Doxa proposes to evolve the collateral architecture of DoxaUSD from a model based on ckUSDC to a model in which the ultimate reserve asset is native USDY held by the Doxa Reserve on an EVM network.
The proposed architecture leverages the native Chain Fusion capabilities of the Internet Computer Protocol, including threshold ECDSA and the EVM RPC Canister, to allow Doxa’s reserve infrastructure to control and transact from an EVM address without relying on a traditional centralized custodian.
When a user deposits ICP to mint DoxaUSD, the protocol converts the ICP into ckUSDC as an intermediate settlement asset. The ckUSDC is then redeemed into native USDC on an EVM network. The Doxa Reserve uses the native USDC to acquire or subscribe for USDY. Once the USDY is confirmed as held by the Doxa Reserve, the Doxa Minter authorizes the corresponding DoxaUSD issuance.
The resulting flow is: ICP >ckUSDC > Native USDC > USDY > Doxa Reserve > DoxaUSD. This separates the settlement mechanism from the ultimate collateral asset.
1. Problem Statement
Settlement Asset vs. Reserve Asset. ckUSDC is useful for ICP settlement, but it is a representation of USDC within the ICP ecosystem. The proposed architecture separates ICP settlement from final collateralization: ICP ® ckUSDC ® USDC, followed by USDC ® USDY.
Reserve Utility. A reserve consisting exclusively of non-yield-bearing USDC does not inherently generate protocol-level reserve yield. USDY is designed as a yield-bearing tokenized asset, subject to issuer requirements, creating an opportunity for a reserve model in which underlying collateral can accrue value.
Cross-Chain Infrastructure. ICP Chain Fusion provides infrastructure for interacting with EVM networks. Doxa can therefore potentially operate an EVM reserve address controlled by an ICP canister through threshold cryptography.
2. Proposed Solution
Doxa proposes a Chain Fusion–native USDY Reserve Architecture. The Doxa Reserve Canister acts as the protocol-controlled reserve manager, maintaining an EVM address whose signing authority is derived from ICP threshold-ECDSA infrastructure.
The architecture consists of five major components: Doxa Minter; ICP Settlement Layer; EVM Reserve Controller; USDY Reserve; and DoxaUSD Ledger.
3. High-Level Architecture
USER > Doxa Minter > ckUSDC >Native USDC on EVM > USDY > Doxa Reserve > Collateral Verification > Doxa Minter > DoxaUSD Ledger > USER
4. Minting Process
Step 1 — User deposits ICP. A user initiates a DoxaUSD mint request. The Doxa Minter calculates the corresponding amount according to approved pricing and collateralization rules. No DoxaUSD is minted immediately.
Step 2 — ICP is converted to ckUSDC. The protocol converts the user’s ICP into ckUSDC. ckUSDC is treated as an intermediate settlement asset, not the final collateral.
Step 3 — ckUSDC is redeemed to native USDC. The ckUSDC position is redeemed into native USDC on the selected EVM network, with the Doxa Reserve EVM address as the destination.
5. USDY Acquisition
Once native USDC reaches the Doxa Reserve, the protocol initiates conversion from USDC into USDY. Depending on the final integration and issuer requirements, this may occur through direct subscription or secondary-market acquisition.
The implementation must account for USDY eligibility requirements, jurisdictional requirements, available liquidity, smart-contract interfaces, transaction costs, redemption mechanisms and operational risk.
The protocol invariant remains: DoxaUSD is not minted until the corresponding USDY collateral is verifiably held by the Doxa Reserve.
6. Chain Fusion Reserve Control
The Doxa Reserve is designed to be controlled by an ICP canister rather than by an individual private key. The architecture uses ICP Chain Fusion capabilities. The EVM RPC Canister provides access to the relevant EVM network, while the reserve canister can construct transactions and request threshold signatures for authorized operations.
7. Reserve Verification
Before DoxaUSD is issued, the protocol must establish that the expected collateral exists. Verification should include EVM transaction confirmation, destination-address verification, USDY contract verification, token-balance verification, transaction-receipt verification, acquisition/subscription verification, applicable valuation and collateralization checks.
Only after these checks succeed should a mint request move from PENDING to COLLATERAL VERIFIED and subsequently MINTED.
8. DoxaUSD Minting Invariant
The core protocol invariant should be: Every DoxaUSD unit in circulation must be backed by the protocol’s defined amount of verified USDY collateral held by the Doxa Reserve, subject to approved collateralization and valuation rules.
9. DoxaUSD Redemption
A user burns DoxaUSD to request redemption. Conceptually: DoxaUSD > Doxa Minter >USDC > ICP-side settlement > ckUSDC > ICP > User.
The precise redemption mechanism will depend on the final EVM and ICP settlement implementation. The protocol should maintain a deterministic relationship between DoxaUSD supply, reserve collateral and redemption capacity.
10. Yield Treatment
USDY is a yield-bearing reserve asset. Doxa should establish through DAO governance how reserve yield is treated without automatically changing the target denomination of DoxaUSD.
