# Kaleido Tether and Mirror Pattern Implementation

**Date**: 2025-12-11
**Reference**: Kaleido's cross-chain architecture patterns

---

## 📚 Understanding Kaleido's Patterns

### **Tether Contract** (State Anchoring)

In Kaleido's architecture, a **Tether** contract is deployed on a public Ethereum network (e.g., Mainnet) that:
- Stores signed state proofs from a private blockchain network
- Creates an immutable, verifiable record of the private chain's state
- Anchors the private chain's state to the public network at specific intervals
- Provides security and transparency by making state proofs publicly verifiable
- Prevents collusion by requiring collective signatures from all nodes

**Purpose**: State anchoring and integrity verification across chains

---

### **Mirror Contract** (Address Registry)

In Kaleido's architecture, a **Mirror** contract:
- Maintains a registry of mirrored token/contract addresses across chains
- Maps source chain addresses to destination chain addresses
- Provides replay protection for cross-chain operations
- Enables address resolution for cross-chain interactions

**Purpose**: Address mapping and cross-chain contract resolution

---

## 🔍 Implementation in This Codebase

### 1. MirrorManager Contract ✅

**File**: `contracts/mirror/MirrorManager.sol`
**Status**: ✅ Available, ❌ Not deployed to Mainnet

**Functionality**:
- Registry of mirrored token/contract addresses across chains
- Mapping: `(sourceChain, sourceAddress) => (destChain => destAddress)`
- Replay protection via `processed` mapping
- Pausability for emergency stops
- Admin-controlled configuration

**Kaleido Pattern**: ✅ **Implements Mirror pattern**

**Deployment**:
```bash
forge script script/DeployMirrorManager.s.sol \
  --rpc-url $ETH_MAINNET_RPC_URL \
  --private-key $PRIVATE_KEY \
  --broadcast \
  --verify
```

**Required Environment Variables**:
- `MIRROR_ADMIN` - Admin address (multisig recommended)

---

### 2. TwoWayTokenBridge (Tether-like Pattern) ✅

**Files**:
- `contracts/bridge/TwoWayTokenBridgeL1.sol` (Mainnet/L1 side)
- `contracts/bridge/TwoWayTokenBridgeL2.sol` (Chain-138/L2 side)

**Status**: ✅ Available, ❌ Not deployed to Mainnet

**Functionality**:
- **L1 Side**: Locks canonical tokens and sends CCIP messages to mint on L2
- **L2 Side**: Mints mirrored tokens on inbound, burns on outbound
- State synchronization via CCIP messages
- Replay protection
- Destination chain configuration

**Kaleido Pattern**: ✅ **Implements Tether-like pattern** (state synchronization)

**Deployment**:
```bash
forge script script/DeployTwoWayBridge.s.sol \
  --rpc-url $ETH_MAINNET_RPC_URL \
  --private-key $PRIVATE_KEY \
  --broadcast \
  --verify
```

**Required Environment Variables**:
- `CCIP_ROUTER` - CCIP router address (set)
- `CCIP_FEE_TOKEN` - LINK token address (set)
- `BRIDGE_L1_TOKEN` - Canonical token on Mainnet (NOT SET)
- `BRIDGE_L2_TOKEN` - Mintable token on Chain-138 (NOT SET)

---

## 🔄 Relationship Between Contracts

### MirrorManager + TwoWayTokenBridge

1. **MirrorManager** maintains the address registry:
   - Maps Mainnet token addresses to Chain-138 addresses
   - Used by other contracts to resolve cross-chain addresses

2. **TwoWayTokenBridge** handles token transfers:
   - Uses MirrorManager to resolve destination addresses
   - Locks tokens on L1, mints on L2 (or vice versa)
   - Maintains state synchronization via CCIP

### Typical Flow:

```
User on Mainnet
  ↓
TwoWayTokenBridgeL1.lockAndSend()
  ↓
CCIP Message → Chain-138
  ↓
TwoWayTokenBridgeL2.ccipReceive()
  ↓
MirrorManager.getMirror() → Resolve address
  ↓
Mint mirrored tokens on Chain-138
```

---

## 📋 Deployment Status

### ✅ Available Contracts

| Contract | Pattern | Status | Deployment Script |
|----------|---------|--------|------------------|
| **MirrorManager** | Mirror | ❌ Not Deployed | `script/DeployMirrorManager.s.sol` |
| **TwoWayTokenBridgeL1** | Tether-like | ❌ Not Deployed | `script/DeployTwoWayBridge.s.sol` |
| **TwoWayTokenBridgeL2** | Tether-like | ❌ Not Deployed | `script/DeployTwoWayBridge.s.sol` |

