How to Fix MetaMask Pending Transactions

# (MetaMask suggests a small gas increase, but if the network is congested,
#  even the increased gas may not be enough)

# 1. In MetaMask, click on the pending transaction
# 2. Click "Speed Up"
# 3. Click "Edit" next to gas price
# 4. Set gas price to at least 2x the current base fee + priority fee
# 5. Confirm

# 1. In MetaMask, click the pending transaction
# 2. Click "Cancel"
# 3. Confirm the cancellation
# (this sends a 0 ETH transaction with the same nonce and higher gas)

// Using ethers.js:
const tx = {
    to: "0x0000000000000000000000000000000000000000",
    value: 0,
    nonce: stuckNonce,  // same nonce as the stuck transaction
    gasLimit: 21000,
    maxPriorityFeePerGas: ethers.parseUnits("50", "gwei"),
    maxFeePerGas: ethers.parseUnits("100", "gwei"),
};
const replacementTx = await signer.sendTransaction(tx);
await replacementTx.wait();
// (this replaces the stuck transaction)

# MetaMask Settings → Advanced → Clear activity tab data
# This clears the local transaction history (does not affect the blockchain)
# The transaction may still be pending on-chain

// Get the current nonce from an external block explorer:
// etherscan.io/address/YOUR_ADDRESS → check "Nonce" tab

// In ethers.js, manually set the nonce:
const currentNonce = await provider.getTransactionCount(signer.address);
const tx = await signer.sendTransaction({
    to: "0x...",
    value: ethers.parseEther("0.1"),
    nonce: currentNonce,  // use the latest nonce
    gasLimit: 21000,
});

// Error: "replacement transaction underpriced"
// (the gas price on the replacement is not high enough)

const stuckTx = await provider.getTransaction(stuckTxHash);
const minGasPrice = stuckTx.gasPrice * 110n / 100n;  // 10% more
const replacement = await signer.sendTransaction({
    to: "0x0000000000000000000000000000000000000000",
    value: 0,
    nonce: stuckTx.nonce,
    gasPrice: minGasPrice,
    gasLimit: 21000,
});

// Transaction with nonce 5 is stuck → nonce 6 and 7 also cannot proceed
// (Ethereum processes transactions in nonce order)

// Cancel all transactions from nonce startNonce to currentNonce:
for (let nonce = startNonce; nonce < currentNonce; nonce++) {
    const pendingTx = await provider.getTransaction(signer.address, nonce);
    if (pendingTx && pendingTx.blockNumber === null) {
        // Send a 0 ETH replacement with higher gas
        await signer.sendTransaction({
            to: "0x0000000000000000000000000000000000000000",
            value: 0,
            nonce: nonce,
            gasPrice: pendingTx.gasPrice * 120n / 100n,
            gasLimit: 21000,
        });
    }
}