fix: better error handling for derive missing chains

- Throw error when ALL chain derivations fail (was silent)
- Show descriptive success message with chain names
- Show error when no addresses derived
- Improves UX feedback on settings page

Author: ralyodio

scripts/derive-platform-fees.ts

@@ -0,0 +1,39 @@
+import { deriveKeyForChain } from '../src/lib/web-wallet/keys';
+import * as fs from 'fs';
+import * as path from 'path';
+
+const envPath = path.join(process.cwd(), '.env.prod');
+const envContent = fs.readFileSync(envPath, 'utf-8');
+
+// Parse all SYSTEM_MNEMONIC entries
+const mnemonics: Record<string, string> = {};
+for (const line of envContent.split('\n')) {
+  const match = line.match(/^SYSTEM_MNEMONIC_(\w+)="([^"]+)"/);
+  if (match) {
+    mnemonics[match[1]] = match[2];
+  }
+}
+
+async function main() {
+  console.log('# Derived PLATFORM_FEE_WALLET addresses from SYSTEM_MNEMONIC\n');
+  
+  const chains = ['BTC', 'BCH', 'ETH', 'POL', 'SOL', 'DOGE', 'XRP', 'ADA', 'BNB', 
+                  'USDC_ETH', 'USDC_POL', 'USDC_SOL', 'USDT_ETH', 'USDT_POL', 'USDT_SOL'];
+  
+  for (const chain of chains) {
+    const mnemonic = mnemonics[chain];
+    if (!mnemonic) {
+      console.log(`# SKIP ${chain}: no SYSTEM_MNEMONIC_${chain} found`);
+      continue;
+    }
+    
+    try {
+      const key = await deriveKeyForChain(mnemonic, chain as any, 0);
+      console.log(`PLATFORM_FEE_WALLET_${chain}=${key.address}`);
+    } catch (err: any) {
+      console.log(`# ERROR ${chain}: ${err.message}`);
+    }
+  }
+}
+
+main();

scripts/gen-platform-addrs.ts

@@ -0,0 +1,21 @@
+import { deriveKeyForChain, generateMnemonic } from '../src/lib/web-wallet/keys';
+
+async function main() {
+  const mnemonic = generateMnemonic(12);
+  console.log('# PLATFORM SEED PHRASE (SAVE THIS SECURELY!)');
+  console.log(`PLATFORM_SEEDPHRASE="${mnemonic}"`);
+  console.log('\n# Platform Fee Wallet Addresses\n');
+
+  const chains = ['BTC', 'BCH', 'ETH', 'POL', 'SOL', 'DOGE', 'XRP', 'ADA', 'BNB'] as const;
+
+  for (const chain of chains) {
+    try {
+      const key = await deriveKeyForChain(mnemonic, chain, 0);
+      console.log(`PLATFORM_FEE_WALLET_${chain}=${key.address}`);
+    } catch (err: any) {
+      console.error(`# ERROR ${chain}: ${err.message}`);
+    }
+  }
+}
+
+main();

src/app/web-wallet/settings/page.tsx

@@ -79,7 +79,7 @@ export default function SettingsPage() {
   const [missingChains, setMissingChains] = useState<string[]>([]);
   const [missingChainsLoading, setMissingChainsLoading] = useState(false);
   const [derivingChains, setDerivingChains] = useState(false);
-  const [deriveSuccess, setDeriveSuccess] = useState(false);
+  const [deriveSuccess, setDeriveSuccess] = useState('');
   const [deriveError, setDeriveError] = useState('');
 
   useEffect(() => {
@@ -141,18 +141,21 @@ export default function SettingsPage() {
   const handleDeriveMissingChains = async () => {
     if (!wallet) return;
     setDeriveError('');
-    setDeriveSuccess(false);
+    setDeriveSuccess('');
     setDerivingChains(true);
 
     try {
       const results = await wallet.deriveMissingChains();
       if (results.length > 0) {
-        setDeriveSuccess(true);
+        const chains = results.map(r => r.chain).join(', ');
+        setDeriveSuccess(`Successfully derived ${results.length} address${results.length > 1 ? 'es' : ''}: ${chains}`);
         // Refresh stored chains list and UI
         await refreshChains();
         // Reload missing chains (should be empty now)
         await loadMissingChains();
-        setTimeout(() => setDeriveSuccess(false), 3000);
+        setTimeout(() => setDeriveSuccess(''), 5000);
+      } else {
+        setDeriveError('No new addresses were derived. Chains may already exist.');
       }
     } catch (err) {
       console.error('Failed to derive missing chains:', err);
@@ -419,7 +422,7 @@ export default function SettingsPage() {
                 )}
                 {deriveSuccess && (
                   <p className="text-xs text-green-400" role="status">
-                    Successfully derived addresses for missing chains!
+                    {deriveSuccess}
                   </p>
                 )}
 

src/lib/wallet-sdk/wallet.ts

@@ -341,16 +341,30 @@ export class Wallet {
 
     // Derive addresses for each missing chain
     const results: DeriveAddressResult[] = [];
+    const failures: { chain: WalletChain; error: string }[] = [];
+    
     for (const chain of missingChains) {
       try {
         const result = await this.deriveAddress(chain, 0);
         results.push(result);
       } catch (err) {
+        const errorMsg = err instanceof Error ? err.message : String(err);
         console.error(`[Wallet] Failed to derive ${chain}:`, err);
-        // Continue with other chains even if one fails
+        failures.push({ chain, error: errorMsg });
       }
     }
 
+    // If ALL chains failed, throw an error with details
+    if (results.length === 0 && failures.length > 0) {
+      const failedChains = failures.map(f => f.chain).join(', ');
+      const firstError = failures[0].error;
+      throw new WalletSDKError(
+        'DERIVE_FAILED',
+        `Failed to derive addresses for: ${failedChains}. Error: ${firstError}`,
+        500
+      );
+    }
+
     return results;
   }