the UI, support received 47 tickets in an hour. Cause: the handler in the subgraph failed on a transaction with a non-standard event log — and the entire index stopped. We have encountered such situations dozens of times. Our experience shows: blockchain infrastructure does not forgive gaps in observability. Guaranteeing uptime without multi-layered monitoring and fault-tolerant architecture is impossible. Over 8 years working with Ethereum, Polygon, and Solana, we have developed an approach that allows predictable deployment of infrastructure of any scale — from a single node to a multichain grid with dozens of subgraphs.

RPC Layer Architecture

Every dApp interaction with the blockchain goes through RPC — the JSON-RPC API provided by a node. Three options:

Managed providers — Alchemy, QuickNode, Infura, Ankr. Minimal operational costs, SLA, built-in monitoring. Limits: rate limits (Alchemy Free: 300 RU/sec), vendor lock, potential downtime during provider incidents. For most projects — the right choice at the start.

Self-owned nodes — full control, no rate limits, no third-party dependence. Cost: archive Ethereum node requires 2.5–3TB SSD, a strong server, and DevOps support. Sync from scratch on Ethereum via Geth/Nethermind — 3–7 days. Justified under high load or latency requirements.

Hybrid — self-owned node as primary, managed provider as fallback. Standard for protocols with high TVL. Proper load balancing can reduce costs by 20–30% compared to pure managed setup. Under high monthly request volume, hybrid saves significantly.

How to Set Up an RPC Layer Without a Single Point of Failure?

At least two providers, DNS round-robin with health check every 5 seconds, automatic fallback when latency >500 ms. In practice, this gives 99.99% availability during any provider failure. For protocols with high TVL, we recommend a custom HA-proxy (nginx or Envoy) in front of two managed providers.

Why Is a Hybrid RPC Scheme More Cost-Effective Than Pure Managed?

At high request volumes, managed providers can be very expensive; a hybrid using a self-owned node as primary and a managed fallback cuts costs significantly without losing SLA.

Ethereum Node Clients

Execution clients: Geth (most used), Nethermind (C#, fast sync), Besu (Java, enterprise), Erigon (fastest sync, efficient archive mode ~2TB instead of 3TB).

Consensus clients (post-Merge): Lighthouse (Rust), Prysm (Go), Teku (Java), Nimbus (Nim). Each node after The Merge requires a pair of execution + consensus clients.

For DevOps: eth-docker — Docker Compose configurations for all client combinations. Setting up monitoring via Grafana + Prometheus is mandatory; a standard dashboard is available in each client's repository.

The Graph: Event Indexing

The Graph Protocol — decentralized indexing. A subgraph describes which events from which contracts to index and how to transform them into a GraphQL schema.

Subgraph structure:

• subgraph.yaml — manifest: contract addresses, startBlock, events to handle
• schema.graphql — GraphQL schema of entities
• src/mapping.ts — AssemblyScript event handlers

dataSources:
  - kind: ethereum
    name: UniswapV3Pool
    network: mainnet
    source:
      address: "0x88e6A0c2dDD26FEEb64F039a2c41296FcB3f5640"
      abi: UniswapV3Pool
      startBlock: 12370624
    mapping:
      eventHandlers:
        - event: Swap(indexed address,indexed address,int256,int256,uint160,uint128,int24)
          handler: handleSwap

AssemblyScript handlers — not TypeScript. No nullable types, no closures, no many standard APIs. An error in the handler stops the subgraph indexing on that transaction. Important: add try-catch for operations that can fail (e.g., store.get() for an entity that may not exist).

How to Avoid Subgraph Indexing Stops?

Graph Node logs are monitored in real-time; on hasIndexingErrors = true an alert fires and an automatic node restart (via systemd or Kubernetes). Typical downtime on error — 150–300 seconds to recover. Additionally, for production we set up a watchdog that restarts Graph Node if subgraph lag exceeds 50 blocks.

Choosing Between Hosted Service and Decentralized Network

Graph Hosted Service (free, centralized) is deprecated in favor of Subgraph Studio + Graph Network. For production: deploy on Graph Network with GRT curation signal — the subgraph gets indexers proportional to curation.

Alternatives to The Graph: Ponder (TypeScript, self-hosted, easier to debug), Envio (ultra-fast indexer, supports EVM + non-EVM), Subsquid (TypeScript, own network), Moralis Streams (managed, webhook-based). Our experience shows: for high-load projects with unique logic, Ponder or Envio are more effective — they give full control over the process and do not require GRT tokenomics.

Webhooks and Real-Time Notifications

Alchemy Webhooks and QuickNode Streams allow receiving events in real-time via HTTP webhook or WebSocket. For monitoring addresses, new transactions, mints — this is faster than polling RPC.

Tenderly — platform for monitoring and alerts. You can set up an alert for a specific contract event, balance change, function call with certain parameters. Transaction simulation via Tenderly API is invaluable for debugging.

Monitoring and Observability

Minimum monitoring stack for a protocol:

On-chain: OpenZeppelin Defender Sentinel — watches contract events, triggers webhook or Autotask when conditions are met. Forta Network — community-maintained bots detect anomalies (large withdrawals, flash loans, governance attacks).

Infrastructure: Grafana + Prometheus for nodes, Datadog or Grafana Cloud for managed metrics. Alerts on: node is 10+ blocks behind, RPC latency >500ms, subgraph lag >100 blocks.

Uptime: Better Uptime or PagerDuty on RPC endpoint and subgraph health endpoint (The Graph provides _meta { hasIndexingErrors, block { number } }).

Why Is Monitoring Without Tenderly Insufficient?

Tenderly provides transaction simulation and detailed traces — critical for debugging subgraph and smart contract errors. Forta focuses on network anomalies, not your infrastructure. The combination of Tenderly plus a custom Grafana dashboard covers 90% of incident scenarios.

Multichain Infrastructure

A protocol on 5 chains = 5 separate RPC endpoints, 5 subgraphs, 5 monitoring configs. Manageable but requires deployment automation.

For subgraph multi-network deployment: graph deploy --network mainnet, graph deploy --network arbitrum-one etc. with a unified codebase and network-specific addresses in separate config files.

Chainlink CCIP and LayerZero for cross-chain messaging require monitoring of both chains and transactions on intermediate relayers. A reorg on the source chain after a confirmed mint on the target chain is a classic bridge problem. Solution: wait for finality (on Ethereum ~15 minutes after Merge for economic finality) before confirming on the target chain.

Infrastructure Setup Process

1. Audit current stack — determine chains, request volume, latency and availability requirements.
2. Architecture design — select providers, load balancing, redundancy.
3. Subgraph development — manifest → schema → handlers → testing on local Graph Node → deploy to testnet → mainnet.
4. Monitoring configuration — Tenderly alerts, Grafana dashboard, PagerDuty integration.
5. Documentation and runbook — what to do when: subgraph falls behind, RPC downtime, node desync.
6. Handover to operations — team training, access transfer, first month support.

What's Included

• Deployment of managed or self-hosted Ethereum, Polygon, BNB Chain nodes
• RPC layer setup with primary/fallback and load balancing
• Subgraph development and deployment for your protocol
• Monitoring connection (Tenderly, Grafana, alerts)
• Runbook and operations documentation
• Team training (up to 4 hours online)
• 30-day support after delivery

Timeline

All projects are managed in a GitHub/GitLab repository with CI/CD; configuration code stays with you. Order infrastructure deployment — we'll show how to cut costs by 20–30% without losing reliability. Get a consultation — we'll demonstrate how we deployed infrastructure for a protocol with large TVL on Ethereum and Arbitrum. Contact us.