Glossary
The vocabulary you'll meet integrating a gateway, in plain English. Every term links to a full explanation.
- FPX
- Financial Process Exchange, Malaysia's online-banking rail. The customer logs into their bank and approves the payment. Run by PayNet; almost every gateway supports it. Read more
- DuitNow QR
- The national interoperable QR standard. One QR code accepts most Malaysian bank apps and e-wallets. Read more
- E-wallet
- Stored-value apps like Touch 'n Go eWallet, GrabPay, Boost and ShopeePay. Gateways usually charge a separate e-wallet rate. Read more
- BNPL
- Buy Now, Pay Later: the customer pays in instalments (Atome, SPayLater, etc.) while you're paid upfront, minus a higher merchant fee. Read more
- MDR / discount rate
- Merchant Discount Rate: the percentage a gateway keeps per successful transaction. The headline 'fee' in the comparison table. Read more
- Settlement (T+1 / T+2)
- How many business days after a payment the money lands in your bank account. T+2 means two working days later. Read more
- Webhook / callback
- A server-to-server message the gateway sends your backend when a payment's status changes. It's the source of truth for whether you were actually paid, not the browser redirect. Read more
- Signature / checksum verification
- A cryptographic stamp (usually HMAC) on each callback proving it really came from the gateway and wasn't tampered with. Always verify it before trusting a webhook. Read more
- Idempotent settlement
- Processing the same paid event twice must not deliver the goods twice or double-count revenue. Key off the gateway's reference and ignore repeats. Read more
- Sandbox vs live
- Sandbox is a test environment with fake money and test keys. Live uses real money and production keys. Build and test in sandbox first; the two have separate credentials. Read more
- Tokenisation
- Replacing card details with a safe token so you can charge again later without ever storing the raw card number. Read more
- Recurring / subscription
- Automatically charging a saved payment method on a schedule (memberships, SaaS plans, instalments). Read more
- MCP
- Model Context Protocol: a standard that lets AI coding tools (Claude, Cursor, Codex) talk to a service's API directly. A gateway with an official MCP server is the easiest to wire up with an agent. Read more
- Agent skill
- A packaged instruction set that teaches an AI coding agent how to integrate a specific gateway correctly and securely. See the setup-* skills in the Build with AI agents section. Read more