Multichain Architecture

General

The vault is designed to operate across all integrated blockchain networks simultaneously and synchronously. It is a dynamic and extensible system which can accommodate new deployments to an already live and functional system.

Global State Syncronization

Contracts stay in sync across all integrated networks at all times using offchain keeper bots. Same pricing for shUSD is guaranteed no matter which network a user deposits into or withdraws from. This backend framework also ensures that no value can be extracted by malevolent parties seeking to game network lags between the system's distributed parts.

Safety Frameworks

There is a multi-component safety mechanism in place to keep all vaults coordinated. Key to this mechanism are the pause functions and the global sync checks.

The pause gets initiated across all networks simultaneously each time the cycle is advanced forward and during rebalancing. This maintains tamper resistance from cross-chain price arbitrage and/or other timing attacks.

The global sync check verifies that per chain contract states are the same before permitting the vault prices to be updated during the cycle advancement, and then double checks again before getting unpaused. This process causes a short period of downtime of roughly 2-5 minutes every time the cycle gets advanced forward or rebalancing operations are run.

In order for any of the keeper's returned onchain data to be considered true, 4 out of the 5 RPCs calls must present the same results. Each of these calls is made using an entirely separate provider's endpoint. If consensus is not achieved the keeper/operator will rerun the check until sufficient results are achieved.

Fallback Emergency Unpause

In the extremely rare case that the pause function stays paused for an extended period of time there is an emergency unpause mechanism in place. This allows any account to trigger the unpause so long as 24 hours have elapsed since the initial pause was implemented.

Network Hierarchy

The primary vault contracts are deployed on Ethereum. All other networks are deemed secondary vaults. When the shUSD price is set on the primary vault's network this is propagated onto all secondary networks instantly (again using the same multi RPC consensus described above.) All yield accrued by the global strategy will be automatically accounted for by the primary network and sherpaUSD will be minted at 1:1 ratio to exactly represent the newly accrued yield. Regardless of whether primary or secondary, all integrated networks are of equal importance as they all play a critical role in setting the global price of shUSD within the multichain vault system's state.

┌──────────────────────────────────────────────────────────────────────┐
│                        SherpaVault System                            │
│                     Multi-Chain Architecture                         │
├──────────────────────────────────────────────────────────────────────┤
│                                                                      │
│         ┌──────────────┐              ┌──────────────┐               │
│         │   Ethereum   │              │     Base     │               │
│         │  (Primary)   │              │  (Secondary) │               │
│         ├──────────────┤              ├──────────────┤               │
│         │ SherpaVault  │              │ SherpaVault  │               │
│         │   (shUSD)    │              │   (shUSD)    │               │
│         ├──────────────┤              ├──────────────┤               │
│         │  SherpaUSD   │              │  SherpaUSD   │               │
│         ├──────────────┤              ├──────────────┤               │
│         │    USDC      │              │    USDC      │               │
│         └──────┬───────┘              └───────┬──────┘               │
│                │                              │                      │
│                │       CCIP Network           │                      │
│                │    (Any chain ↔ Any chain)   │                      │
│                │                              │                      │
│                └──────────┬───────────────┬───┘                      │
│                           │               │                          │
│                     ┌─────▼──────┐        │   ┌ ─ ─ ─ ─ ─ ─ ─ ─ ─    │
│                     │   Monad    │        │      Future Chains   │   │
│                     │(Secondary) │        │   │ (Arbitrum, Bera      │
│                     ├────────────┤        └───►  HyperEVM, etc)  │   │
│                     │SherpaVault │            │                      │
│                     │  (shUSD)   │             ─ ─ ─ ─ ─ ─ ─ ─ ─ ┘   │
│                     ├────────────┤                                   │
│                     │ SherpaUSD  │   Add new chains via:             │
│                     ├────────────┤   docs/ADD_NEW_CHAIN_PIPELINE.md  │
│                     │   USDC     │                                   │
│                     └────────────┘                                   │
│                                                                      │
│  Global State Synchronization (example):                             │
│  • Round 15, Epoch 15 on ALL chains (present and future)             │
│  • Price: 1.05767 USDC/shUSD (same everywhere)                       │
│  • Total: 600k Ethereum, 400k Base, 250k Aritrum = 1.25M USDC global │
│      total staked across all chains                                  │
│  • CCIP enables direct bridging between any connected chain pair     │
│                                                                      │
└──────────────────────────────────────────────────────────────────────┘