TTL-Legacy — Micro-Endowment Check-In Vault on Stellar

A decentralized "Dead Man's Switch" built on Stellar/Soroban smart contracts.

TTL-Legacy is a time-capsule vault where funds (XLM or tokenized assets) are released to a beneficiary only if the owner fails to "check in" via a Passkey-powered interface. It leverages Soroban's State Archival and TTL (Time to Live) features to automate asset inheritance — no seed phrase complexity required.

🎯 What is TTL-Legacy?

TTL-Legacy turns Stellar's native state archival mechanics into a programmable inheritance trigger. Vault owners:

• Deposit funds into a personal vault contract
• Periodically "check in" to extend the contract's TTL and prove liveness
• Designate a beneficiary address for automatic release
• Authenticate exclusively via Passkeys (WebAuthn) — no seed phrases

If the owner stops checking in, the contract's TTL expires and the vault automatically releases funds to the beneficiary.

This Soroban implementation makes TTL-Legacy:

✅ Trustless (no executor, lawyer, or coordinator needed)
✅ Transparent (all vault state and transfers are on-chain)
✅ Secure (Passkey/WebAuthn authentication, no exposed seed phrases)
✅ Automated (TTL expiry triggers transfer without manual intervention)

🚀 Features

• Create a Vault: Set a beneficiary address and check-in interval
• Check-In: Extend the contract TTL to reset the countdown
• Automatic Release: Funds transfer to beneficiary when TTL lapses
• Passkey Auth: WebAuthn-based authentication for all owner actions
• Reminder System: Backend sends encrypted email/SMS check-in reminders
• Legacy Dashboard: Minimalist frontend to manage vault state and history
• Native XLM Support: Built-in support for Stellar Lumens
• Token Ready: Architecture supports custom Stellar tokens (roadmap item)

🛠️ Quick Start

Prerequisites

• Rust (1.70+)
• Soroban CLI
• Stellar CLI

Build

./scripts/build.sh

Test

./scripts/test.sh

Setup Environment

Copy the example environment file:

cp .env.example .env

Configure your environment variables in .env:

# Network configuration
STELLAR_NETWORK=testnet
STELLAR_RPC_URL=https://soroban-testnet.stellar.org

# Contract addresses (after deployment)
CONTRACT_TTL_VAULT=<your-contract-id>

# Frontend configuration
VITE_STELLAR_NETWORK=testnet
VITE_STELLAR_RPC_URL=https://soroban-testnet.stellar.org

# Backend (reminder service)
REMINDER_EMAIL_API_KEY=<your-key>
REMINDER_SMS_API_KEY=<your-key>

Network configurations are defined in environments.toml:

• testnet — Stellar testnet
• mainnet — Stellar mainnet
• futurenet — Stellar futurenet
• standalone — Local development

Deploy to Testnet

# Configure your testnet identity first
stellar keys generate deployer --network testnet

# Deploy
./scripts/deploy_testnet.sh

📖 Documentation

• Architecture Overview
• TTL & State Archival Logic
• Passkey Integration
• Threat Model & Security
• Security Policy & Vulnerability Disclosure
• Roadmap

🎓 Smart Contract API

Vault Management

create_vault(beneficiary: Address, check_in_interval: u64) -> u64
get_vault(vault_id: u64) -> Vault
get_ttl_remaining(vault_id: u64) -> Option<u64>

Owner Actions

check_in(vault_id: u64)
deposit(vault_id: u64, amount: i128)
withdraw(vault_id: u64, amount: i128)
update_beneficiary(vault_id: u64, new_beneficiary: Address)

Release

trigger_release(vault_id: u64)
is_expired(vault_id: u64) -> bool
get_release_status(vault_id: u64) -> ReleaseStatus

🧪 Testing

Comprehensive test suite covering:

✅ Vault creation and configuration
✅ Check-in flow and TTL extension
✅ TTL expiry and automatic release
✅ Passkey authentication validation
✅ Beneficiary payout execution
✅ Error handling and edge cases

Run tests:

cargo test

🌍 Why This Matters

The Problem: Over $140 billion in crypto assets are estimated to be permanently lost due to inaccessible wallets. Traditional inheritance mechanisms don't map to self-custodied digital assets.

Blockchain Benefits:

• No trusted executor or legal intermediary required
• Transparent vault state and release history on-chain
• Programmable rules enforced by smart contracts
• Passkey auth removes the seed phrase single point of failure

Target Users:

• Long-term crypto holders planning for asset continuity
• Individuals without access to traditional estate planning
• Families and communities building generational wealth on-chain
• Anyone who wants a secure, automated digital legacy plan

🗺️ Roadmap

• v1.0 (Current): XLM vaults, TTL-based release, Passkey auth
• v1.1: Custom token support (USDC, EURC, etc.)
• v2.0: Multi-beneficiary splits, conditional release logic
• v3.0: Mobile-friendly frontend, push notification reminders
• v4.0: Fiat on/off-ramps, legal document anchoring via Stellar

See docs/roadmap.md for details.

🤝 Contributing

We welcome contributions! Please:

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

See our Code of Conduct and Contributing Guidelines.

📄 License

This project is licensed under the MIT License — see the LICENSE file for details.

🙏 Acknowledgments

• Stellar Development Foundation for Soroban
• The WebAuthn/Passkey standards community
• Everyone building toward self-sovereign financial tools