Protocol Design
At the heart of Epay lies a stablecoin-powered settlement protocol that transforms the way money moves globally. Instead of relying on fragmented correspondent banking networks, Epay uses widely adopted, transparent, and liquid stablecoins such as USDC, USDT, and PYUSD as the foundation of cross-border value transfer. These assets ensure price stability, predictable settlement, and interoperability across multiple blockchains.
Stablecoins as the Settlement Layer
Stablecoins function as neutral payment instruments within Epay. When a user initiates a transfer, their local fiat currency is converted into a stablecoin at the best available rate. This stablecoin then travels across Epay’s settlement network, bypassing traditional banking delays, and is redeemed for local fiat at the destination. By using stablecoins, Epay achieves:
Instant settlement with finality on-chain.
Lower fees by removing costly intermediaries.
Transparency via verifiable on-chain transactions.
Resilience through multi-chain support and asset redundancy.
Transaction Flow
The movement of funds within Epay is designed to abstract blockchain complexity while ensuring compliance, efficiency, and finality of settlement. The flow can be broken into four distinct phases:
1. Fiat On-Ramp
When a user initiates a transaction, Epay provides multiple fiat funding rails, including bank transfers, card payments, and mobile money integrations. Each on-ramp request is linked to the user’s verified identity through KYC/AML checks executed by Epay or its local anchor partners. Once verified, the fiat deposit is tokenized into a stablecoin-equivalent balance within the Epay system.
Process:
User selects funding method (bank → USDC, card → PYUSD, etc.).
Payment is authorized and recorded in fiat.
The backend triggers a stablecoin acquisition event.
Technical considerations:
Fiat custody handled by regulated anchors/payment processors.
API callbacks confirm settlement before stablecoin issuance.
Anti-fraud checks and transaction monitoring at the point of entry.
2. Conversion
Once fiat funds are confirmed, Epay mints or sources stablecoins (USDC, USDT, PYUSD) through liquidity providers and exchanges. Conversion occurs either via:
Direct issuance – minting from authorized stablecoin issuers (e.g., Circle for USDC).
Secondary market sourcing – acquiring stablecoins via on-chain DEXs or centralized exchanges.
To optimize user experience, Epay uses a real-time FX quoting engine inspired by Stellar SEP-38. Users are shown the conversion rate upfront, and once confirmed, the system locks the rate to protect against slippage.
Technical considerations:
Oracle feeds supply real-time fiat/stablecoin exchange rates.
Liquidity routing algorithm selects the best source (on-chain vs. off-chain).
Stablecoin custody is immediately assigned to the user’s wallet balance.
3. Settlement
Stablecoins serve as the neutral settlement currency across borders. Instead of routing through correspondent banks, funds move through blockchain networks (Ethereum L2s, Solana, Stellar, etc.).
Process:
Stablecoins are transferred peer-to-peer between wallets or treasury accounts.
Settlement finality occurs once the transaction is confirmed on-chain.
Technical considerations:
Multi-chain routing ensures flexibility (user chooses cheapest/fastest rail).
Transactions use multi-sig or MPC signing for security.
Batch settlement available for enterprise clients to reduce gas fees.
Hash-linked proofs can be used to reconcile off-chain fiat with on-chain stablecoin flows.
4. Fiat Off-Ramp
At the destination, the recipient requests withdrawal to their local fiat account. This step is managed by anchors, who convert the stablecoin into the appropriate fiat and disburse via local rails (bank transfer, mobile money, cash pickup).
Process:
Recipient specifies cash-out method.
Stablecoins are transferred from Epay’s treasury/anchor pool to the off-ramp partner.
Local fiat is released to the recipient.
Technical considerations:
Off-ramp partners must be regulated payment institutions.
Compliance enforcement ensures AML coverage in both jurisdictions.
Settlement confirmation is logged both on-chain and in off-chain ledgers for auditability.
End-to-End Flow
This fiat → stablecoin → cross-border → fiat model ensures:
Interoperability between fiat systems and blockchain.
Reduced counterparty risk by minimizing dependence on correspondent banks.
Transparency with verifiable on-chain transactions.
User simplicity, as blockchain mechanics are hidden behind APIs and app interfaces.
By fusing traditional finance access points (on/off-ramps) with stablecoin-based settlement, Epay creates a programmable financial layer where transactions can be executed, audited, and scaled globally.
Anchors and Partners
To achieve last-mile connectivity, Epay integrates with anchors—regulated financial institutions, mobile money operators, and payment processors that facilitate fiat entry and exit. Anchors handle:
Cash-in: accepting deposits in local currencies.
Cash-out: processing withdrawals to banks, wallets, or mobile accounts.
Compliance: executing KYC/AML checks in line with local laws.
By leveraging a global network of anchors, Epay ensures its users can access services in over 100 countries without requiring direct banking integrations in each jurisdiction.
Governance & Upgradeability
Epay’s protocol is designed for progressive decentralization while maintaining compliance. Governance is managed through a hybrid model:
Core Team Oversight: initial upgrades, security patches, and feature rollouts.
Partner & Community Input: anchors, businesses, and developers participate in governance proposals.
On-Chain Governance (Future): token-weighted voting may be introduced for protocol upgrades, treasury allocation, and ecosystem incentives.
The protocol supports modular upgradeability, allowing the integration of new blockchains, assets, and compliance frameworks without disrupting existing services. This ensures that Epay remains future-proof in a rapidly evolving payments landscape.
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