Contract Overview

The SLASettle smart contract layer is implemented in Rust using the Soroban SDK (soroban-sdk 28.0.0) targeting Stellar Protocol 28. It is organized into two distinct, loosely coupled contracts hosted in the SLASettleHQ/slasettle-vault repository.

Contract Architecture & Coupling

+-------------------------------------------------------+
|                   watcher_registry                    |
|  - Manages watcher set & counts per-round votes       |
|  - Emits: CheckSubmitted, WatcherRegistered/Removed   |
+-------------------------------------------------------+
                           ^
                           | Cross-contract read:
                           | get_round_tally(sla_id, round_id)
                           |
+-------------------------------------------------------+
|                       sla_vault                       |
|  - Holds provider collateral in escrow                |
|  - Interprets quorum: votes_down >= quorum_threshold  |
|  - Executes penalty transfers to beneficiaries        |
|  - Emits: SlaCreated, BondToppedUp, SettlementPaid,   |
|           SlaCancelled, BondWithdrawn                 |
+-------------------------------------------------------+

Clean Separation of Concerns

1. watcher_registry:
   • Acts strictly as an attestation registry and round tally aggregator.
   • Has zero dependencies on sla_vault or any financial/token contracts.
   • Does not enforce quorum thresholds or make settlement decisions.
2. sla_vault:
   • Manages agreement lifecycle, collateral balances, and payouts.
   • References watcher_registry via a stored contract address initialized at deployment.
   • Performs cross-contract calls using the compiled client (watcher_registry_contract::Client) to inspect round vote tallies.
   • Contains all economic and quorum enforcement logic.

Deployed Contract Addresses (Stellar Testnet)

Contract Name	Address	Functionality
sla_vault	CDBFPYHJNYSIFXSMXF3BBDWPKHRS7SJFFEKMQ5WJXYTBMD4LFAG2CHLN	Collateral escrow, agreement configuration, and penalty settlement.
watcher_registry	CDRNXUPCZTVZXKPWNBQZAYI6HYFNBDHRO2KNNJSMDVTEHFOM7LCMOYMF	Node registration, check attestation, and vote tallying.

• Network: Stellar Testnet
• Network Passphrase: Test SDF Network ; September 2015
• RPC URL: https://soroban-testnet.stellar.org

Building from Source

To compile the smart contracts from the slasettle-vault repository:

git clone https://github.com/SLASettleHQ/slasettle-vault.git
cd slasettle-vault

# Build both release WASM targets
stellar contract build

# WASM artifacts output:
# target/wasm32-unknown-unknown/release/watcher_registry.wasm
# target/wasm32-unknown-unknown/release/sla_vault.wasm

Deterministic compilation with stellar contract build produces bytecode that matches the deployed Testnet contracts byte-for-byte.