Crypto payment gateway development comes down to four design decisions made before any code: how merchants and shoppers check out, who holds the keys, which assets and networks you settle in, and how you meet the compliance rules that apply to you. Stablecoins have made crypto checkout practical for many businesses, but a gateway that gets custody or reconciliation wrong can lose funds quietly and permanently.
If you are scoping a gateway for your platform or merchants, share your use case with us and we will map the architecture choices that apply.
The merchant checkout flow, step by step
From the shopper's side a crypto payment looks simple: choose a coin, scan a QR code, confirm in a wallet. Underneath, the gateway coordinates several steps:
- Invoice creation: the merchant's store calls your API with the order amount; the gateway creates an invoice with an expiry window.
- Quote: for volatile assets, the gateway converts the fiat order value into a crypto amount and locks that quote for a short period.
- Payment address or reference: each invoice gets a unique deposit address, derived from an HD wallet, or a unique on-chain reference, so incoming funds can be matched to the right order.
- Detection and confirmation: nodes or indexers watch for the payment and wait for the confirmation depth set for each chain before marking it final.
- Notification: the gateway sends a signed webhook to the merchant, who releases the goods.
The edge cases that decide quality
Real payments are messy. Plan explicitly for underpayments, overpayments, payments arriving after the quote expires, two transactions for one invoice, the right token sent on the wrong network and chain reorganizations that undo an apparently confirmed transaction. Each needs a defined state, a merchant-facing message and a resolution path, including refunds.
Wallet and custody design
Custodial versus non-custodial
In a custodial model the gateway receives funds into wallets it controls and later settles to merchants. This allows conversions, consolidated payouts and a smoother merchant experience, but makes you responsible for safeguarding customer assets and brings heavier regulatory obligations. In a non-custodial model, payments go straight to wallets the merchant controls and the gateway only tracks and verifies them. It carries less custody risk but offers fewer features.
Protecting keys in a custodial setup
- Split funds across hot wallets for daily operations and cold or warm storage for reserves.
- Use MPC (multi-party computation) or hardware security modules so no single server or person holds a complete key.
- Sweep deposit addresses into treasury wallets on a schedule, with gas management for token transfers.
- Require multiple approvals and allowlisted destinations for large withdrawals.
Our guide to crypto wallet development goes deeper into key management and wallet architecture.
Stablecoin settlement
Most merchants do not want price exposure. Stablecoins such as USDC and USDT remove most of the volatility between checkout and settlement, and many gateways now default to them.
Network choice matters
The same stablecoin exists on several networks, including Ethereum, its layer 2s, Tron, Solana and others, each with different fees and confirmation times. Supporting too many networks confuses shoppers and multiplies operational work; supporting too few loses customers. Show the network clearly at checkout and reject or flag deposits on unsupported networks.
Settlement options for merchants
Merchants may want to keep stablecoins, receive them in a wallet of their choice, or convert to fiat through a licensed exchange or payout partner. Each route has its own operational and compliance steps. For teams considering their own stable asset, see our article on stablecoin development.
Compliance considerations in India
Crypto is not legal tender in India, but businesses dealing in virtual digital assets (VDAs) operate under a specific framework. Service providers that exchange, transfer or safeguard VDAs on behalf of others are treated as reporting entities under the Prevention of Money Laundering Act and must register with the Financial Intelligence Unit (FIU-IND). That brings duties such as KYC of customers, record keeping and suspicious transaction reporting.
India also taxes gains on VDA transfers under a dedicated regime and applies tax deduction at source on many transfers, which affects how merchants and the gateway account for each payment. Cross-border flows can raise foreign exchange questions as well.
Rules change, and whether your model counts as a reporting entity depends on its details. Involve legal and tax advisors early; the technical architecture should then support what they require, including merchant onboarding (KYB), sanctions screening, blockchain analytics for risky funds and audit-ready transaction records.
What crypto payment gateway development involves
A production gateway typically includes a merchant API with idempotent requests, signed webhooks, a merchant dashboard, e-commerce plugins, chain watchers or indexer integrations per network, a ledger that records every movement in double-entry form, a treasury service, an admin console for support and compliance teams, and monitoring that alerts on stuck payments or unusual withdrawals.
iJurug Soft builds blockchain and fintech systems, including wallets, smart contracts and payment flows, with senior engineers on every engagement and security designed in from the start. Work moves through fixed milestones, usually beginning with one network and one stablecoin before expanding. If your gateway sits inside a broader product, our fintech app development work covers the surrounding app.
Frequently asked questions
Should we start custodial or non-custodial?
Many teams start non-custodial to launch with less regulatory and security burden, then add custodial features once demand and compliance readiness are clear.
Which coins should we support first?
Usually one or two widely held stablecoins on networks your target customers already use. Add more based on real requests rather than guesses.
How do refunds work in crypto?
Transactions cannot be reversed, so refunds are new outgoing payments. The gateway needs a verified refund address and an approval flow for each one.
Can you integrate with our existing store or app?
Yes, through a REST API, webhooks and plugins for common e-commerce platforms, or a custom integration for your own checkout.
Planning to accept or process crypto payments safely? Tell us about your merchants, markets and timeline through our contact form, or write to info@ijurugsoft.com. We will respond with a suggested architecture and a clear quote.