Using Cadence

“It’s not about piling on more and more features — it’s about making the UX effortlessly simple so everyday users never get stuck or overwhelmed.”

Estate planning is already an emotional and intimidating topic. When an everyday retail investor or a grieving heir arrives at Cadence, the last thing they want is cryptic cryptographic steps, confusing 20-word forms, or technical friction. Every design decision in Cadence feels as smooth, clear, and reassuring as a modern consumer fintech application:

Zero Crypto Jargon

Clean, plain English throughout the entire app (“Deposit with 1 Click”, “Unlock Allocation”, “Unlock Inherited Box”) with intuitive presets (5-minute testing vs. 180-day standard) instead of raw technical configurations.

Assisted QR Funding

No manual contract copy-pasting or cross-chain bridge anxiety. Users simply scan with Coinbase, Binance, Kraken, or mobile Web3 wallets, confirm with native FaceID / TouchID, and funding is complete.

1-Click Atomic Deployment

Behind the scenes, OneClickInheritanceVault.sol deploys an Aave-connected vault, configures Proof-of-Life consensus, and registers guardians in a single wallet transaction.

Zero-Password Claiming

Heirs never have to hunt for master passwords or recovery phrases. Connecting their wallet and clicking “Unlock Allocation” handles in-browser mathematical decryption silently in seconds.

The core protocol primitives governing automated proof-of-life, privacy protection, and estate streaming:

Proof-of-Life Heartbeat

The periodic on-chain check-in interval (e.g. 90, 180, or 365 days). Calling checkIn() resets the countdown timestamp and confirms owner activity.

Guardian Quorum

A 2-of-3 threshold consensus managed by GuardianRegistry.sol. Guardians only attest to incapacitation after a heartbeat lapse; individual guardians cannot execute alone.

14-Day Grace Period

A mandatory buffer initiated after quorum. The owner receives automated sentinel alerts and can dismiss false-alarm claims gaslessly with an off-chain EIP-712 typed signature.

Blinded Merkle Root

Heir public keys and percentage splits are double-hashed client-side into allocationRoot. Zero plaintext heir identities or balances ever touch on-chain storage.

Cadence Streams

Autonomous streaming trusts releasing an immediate 10% emergency buffer, streaming the remaining 90% second-by-second to prevent phishing drainers and estate dumping.

Aave v3 Yield Engine

Unvested streaming balances deposit directly into Aave v3 on Arbitrum Sepolia, generating borrower-paid interest with zero cross-chain bridge exposure.

Anti-Drainer Defense

Appointed guardians or verified backup cold wallets can call pauseStream() and redirectStream() if an heir wallet is compromised.

Off-Chain Legacy Box

Hybrid AES-256-GCM + ECIES envelope encryption allowing benefactors to attach centralized exchange accounts, 1Password master keys, and hardware seed shards pinned to IPFS and anchored on-chain with zero disk persistence.

Live 2FA Google Authenticator

Client-side RFC-6238 TOTP computation that generates synchronized 6-digit Google Authenticator codes in browser RAM, allowing heirs to bypass exchange 2FA barriers when claiming inherited accounts.

Assisted 1-Click QR Deposit

Pre-filled dynamic QR codes for Coinbase, Binance, Kraken, and mobile Web3 wallets. Transfers are approved via native FaceID/2FA on the exchange app with zero passwords or API keys typed into Cadence.

Cadence replaces fragile on-chain dead man's switches with a two-phase fail-safe liquidation model designed to prevent accidental triggers during emergencies:

1. Attestation & Grace

If a check-in lapses, guardians submit attestations. When 2 of 3 confirm, a 14-day grace window begins. The owner is alerted via multiple channels and can abort the release with zero gas.

2. Merkle Proof Claim

Once grace ends, beneficiaries access the Claim Portal, decrypt their allocation package, and submit their cryptographic Merkle proof on-chain to unlock their allotment.

3. Streaming Release

The 10% emergency buffer is released immediately. The remaining 90% streams second-by-second into an autonomous smart contract, shielding heirs from drainers and market dumps.

4. Guardian Circuit Breaker

If an heir's key is compromised, guardians can call pauseStream() or redirect unvested stream outflows to a pre-registered backup cold storage address.

5. Decrypt Legacy Box & Live 2FA

Heirs sign a one-click authorization to decrypt their Off-Chain Legacy Box strictly in volatile RAM. A synchronized Google Authenticator card renders live 6-digit 2FA codes for seamless exchange login without needing the deceased benefactor's phone.

Cadence contracts are verified and deterministic across testnet deployments. Inspect the verified source code directly on the respective block explorer:

Primary USDG Vault

0x07f9...525d

Paxos USDG Token

0x75ef...66fb

Consensus Engine

0xe340...8ae1

Guardian Registry

0xe09c...ade7

Vault Factory

0xac0f...8622

Beneficiary Factory

0xebbC...EbAf

Stylus WASM Verifier

0x583e...671E

Read endpoints return JSON and require no API key. Sensitive actions require cryptographic EIP-712 signatures:

GET /api/vaults

Active vault configuration, heartbeat countdown, balance commitments, and active stream status for an owner.

GET /api/monitored-vaults

Sentinel monitoring feed of vaults nearing heartbeat expiration or currently in grace period. Guardian contact info is cryptographically masked.

POST /api/bind

Binds a guardian Ethereum address to an email notification endpoint using an off-chain EIP-712 signature with lockout protection.

GET /api/proof?vault=

Generates the verified cryptographic Merkle proof for an authenticated heir to claim on-chain without exposing siblings.

POST /api/dismiss

Relays a gasless EIP-712 dismissal signature signed by the vault owner to immediately abort false-alarm grace periods.

POST /api/secret-box/upload

Accepts an EIP-191 authenticated encrypted ciphertext blob (max 10MB) and pins it to decentralized IPFS storage.

GET /api/secret-box/[cid]

Streams raw encrypted ciphertext with strict path traversal sanitization and nosniff headers for client-side RAM decryption.