# Token List Integration Guide

**Network**: ChainID 138 (DBIS Chain)  
**Token List**: DBIS Chain 138 Token List  
**Last Updated**: 2025-12-22

---

## Overview

This guide explains how to integrate the DBIS Chain 138 Token List into various applications, wallets, and services.

---

## Token List Endpoints

### Primary Endpoints

- **GitHub Pages**: `https://{user}.github.io/{repo}/token-lists/lists/dbis-138.tokenlist.json`
- **GitHub Raw**: `https://raw.githubusercontent.com/{user}/{repo}/main/token-lists/lists/dbis-138.tokenlist.json`
- **DBIS Domain** (if configured): `https://tokens.d-bis.org/lists/dbis-138.tokenlist.json`

### Verification

- **Signature**: `{token-list-url}.sig`
- **Checksums**: See GitHub Releases for `SHA256SUMS`
- **Public Key**: `token-lists/minisign.pub`

---

## MetaMask Integration

### Method 1: Manual Addition

1. Open MetaMask
2. Go to **Settings** → **Security & Privacy** → **Token Lists**
3. Click **"Add custom token list"**
4. Enter token list URL:
   ```
   https://raw.githubusercontent.com/{user}/{repo}/main/token-lists/lists/dbis-138.tokenlist.json
   ```
5. Click **Add**

### Method 2: Programmatic Addition

```javascript
// Add network first (if not already added)
await window.ethereum.request({
  method: 'wallet_addEthereumChain',
  params: [{
    chainId: '0x8a', // 138 in hex
    chainName: 'SMOM-DBIS-138',
    rpcUrls: ['https://rpc-core.d-bis.org'],
    nativeCurrency: {
      name: 'Ether',
      symbol: 'ETH',
      decimals: 18
    },
    blockExplorerUrls: ['https://explorer.d-bis.org']
  }]
});

// Token list is added via MetaMask UI (Settings → Token Lists)
// MetaMask doesn't provide API for programmatic token list addition
```

### Verifying Token List in MetaMask

1. Ensure you're connected to ChainID 138
2. Go to **Assets** tab
3. Click **"Import tokens"**
4. Tokens from the list should appear automatically

---

## Ledger Integration

Ledger Live doesn't directly support token lists. Use MetaMask with Ledger:

1. **Connect Ledger to MetaMask**
   - Connect Ledger device
   - Enable "Ethereum" app on Ledger
   - In MetaMask, select "Connect Hardware Wallet" → "Ledger"

2. **Add DBIS Network**
   - Follow MetaMask network addition steps above
   - Network will use Ledger for signing

3. **Add Token List**
   - Follow MetaMask token list addition steps above
   - Tokens will be available when using Ledger with MetaMask

---

## dApp Integration

### Using Web3.js

```javascript
const Web3 = require('web3');
const web3 = new Web3('https://rpc-core.d-bis.org');

// Fetch token list
async function getTokenList() {
  const response = await fetch('https://raw.githubusercontent.com/{user}/{repo}/main/token-lists/lists/dbis-138.tokenlist.json');
  const tokenList = await response.json();
  return tokenList.tokens;
}

// Use token metadata
const tokens = await getTokenList();
const wethToken = tokens.find(t => t.symbol === 'WETH');
console.log(`WETH address: ${wethToken.address}`);
console.log(`WETH decimals: ${wethToken.decimals}`);
```

### Using Ethers.js

```javascript
const { ethers } = require('ethers');
const provider = new ethers.JsonRpcProvider('https://rpc-core.d-bis.org');

// Fetch token list
async function getTokenList() {
  const response = await fetch('https://raw.githubusercontent.com/{user}/{repo}/main/token-lists/lists/dbis-138.tokenlist.json');
  const tokenList = await response.json();
  return tokenList.tokens;
}

// Create contract instance using token metadata
const tokens = await getTokenList();
const wethToken = tokens.find(t => t.symbol === 'WETH');

const erc20ABI = [
  'function balanceOf(address) view returns (uint256)',
  'function decimals() view returns (uint8)'
];

const contract = new ethers.Contract(wethToken.address, erc20ABI, provider);
const balance = await contract.balanceOf(userAddress);
const decimals = await contract.decimals();
console.log(`Balance: ${ethers.formatUnits(balance, decimals)} WETH`);
```

---

## Explorer/Indexer Integration

### Blockscout Integration

1. **Configure Token List URL**
   - Add token list URL to Blockscout configuration
   - Blockscout will fetch token metadata automatically

