# Smart Interception - Implementation Summary

**Date**: 2026-01-06  
**Status**: ✅ **IMPLEMENTED**

---

## What Was Changed

### 1. Web3SignerClient - Added `hasKey()` Method

**File**: `src/clients/web3signer-client.ts`

```typescript
async hasKey(address: string): Promise<boolean> {
  // Queries Web3Signer API for all loaded keys
  // Checks if the address is in the list
  // Returns false if check fails (allows pass-through)
}
```

### 2. RPC Handler - Smart Interception Logic

**File**: `src/handlers/rpc-handler.ts`

**Before**: All `eth_sendTransaction` calls were intercepted

**After**: 
- Check if address has key in Web3Signer
- **No key** → Pass through to Besu (user wallet)
- **Has key** → Intercept and sign via Web3Signer (service wallet)

### 3. Main Entry Point - Pass Web3Signer Client

**File**: `src/main.ts`

- Pass `web3SignerClient` to `RpcHandler` constructor
- Enables smart interception functionality

---

## How It Works Now

### Flow for User Wallets (MetaMask)

```
eth_sendTransaction from 0x71e81eaec98e507f68bbcf5e2005f179db851603
    ↓
Translator checks: Has key in Web3Signer? NO
    ↓
Pass through to Besu ✅
    ↓
Besu handles (or returns error if unsigned)
```

### Flow for Service Wallets

```
eth_sendTransaction from 0xServiceWallet (has key in Web3Signer)
    ↓
Translator checks: Has key in Web3Signer? YES
    ↓
Intercept and sign via Web3Signer ✅
    ↓
Convert to eth_sendRawTransaction
    ↓
Submit to Besu ✅
```

---

## Benefits

1. ✅ **Automatic**: No manual configuration needed
2. ✅ **MetaMask Compatible**: User wallets work automatically
3. ✅ **Service Wallet Support**: Still signs via Web3Signer
4. ✅ **Backward Compatible**: Existing allowlist still works
5. ✅ **Fail-Safe**: If check fails, defaults to pass-through

---

## Deployment

### Quick Deploy

```bash
cd /home/intlc/projects/proxmox/rpc-translator-138
./scripts/deploy-smart-interception.sh
```

### Manual Deploy

```bash
# 1. Build
pnpm run build

# 2. Deploy to all VMIDs
./scripts/deploy-all-vmids.sh

# 3. Verify
./scripts/check-all-status.sh
```

---

## Testing

### Test User Wallet (Should Pass Through)

```bash
curl -X POST http://192.168.11.240:9545 \
  -H 'Content-Type: application/json' \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_sendTransaction",
    "params": [{
      "from": "0x71e81eaec98e507f68bbcf5e2005f179db851603",
      "to": "0x0000000000000000000000000000000000000000",
      "value": "0x0"
    }],
    "id": 1
  }'
```

**Expected**: Passes through to Besu (may get error from Besu, but that's expected)

### Test Service Wallet (Should Intercept)

```bash
# Get service wallet address
ADDRESS=$(curl -s http://192.168.11.111:9000/api/v1/eth1/publicKeys | jq -r '.[0]')

# Send transaction
curl -X POST http://192.168.11.240:9545 \
  -H 'Content-Type: application/json' \
  -d "{
    \"jsonrpc\": \"2.0\",
    \"method\": \"eth_sendTransaction\",
    \"params\": [{
      \"from\": \"$ADDRESS\",
      \"to\": \"0x0000000000000000000000000000000000000000\",
      \"value\": \"0x0\"
    }],
    \"id\": 1
  }"
```

**Expected**: Intercepted, signed via Web3Signer, submitted to Besu

### Check Logs

```bash
# Look for smart interception messages
ssh -i ~/.ssh/proxmox_translator root@192.168.11.240 \
  "journalctl -u rpc-translator-138.service -n 50 --no-pager | grep -i 'has.*key\|pass.*through\|intercepting'"
```

---

## Configuration

### Allowlist (Optional Now)

**With smart interception, allowlist is optional for user wallets:**

- **Empty allowlist**: All addresses can send (not recommended for production)
- **Populated allowlist**: Only listed addresses can send (additional security layer)

**Recommended:**
- Keep allowlist with only service wallet addresses
- User wallets don't need to be in allowlist

---

## Integration with Thirdweb

### MetaMask Users

**Already works!** No changes needed:
1. User connects MetaMask
2. Thirdweb SDK detects wallet
3. User signs transaction locally
4. Thirdweb sends `eth_sendRawTransaction` (passes through ✅)

**OR** if Thirdweb uses `eth_sendTransaction`:
1. Translator checks: No key in Web3Signer
2. Translator passes through to Besu ✅

### Service Wallets

**Works with smart interception:**
1. Service wallet has key in Web3Signer
2. Thirdweb calls `eth_sendTransaction` (unsigned)
3. Translator checks: Has key in Web3Signer ✅
4. Translator intercepts and signs via Web3Signer ✅
5. Transaction submitted to Besu ✅

---

## Summary

✅ **Smart interception implemented**
✅ **User wallets (MetaMask) automatically pass through**
✅ **Service wallets still get signed via Web3Signer**
✅ **No configuration changes needed**
✅ **Backward compatible**

**Next Step**: Deploy using `./scripts/deploy-smart-interception.sh`
