Metamask

MetaMask Wallet

Installation

• Chrome: https://chrome.google.com/webstore/detail/metamask/nkbihfbeogaeaoehlefnkodbefgpgknn
• Firefox: https://addons.mozilla.org/firefox/addon/ether-metamask/
• Mobile: iOS App Store / Google Play
• Flask (dev): https://metamask.io/flask/

Add Popular Networks

Settings → Networks → Add Network

Polygon:

Network: Polygon Mainnet
RPC: https://polygon-rpc.com
Chain ID: 137
Symbol: MATIC
Explorer: https://polygonscan.com

Arbitrum:

Network: Arbitrum One
RPC: https://arb1.arbitrum.io/rpc
Chain ID: 42161
Symbol: ETH
Explorer: https://arbiscan.io

Optimism:

Network: Optimism
RPC: https://mainnet.optimism.io
Chain ID: 10
Symbol: ETH
Explorer: https://optimistic.etherscan.io

Base:

Network: Base
RPC: https://mainnet.base.org
Chain ID: 8453
Symbol: ETH
Explorer: https://basescan.org

BSC:

Network: BNB Smart Chain
RPC: https://bsc-dataseed.binance.org
Chain ID: 56
Symbol: BNB
Explorer: https://bscscan.com

Avalanche:

Network: Avalanche C-Chain
RPC: https://api.avax.network/ext/bc/C/rpc
Chain ID: 43114
Symbol: AVAX
Explorer: https://snowtrace.io

Import ERC-20 Token

Assets → Import Token → Custom Token

Common tokens (Ethereum):

USDC: 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48
USDT: 0xdAC17F958D2ee523a2206206994597C13D831ec7
DAI: 0x6B175474E89094C44Da98b954EescdeCB5BE3830
WETH: 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2
LINK: 0x514910771AF9Ca656af840dff83E8264EcF986CA
UNI: 0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984

Check Balance (CLI)

ETH balance:

cast balance YOUR_ADDRESS --ether --rpc-url https://eth.llamarpc.com

Token balance:

cast call 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 \
  "balanceOf(address)(uint256)" YOUR_ADDRESS \
  --rpc-url https://eth.llamarpc.com

ENS Names

Resolve ENS:

cast resolve-name vitalik.eth --rpc-url https://eth.llamarpc.com

Reverse lookup:

cast lookup-address YOUR_ADDRESS --rpc-url https://eth.llamarpc.com

Gas Settings

Settings → Advanced → Advanced Gas Controls

Check current gas:

cast gas-price --rpc-url https://eth.llamarpc.com | xargs -I {} cast --to-unit {} gwei

Transaction History

Via Etherscan:

https://etherscan.io/address/YOUR_ADDRESS

Via CLI:

cast etherscan-source YOUR_ADDRESS --etherscan-api-key YOUR_KEY

Connected Sites

Settings → Connected Sites → Manage permissions

Account Management

Create account: Account menu → Create Account Import: Account menu → Import Account

Hardware Wallet

1. Connect Ledger/Trezor
2. Account menu → Connect Hardware Wallet
3. Select device and address

Custom Nonce

Settings → Advanced → Customize transaction nonce

Get current nonce:

cast nonce YOUR_ADDRESS --rpc-url https://eth.llamarpc.com

Speed Up / Cancel Transaction

Pending tx → Speed Up or Cancel

Replace with CLI:

# Check pending nonce
cast nonce YOUR_ADDRESS --rpc-url https://eth.llamarpc.com

Export Account

Account menu → Account details → Export

Network RPC Endpoints

Troubleshooting

Stuck transaction:

# Get pending nonce
cast nonce YOUR_ADDRESS --pending --rpc-url https://eth.llamarpc.com

Then send 0 ETH to yourself with same nonce + higher gas

Wrong token balance: Assets → Refresh list, or reimport token

Network not connecting: Settings → Networks → Edit RPC URL

Reset account: Settings → Advanced → Clear activity tab data

MetaMask Snaps

Extend functionality with Snaps: Settings → Snaps → Browse Snaps

Popular snaps:

• Transaction Insights
• Account Management
• Interoperability

Mobile Sync

1. Mobile: Settings → Sync with Extension
2. Scan QR code from extension
3. Or use same recovery phrase

Security Tips

• Never share recovery phrase
• Verify URLs before connecting
• Review permissions before approving
• Use hardware wallet for large amounts
• Enable phishing detection

Notes

• MetaMask is EVM-only (Ethereum and compatible chains)
• Default network is Ethereum mainnet
• Supports EIP-1559 transactions
• Built-in swap via aggregators
• Mobile has built-in browser