2. **Manual Token Addition**
   - Use Blockscout admin interface
   - Add tokens from the list manually

### Custom Indexer

```javascript
// Fetch and cache token list
async function fetchTokenList() {
  const response = await fetch('https://raw.githubusercontent.com/{user}/{repo}/main/token-lists/lists/dbis-138.tokenlist.json');
  const tokenList = await response.json();
  
  // Create lookup map
  const tokenMap = new Map();
  tokenList.tokens.forEach(token => {
    tokenMap.set(token.address.toLowerCase(), token);
  });
  
  return tokenMap;
}

// Use in indexing
const tokenMap = await fetchTokenList();
const token = tokenMap.get(contractAddress.toLowerCase());
if (token) {
  console.log(`Token: ${token.symbol} (${token.name})`);
  console.log(`Decimals: ${token.decimals}`);
  console.log(`Logo: ${token.logoURI}`);
}
```

---

## Signature Verification

Verify token list integrity using minisign:

```bash
# Install minisign (if not installed)
# macOS: brew install minisign
# Ubuntu: apt-get install minisign

# Download files
curl -O https://raw.githubusercontent.com/{user}/{repo}/main/token-lists/lists/dbis-138.tokenlist.json
curl -O https://raw.githubusercontent.com/{user}/{repo}/main/token-lists/lists/dbis-138.tokenlist.json.sig
curl -O https://raw.githubusercontent.com/{user}/{repo}/main/token-lists/minisign.pub

# Verify signature
minisign -V -p minisign.pub -m dbis-138.tokenlist.json -x dbis-138.tokenlist.json.sig
```

---

## CORS Configuration

If hosting the token list on a custom domain, ensure CORS headers are configured:

### Nginx Example

```nginx
location /lists/dbis-138.tokenlist.json {
    add_header Access-Control-Allow-Origin *;
    add_header Access-Control-Allow-Methods "GET, OPTIONS";
    add_header Content-Type application/json;
    add_header Cache-Control "public, max-age=3600";
    
    if ($request_method = OPTIONS) {
        add_header Access-Control-Allow-Origin *;
        add_header Access-Control-Allow-Methods "GET, OPTIONS";
        add_header Content-Length 0;
        add_header Content-Type text/plain;
        return 204;
    }
}
```

### Apache Example

```apache
<Location "/lists/dbis-138.tokenlist.json">
    Header set Access-Control-Allow-Origin "*"
    Header set Access-Control-Allow-Methods "GET, OPTIONS"
    Header set Content-Type "application/json"
    Header set Cache-Control "public, max-age=3600"
</Location>
```

---

## Rate Limiting

When fetching the token list:

- Use appropriate caching (recommended: 1 hour)
- Respect rate limits if using GitHub API
- Consider mirroring to CDN for high-traffic applications

### Caching Example

```javascript
const CACHE_KEY = 'dbis-token-list-v1.1.0';
const CACHE_TTL = 3600000; // 1 hour

async function getTokenListCached() {
  const cached = localStorage.getItem(CACHE_KEY);
  const cachedTime = localStorage.getItem(`${CACHE_KEY}-time`);
  
  if (cached && cachedTime && Date.now() - parseInt(cachedTime) < CACHE_TTL) {
    return JSON.parse(cached);
  }
  
  const response = await fetch('https://raw.githubusercontent.com/{user}/{repo}/main/token-lists/lists/dbis-138.tokenlist.json');
  const tokenList = await response.json();
  
  localStorage.setItem(CACHE_KEY, JSON.stringify(tokenList));
  localStorage.setItem(`${CACHE_KEY}-time`, Date.now().toString());
  
  return tokenList;
}
```

---

## Error Handling

Always handle errors when fetching token lists:

```javascript
async function getTokenList() {
  try {
    const response = await fetch('https://raw.githubusercontent.com/{user}/{repo}/main/token-lists/lists/dbis-138.tokenlist.json');
    
    if (!response.ok) {
      throw new Error(`HTTP ${response.status}: ${response.statusText}`);
    }
    
    const tokenList = await response.json();
    
    // Validate structure
    if (!tokenList.tokens || !Array.isArray(tokenList.tokens)) {
      throw new Error('Invalid token list format');
    }
    
    return tokenList;
  } catch (error) {
    console.error('Failed to fetch token list:', error);
    // Fallback to cached version or default list
    return null;
  }
}
```

---

## Support

For integration questions or issues:

- Create an issue in the repository
- Check existing documentation
- Contact DBIS team

---

**Last Updated**: 2025-12-22