chronopay-contracts

Soroban smart contracts for ChronoPay — time tokenization and scheduling on the Stellar network.

What's in this repo

• Time token contract (contracts/chronopay): Soroban contract for:
  • create_time_slot(professional, start_time, end_time)
  • mint_time_token(slot_id, owner)
  • buy_time_token(token_id, buyer, seller)
  • redeem_time_token(token_id, redeemer)

Access control and failure modes

The contract currently enforces owner-based authorization for token lifecycle operations in contracts/chronopay/src.

• mint_time_token requires owner authorization and rejects unknown slots.
• buy_time_token requires both buyer and seller authorization and rejects transfers from non-owners.
• redeem_time_token requires redeemer authorization and allows redemption only by the current owner.
• Redeemed tokens cannot be redeemed again.
• Missing tokens fail explicitly instead of mutating contract state.

Acceptance criteria for the redeem access-control flow:

• Only the current token owner can redeem a token.
• Ownership transfer changes who is allowed to redeem.
• Repeated redemption attempts fail.
• Invalid slot or token identifiers fail without changing ownership or status.
• Automated tests cover success, authorization failure, invalid input, and repeat-action failure paths.

Defensive Arithmetic Notes

contracts/chronopay/src now applies explicit arithmetic validation in create_time_slot so timestamp and sequence handling do not rely on Rust's debug-only overflow behavior.

• end_time must be strictly greater than start_time
• slot id allocation fails cleanly when the internal sequence reaches u32::MAX
• invalid arithmetic paths return typed contract errors that are covered by tests

Acceptance criteria for this change:

• slot creation succeeds for valid increasing timestamps
• zero-length and inverted time ranges are rejected
• slot sequence overflow is rejected without mutating storage
• the existing mint / buy / redeem stubs continue to behave as before

Prerequisites

• Rust (stable)
• rustfmt: rustup component add rustfmt
• For deployment: Stellar CLI (optional)

Setup

# Clone the repo (or use your fork)
git clone <repo-url>
cd chronopay-contracts

# Build
cargo build

# Run tests
cargo test

# Check formatting
cargo fmt --all -- --check

Project layout

chronopay-contracts/
├── Cargo.toml              # Workspace definition
├── contracts/
│   └── chronopay/
│       ├── Cargo.toml
│       └── src/
│           ├── lib.rs      # Contract logic
│           └── test.rs     # Unit tests
└── .github/workflows/
    └── ci.yml              # CI: fmt, build, test

Contributing

1. Fork the repo and create a branch from main.
2. Make changes; keep formatting clean: cargo fmt.
3. Ensure tests pass: cargo test.
4. Open a pull request. CI must pass (fmt check, build, tests).

CI/CD

On every push and pull request to main, GitHub Actions runs:

• Format: cargo fmt --all -- --check
• Build: cargo build
• Tests: cargo test

License

MIT