# Chain 138 – Wallet & SDK Config Validation

**Last Updated:** 2026-01-31  
**Document Version:** 1.0  
**Status:** Active Documentation

---

**Purpose**: Validated configs for MetaMask, ethers.js, and Ledger (Chain 138 – Defi Oracle Meta Mainnet).  
**RPC**: `https://rpc-http-pub.d-bis.org`, `https://rpc.d-bis.org`, `https://rpc2.d-bis.org`, `https://rpc.defi-oracle.io`  
**WS**: `wss://rpc-ws-pub.d-bis.org`, `wss://rpc.d-bis.org`, `wss://ws.rpc.d-bis.org`, `wss://ws.rpc2.d-bis.org`, `wss://wss.defi-oracle.io`  
**Chain ID**: 138 (`0x8a`)

---

## 1. MetaMask (custom network)

Use **Settings → Networks → Add network** (or “Add a network manually”) with:

| Field | Value |
|-------|--------|
| **Network name** | Defi Oracle Meta Mainnet |
| **RPC URL** | `https://rpc-http-pub.d-bis.org`, `https://rpc.d-bis.org`, `https://rpc2.d-bis.org`, or `https://rpc.defi-oracle.io` |
| **Chain ID** | `138` |
| **Currency symbol** | ETH |
| **Block explorer** | `https://explorer.d-bis.org` |

**JSON** (for programmatic add or import): see `docs/04-configuration/metamask/METAMASK_NETWORK_CONFIG.json`.

Validated: chainId `0x8a`, RPC URLs return `eth_chainId` → `0x8a`.

---

## 2. ethers.js (v5 / v6)

```javascript
// Chain 138 – Defi Oracle Meta Mainnet
const chain138 = {
  chainId: 138,
  name: "Defi Oracle Meta Mainnet",
  nativeCurrency: { name: "Ether", symbol: "ETH", decimals: 18 },
  rpcUrls: {
    default: { http: ["https://rpc-http-pub.d-bis.org", "https://rpc.d-bis.org", "https://rpc2.d-bis.org", "https://rpc.defi-oracle.io"] },
    webSocket: ["wss://rpc-ws-pub.d-bis.org", "wss://rpc.d-bis.org", "wss://ws.rpc.d-bis.org", "wss://ws.rpc2.d-bis.org", "wss://wss.defi-oracle.io"]
  },
  blockExplorers: {
    default: { name: "Blockscout", url: "https://explorer.d-bis.org" }
  }
};

// ethers v6
import { JsonRpcProvider } from "ethers";
const provider = new JsonRpcProvider("https://rpc-http-pub.d-bis.org");
const chainId = await provider.getNetwork().then(n => Number(n.chainId)); // 138

// ethers v6 WebSocket
import { WebSocketProvider } from "ethers";
const wsProvider = new WebSocketProvider("wss://rpc-ws-pub.d-bis.org");
```

Validated: HTTP RPC returns chainId 138; WS endpoints route to same backend (VMID 2201).

---

## 3. Ledger (Chain 138)

Chain 138 is a custom chain. In Ledger Live / Ledger-compatible apps:

- **Network**: Add custom Ethereum-compatible network.
- **RPC**: `https://rpc-http-pub.d-bis.org`, `https://rpc.d-bis.org`, `https://rpc2.d-bis.org`, or `https://rpc.defi-oracle.io`
- **Chain ID**: `138`
- **Explorer**: `https://explorer.d-bis.org`

Ledger does not pre-list Chain 138; use “Add custom network” (or equivalent) with the values above.  
**SLIP-44**: Chain 138 uses `slip44: 60` (ETH derivation path) in chain list; Ledger uses standard ETH path for EVM chains.

Validated: No collision with mainnet (1) or common testnets; chain list entry in `pr-workspace/chains/_data/chains/eip155-138.json` is correct for submission to chainlist.org / Ledger discovery if/when supported.

---

## 4. Quick verification

```bash
# HTTP RPC
curl -s -X POST https://rpc-http-pub.d-bis.org -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"eth_chainId","params":[],"id":1}'
# Expected: {"jsonrpc":"2.0","id":1,"result":"0x8a"}

# From LAN (if Split DNS or --resolve used)
curl -sk --resolve rpc-http-pub.d-bis.org:443:192.168.11.167 \
  https://rpc-http-pub.d-bis.org \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"eth_chainId","params":[],"id":1}'
```

---

## 5. References

- **RPC verification**: `docs/04-configuration/RPC_CHAIN138_VERIFICATION.md`
- **MetaMask network JSON**: `docs/04-configuration/metamask/METAMASK_NETWORK_CONFIG.json`
- **Chain list (chainlist.org)**: `pr-workspace/chains/_data/chains/eip155-138.json`
- **Token list (chain 138)**: `token-lists/chainlists/chain-138.json`
- **Testnet (2138) wallet doc**: `docs/04-configuration/CHAIN2138_WALLET_CONFIG_VALIDATION.md`