Possible models include reserve accumulation, protocol sustainability, Doxa ecosystem allocation, or a hybrid model. Any allocation should be subject to explicit DAO governance.
11. Why USDY Changes the Doxa Architecture
The proposed architecture transforms DoxaUSD from a stablecoin backed by an ICP-side representation of USDC into a stablecoin whose ultimate reserve can exist natively in the broader EVM tokenized-asset ecosystem.
ICP becomes the user entry layer; ckUSDC becomes the settlement layer; native USDC becomes the EVM settlement asset; USDY becomes the reserve asset; and DoxaUSD remains the ICP-native stablecoin.
12. Chain Fusion as Core Infrastructure
The architecture demonstrates a broader use case for ICP Chain Fusion: Doxa can use ICP canisters as the protocol control layer while interacting directly with EVM networks, potentially enabling native EVM asset custody, programmable reserve management, automated transactions, on-chain reserve verification, DAO-controlled treasury operations and cross-chain settlement.
13. Reserve Transparency
Doxa should publish the EVM reserve address publicly. Users should be able to independently verify USDY balance, USDC balance, reserve transactions, USDY acquisition transactions, redemption transactions, DoxaUSD supply, collateralization ratio and reserve movements.
The Doxa dashboard should ultimately reconcile DoxaUSD supply against the protocol reserve.
14. Security Architecture
The proposed implementation should introduce multiple layers of protection: canister-controlled reserve; threshold ECDSA; whitelisted contracts; transaction limits; rate limits; emergency controls; and independent reserve verification.
15. Oracle and Valuation Requirements
Because USDY is a yield-bearing asset, Doxa must define how collateral value is calculated. The system should specify USDY/USD price source, update frequency, acceptable deviation, stale-price threshold, fallback mechanism, emergency valuation procedure and collateralization threshold.
The protocol should distinguish token balance from USD value: USDY Balance × Approved USDY Valuation = Reserve Value.
16. Initial Network Strategy
The initial implementation should target a single EVM network to minimize operational complexity. Ethereum can serve as the initial reserve network where the required USDY infrastructure and liquidity are available. Future expansion can consider additional supported networks after technical, liquidity, issuer and governance requirements are satisfied.
17. ICRC Integration
DoxaUSD remains an ICP-native token. ICRC standards govern ICP-side token and consent interactions. ICRC-21 should be considered for applicable user-consent flows; it should not be treated as the standard defining USDY itself. EVM token standards govern native USDY and USDC, while Chain Fusion connects the ICP protocol layer with EVM execution.
18. Proposed Transaction State Machine
REQUESTED > ICP RECEIVED > CKUSDC ACQUIRED > USDC REDEEMED > USDC RECEIVED > USDY ACQUIRED > USDY VERIFIED > COLLATERAL VERIFIED > DOXAUSD MINTED
Any failed stage should prevent DoxaUSD minting. For example, if USDY is not received, minting remains blocked.
19. Failure Scenarios
The system should explicitly handle failures including ICP-to-ckUSDC failure, ckUSDC-to-USDC failure,
USDC-to-USDY failure, USDY verification failure, EVM RPC failure, price-oracle failure and USDY contract risk. Each should have defined retry, pause, refund or governance-controlled recovery procedures.
20. Governance
The transition should be implemented through Doxa DAO governance. Governance should approve at minimum: USDY as an approved collateral asset; approved USDY contract; EVM reserve network; reserve controller; maximum issuance; collateralization requirements; valuation methodology; reserve transaction limits; emergency controls; yield allocation policy; redemption mechanisms; and approved liquidity venues.
21. Migration Strategy
Phase 1 — Research: validate USDY availability, eligibility, legal requirements, smart-contract interfaces, EVM support, liquidity, redemption and accounting.
Phase 2 — Testnet: deploy the Doxa Reserve test canister, EVM integration, monitoring, USDY accounting, reserve verification and minting state machine without production funds.
Phase 3 — Controlled Mainnet Pilot: introduce a limited USDY collateral capacity with DAO-defined limits.
Phase 4 — Public Reserve Transparency: publish reserve address, contract addresses, balances, transaction history, DoxaUSD supply and collateralization data.
Phase 5 — DAO Migration: following successful validation, governance determines whether USDY becomes the primary DoxaUSD collateral asset.
22. Proposed End-State
ICP > ckUSDC > Native USDC > Native USDY > Doxa Reserve > DoxaUSD
The reserve controller is an ICP canister using Chain Fusion and threshold ECDSA to control the EVM reserve address.
23. Strategic Significance
The proposed architecture positions DoxaUSD as an ICP-native stablecoin capable of interfacing directly with tokenized real-world assets outside the ICP ecosystem. The key innovation is the separation of ICP-native user experience from EVM-native reserve infrastructure.
This creates a foundation for multi-chain stablecoins, tokenized real-world assets, agentic payments, automated treasury management, cross-chain settlement, programmable reserves, institutional liquidity and AI-agent payments.