### ⚠️ Missing Configuration

**MirrorManager**:
- `MIRROR_ADMIN` - Not set in `.env`

**TwoWayTokenBridge**:
- `BRIDGE_L1_TOKEN` - Not set in `.env`
- `BRIDGE_L2_TOKEN` - Not set in `.env`

---

## 🚀 Deployment Plan

### Step 1: Deploy MirrorManager

```bash
# Set admin address (multisig recommended)
export MIRROR_ADMIN=0x...

# Deploy
forge script script/DeployMirrorManager.s.sol \
  --rpc-url $ETH_MAINNET_RPC_URL \
  --private-key $PRIVATE_KEY \
  --broadcast \
  --verify

# Update .env
echo "MIRRORMANAGER_MAINNET=<deployed_address>" >> .env
```

### Step 2: Deploy TwoWayTokenBridge

```bash
# Set token addresses
export BRIDGE_L1_TOKEN=0x...  # Canonical token on Mainnet
export BRIDGE_L2_TOKEN=0x...  # Mintable token on Chain-138

# Deploy (deploys both L1 and L2)
forge script script/DeployTwoWayBridge.s.sol \
  --rpc-url $ETH_MAINNET_RPC_URL \
  --private-key $PRIVATE_KEY \
  --broadcast \
  --verify

# Update .env
echo "TWOWAY_BRIDGE_L1_MAINNET=<l1_address>" >> .env
echo "TWOWAY_BRIDGE_L2_CHAIN138=<l2_address>" >> .env
```

### Step 3: Configure MirrorManager

```bash
# Register bridge addresses in MirrorManager
cast send $MIRRORMANAGER_MAINNET \
  "setMirror(uint64,address,uint64,address)" \
  1 \  # Mainnet chain selector
  $TWOWAY_BRIDGE_L1_MAINNET \
  138 \  # Chain-138 selector
  $TWOWAY_BRIDGE_L2_CHAIN138 \
  --rpc-url $ETH_MAINNET_RPC_URL \
  --private-key $PRIVATE_KEY
```

### Step 4: Configure TwoWayTokenBridge

```bash
# Configure L1 bridge to point to L2
cast send $TWOWAY_BRIDGE_L1_MAINNET \
  "addDestination(uint64,address)" \
  138 \  # Chain-138 selector
  $TWOWAY_BRIDGE_L2_CHAIN138 \
  --rpc-url $ETH_MAINNET_RPC_URL \
  --private-key $PRIVATE_KEY

# Configure L2 bridge to point to L1
cast send $TWOWAY_BRIDGE_L2_CHAIN138 \
  "addDestination(uint64,address)" \
  1 \  # Mainnet selector
  $TWOWAY_BRIDGE_L1_MAINNET \
  --rpc-url $RPC_URL_138 \
  --private-key $PRIVATE_KEY
```

---

## 🔗 Integration with Existing Contracts

### CCIPWETH9Bridge / CCIPWETH10Bridge

The existing CCIP bridges can use MirrorManager to:
- Resolve destination addresses for cross-chain transfers
- Verify address mappings before processing transfers
- Maintain consistency across chains

### Example Integration:

```solidity
// In CCIPWETH9Bridge
MirrorManager mirror = MirrorManager(mirrorManagerAddress);
address destBridge = mirror.getMirror(
    block.chainid,
    address(this),
    destChainSelector
);
```

---

## 📊 Comparison with Kaleido

| Feature | Kaleido Pattern | This Implementation |
|---------|----------------|---------------------|
| **State Anchoring** | Tether Contract | TwoWayTokenBridge |
| **Address Registry** | Mirror Contract | MirrorManager |
| **Cross-Chain Messaging** | Custom | CCIP (Chainlink) |
| **Replay Protection** | ✅ | ✅ |
| **Pausability** | ✅ | ✅ |
| **Admin Control** | ✅ | ✅ |

---

## ⚠️ Important Notes

1. **MirrorManager** should be deployed before TwoWayTokenBridge for proper address resolution
2. **TwoWayTokenBridge** requires mintable tokens on L2 (Chain-138)
3. Both contracts should use multisig for admin addresses
4. Configure MirrorManager mappings after deployment
5. Test with small amounts before production use

---

## 📚 References

- [Kaleido Tether Documentation](https://docs.kaleido.io/kaleido-services/tether/)
- [Kaleido Mirror Pattern](https://docs.kaleido.io/)
- [CCIP Documentation](https://docs.chain.link/ccip)

---

**Last Updated**: 2025-12-11
**Status**: Documentation complete, deployment pending