Outpay Payments Glossary: Crypto, USDC, Base, and API Terms
Define the crypto payment, USDC, Base blockchain, checkout, API, wallet, webhook, and settlement terms used throughout Outpay Docs.
| Term | Definition |
|---|---|
| Base | The Ethereum layer-2 network used by the current payment matcher. |
| Checkout | A payment request and its hosted customer-facing flow. Also called a checkout session internally. |
| Checkout reference | The opaque identifier (chk_...) returned when a checkout is created. |
| Confirmation | Additional block depth confirmed after a transfer is included on-chain. |
| Currency | The token being transferred; v0.1 uses USDC exclusively. |
| Finality | Confidence that a transaction will not be reorganized off the canonical chain. Outpay's automated reorg handling is not verified. |
| Idempotency key | A merchant-generated key that lets checkout creation safely replay its original response instead of creating a duplicate. |
| Live mode | The API-key environment used for real, production-style merchant configuration. |
| Merchant webhook | A signed, outbound event delivered from Outpay to the merchant's server. |
| Non-custodial | Outpay does not hold funds; settlement is direct to the merchant's own wallet. |
| Overpayment | A transfer above the requested amount; a small tolerance is accepted, but remediation for a large overpayment is a beta concern — see payment lifecycle. |
| Payout wallet | The merchant-controlled address that receives every payment directly. |
| Test mode | The API-key environment intended for controlled integration testing. Not a separate blockchain sandbox. |
| Transaction hash | The blockchain identifier for a specific transfer. |
| Underpayment | A transfer below the requested amount. |
One canonical term per concept
This glossary uses one preferred term per concept throughout the documentation — for example, "payout wallet," not "withdrawal address" or "settlement wallet." If you see a synonym elsewhere, treat it as referring to the same thing defined here.
Related documentation
- Core concepts — the subset of these terms most relevant to a first integration.
- FAQ — short answers using this same terminology.
Outpay USDC Payments FAQ for Merchants and Developers
Get concise answers about Outpay custody, Base and USDC support, API integrations, payment links, webhooks, refunds, and beta readiness.
Outpay Support: Payment Issue Investigation Checklist
Prepare the checkout, transaction, API, and webhook evidence Outpay support needs to investigate a payment or integration issue safely.