streampay-contracts

Soroban smart contracts for StreamPay — continuous payment streaming on the Stellar network.

Overview

This repo contains the on-chain logic for creating, starting, stopping, and settling payment streams. Contracts are written in Rust using the Soroban SDK.

Contract interface

• create_stream(payer, recipient, rate_per_second, initial_balance) — Create a new stream (payer must auth).
• start_stream(stream_id) — Start an existing stream.
• stop_stream(stream_id) — Stop an active stream.
• settle_stream(stream_id) — Compute and deduct streamed amount since last settlement; returns amount.
• archive_stream(stream_id) — Remove a fully-settled, inactive stream from storage (payer must auth).
• get_stream_info(stream_id) — Read stream metadata (payer, recipient, rate, balance, timestamps, active).
• version() — Returns the contract version as a u32 (no auth required).

Storage Model

Streams are stored in Soroban persistent storage with per-stream TTL management. Each stream is an independent ledger entry that can expire independently. The contract instance storage holds only the next_id counter.

See docs/factory-pattern.md for the full design rationale and future factory pattern graduation path.

Version encoding

The on-chain version uses a packed u32 scheme: major * 1_000_000 + minor * 1_000 + patch.

Semver	u32
0.1.0	1 000
1.0.0	1 000 000
1.2.3	1 002 003

When releasing, update both Cargo.toml version and the VERSION const in src/lib.rs.

Prerequisites

• Rust (stable, with rustfmt)
• Optional: Stellar CLI for deployment

Setup for contributors

1. Clone and enter the repo

   git clone <repo-url>
   cd streampay-contracts

2. Install Rust

   curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
   rustup component add rustfmt

3. Verify setup

   cargo fmt --all -- --check
   cargo build
   cargo test

Scripts

Command	Description
cargo build	Build the contract
cargo test	Run unit tests
cargo fmt	Format code
cargo fmt --all -- --check	Check formatting (CI)

CI/CD

On every push/PR to main, GitHub Actions runs:

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

Ensure all three pass before merging.

Releases

Tagged releases follow semver. Each release includes an optimized WASM artifact and SHA-256 checksum.

See docs/RELEASE.md for the full release process, including how to verify WASM builds.

Project structure

streampay-contracts/
├── src/
│   └── lib.rs                        # Contract and tests
├── docker/
│   └── Dockerfile.build              # Deterministic WASM builder
├── .github/workflows/
│   ├── ci.yml                        # Format, build, test
│   └── release.yml                   # Tagged release workflow
├── docs/
│   └── RELEASE.md                    # Release process guide
├── cliff.toml                        # Changelog generator config
├── rust-toolchain.toml               # Pinned Rust version
├── Cargo.toml
├── CHANGELOG.md
└── README.md

License

MIT