metamask-integration/docs/METAMASK_WETH9_FIX_INSTRUCTIONS.md

MetaMask WETH9 Display Fix Instructions

Date: $(date)
Issue: MetaMask showing "6,000,000,000.0T WETH" instead of "6 WETH"
Root Cause: WETH9 contract's decimals() returns 0 instead of 18

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🔍 Problem Confirmed

Root Cause: The WETH9 contract at 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2 has a decimals() function that returns 0x0 instead of 18.

When MetaMask reads the token balance:

• It gets: 6,000,000,000,000,000,000 wei (raw value)
• It expects: decimals = 18 to format correctly
• It gets: decimals = 0 (incorrect)
• Result: Displays as 6,000,000,000.0T WETH ❌

Actual Balance: 6 WETH ✅

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✅ Solution: Manual Token Import in MetaMask

Since the contract's decimals() function is incorrect, you need to manually specify the correct decimals when importing the token.

Step-by-Step Instructions

1. Open MetaMask

   • Make sure you're connected to "Defi Oracle Meta Mainnet" (ChainID 138)

2. Go to Import Tokens

   • Click on the token list (where you see "Wrapped Ether")
   • Scroll down and click "Import tokens"
   • Or go to: Settings → Tokens → Import tokens

3. Enter Token Details

   • Token Contract Address: 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2
   • Token Symbol: WETH
   • Decimals of Precision: 18 ⚠️ IMPORTANT: Set this to 18
   • Click "Add Custom Token"

4. Verify

   • The token should now display as "6 WETH" instead of "6,000,000,000.0T WETH"
   • Note: MetaMask only lets you hide an asset, not remove it. If WETH already shows the wrong amount (e.g. "500.00T WETH"): open the asset → ⋮ menu → Hide WETH, then add the token again via the explorer’s "Add to wallet" button or manual import above with Decimals: 18. The new entry will use the correct decimals.

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📱 MetaMask: Hide, then re-add with correct decimals

MetaMask does not offer "Remove token" — only Hide [asset] (⋮ menu on the token). To fix a wrong WETH display (e.g. "500.00T WETH" instead of "500 WETH"):

1. Open the WETH asset → tap the ⋮ menu → Hide WETH.
2. Add the token again so MetaMask gets decimals: 18:
   • Option A: Go to https://explorer.d-bis.org/weth , connect MetaMask, and click the wallet icon next to the WETH9 contract. Confirm "Add token." The explorer sends decimals 18 and symbol WETH.
   • Option B: In MetaMask, Import tokens → Custom token: Address 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2, Symbol WETH, Decimals 18 → Add.

The (re-)added token should then show the correct balance (e.g. 500 WETH).

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🔄 Alternative: Use Token List

If you have access to host a token list JSON file:

1. Use the Updated Token List

   • File: docs/METAMASK_TOKEN_LIST.json
   • Now includes WETH9 with correct decimals (18)

2. Host the Token List

   • Upload to GitHub, IPFS, or any public URL
   • Example: https://your-domain.com/token-list.json

3. Add to MetaMask

   • Settings → Security & Privacy → Token Lists
   • Add custom token list URL
   • Or import directly in dApp

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🌐 Explorer "Add to wallet" (same as MetaMask display)

The SolaceScanScout explorer (https://explorer.d-bis.org) adds WETH9 and WETH10 to MetaMask with decimals: 18 and symbol: WETH when you click the wallet icon next to a token (WETH page, Tokens list, or token detail). So MetaMask will display balances the same way as the explorer (e.g. "100 WETH", not "100T" or raw wei).

• WETH page (Tools → WETH): wallet icon next to each contract address.
• Tokens list and token detail: wallet icon to add that token with correct decimals and symbol.

Our token lists (METAMASK_TOKEN_LIST.json, config/token-list.json, provider token list) also use symbol: WETH and decimals: 18 for both WETH9 and WETH10 so any app using these lists will show the same as the explorer.

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📊 Verification

After fixing, verify the display:

1. Check Balance Display

   • Should show: 6 WETH or 6.0 WETH ✅
   • Should NOT show: 6,000,000,000.0T WETH ❌

2. Verify On-Chain Balance (Optional)

   cast call 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2 \
     "balanceOf(address)" <YOUR_ADDRESS> \
     --rpc-url http://192.168.11.250:8545 | \
     xargs -I {} cast --to-unit {} ether
   # Should output: 6
   

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🐛 Why This Happens

WETH9 Contract Issue

The WETH9 contract is an older implementation that:

• ✅ Implements ERC-20 balanceOf(), transfer(), etc.
• ❌ Does NOT properly implement decimals() (returns 0)
• ❌ May not implement other ERC-20 optional functions

MetaMask Behavior

When MetaMask encounters a token with decimals = 0:

1. It reads the raw balance: 6000000000000000000
2. Without proper decimals, it doesn't know to divide by 10¹⁸
3. It formats the number incorrectly
4. Result: 6,000,000,000.0T (treating it as a very large number)

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✅ Expected Result

After applying the fix:

• Before: 6,000,000,000.0T WETH ❌
• After: 6 WETH or 6.0 WETH ✅

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📝 Notes

• This is a display issue only - your actual balance is correct on-chain
• Transactions will work correctly regardless of the display
• The fix only affects how MetaMask displays the balance
• Other wallets may have the same issue if they rely on decimals()

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🔗 Related Documentation

• MetaMask WETH9 Display Bug Analysis
• WETH9 Creation Analysis
• MetaMask Token List

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Last Updated: $(date)