System Design

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Architectural Summary

CashmereLabs operates a dual-layer architecture that combines:

• On-chain execution written in Solidity, Move, and Anchor to govern burn, attestation, mint, yield routing, and policy enforcement.
• Autonomous relayers implemented in Go that handle pricing, attestation retrieval, compliance, and settlement orchestration across EVM and non-EVM networks.

Together, these layers deliver deterministic, zero-slippage mobility for stablecoins while powering autonomous yield, privacy-preserving settlement, and fiat ↔ crypto connectivity.

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On-Chain Components

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CashmereCCTP (EVM)

• Verifies relayer-signed fee quotes (ECDSA).
• Executes burns, emits verifiable events, and enforces minimum output guarantees.
• Supports transfer, transferV2, and permit variants for gas-optimised execution.

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Move / Anchor Modules (Sui, Aptos, Solana)

• Mirror the burn → attest → mint lifecycle using Ed25519 signature schemes.
• Integrate chain-native fee handling and deterministic finality.

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Smart Account Infrastructure (ERC-4337)

Built on ERC-4337 account abstraction with specialised validator modules:

• Smart Accounts: Users interact via programmable, non-custodial accounts.
• Validator Modules: Authenticate relayer/yield-agent actions under cryptographic policies.
• Session Keys: Grant scoped authority for bridging, yield allocation, or ramp transfers without exposing primary keys.
• Programmable Policies: Enterprises define limits (e.g., max transfer size, approved protocols, scheduling windows).

This transforms static wallets into autonomous smart accounts—enabling safe delegation to agents while users retain full asset control.

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Cross-Chain Execution Model

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Autonomous Relayers

Relayers are stateless orchestration agents. They never custody user funds; instead they validate events, quote fees, and submit destination transactions.

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Runtime Capabilities

• Subscribe to burn events across supported chains.
• Estimate fees using issuer feeds, on-chain gas data, and Cashmere policy limits.
• Sign quotes (ECDSA/Ed25519) with ≈100-second expiries.
• Retrieve and verify attestations from Circle CCTP, Tether USDT0, and future issuers.
• Submit destination mints with nonce management and retry logic.
• Enforce per-chain policy hooks (allowlist/denylist, AML checks).
• Provide observability via Prometheus metrics, structured logging, and circuit breakers.

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Execution Flow

1. Detect Burn – listen for CashmereTransfer (or equivalent) events on the origin chain.
2. Retrieve Attestation – fetch issuer proofs and validate signatures.
3. Mint & Finalise – submit the destination mint, enforcing min finality thresholds (1,000 Fast / 2,000 Normal).
4. Record & Monitor – persist transaction data and expose it through the Monitoring API for analytics.

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Fee Quotation Pipeline

• Clients call GET /getEcdsaSig_native or GET /getEd25519Sig_native.
• Relayers compute destination gas, issuer cost, and policy-defined overhead.
• Response includes fee, deadline, and signature.
• Users embed these values when invoking on-chain contracts.
• Quotes expire after ~100 seconds to keep pricing aligned with live network conditions.

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Yield Agent Layer

On top of the transfer infrastructure, Cashmere deploys autonomous agents that turn idle stablecoins into self-optimising capital:

• Continuous monitoring of APRs across integrated venues (Morpho, Euler, Jupiter).
• Policy-driven allocation using user-approved session keys (no custody risk).
• Cross-chain rebalancing via the same zero-slippage transfer fabric.
• Transparent reporting and withdrawal optionality at all times.

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Privacy & Compliance Layer

The forthcoming Cashmere Privacy module introduces zk-based settlement with optional selective disclosure:

• Confidential transfers for users and DAOs.
• Audit trails and disclosure hooks for regulated institutions.
• Integration with policy engines to maintain KYC/AML compatibility.

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Reliability & Security

For detailed contract interfaces and APIs, see Smart Contracts and Backend APIs.