Account: 0x123...
Nonce: 5 (has sent 5 transactions: 0, 1, 2, 3, 4)

Next valid transaction must have nonce = 5
Transaction with nonce 6 will be pending until nonce 5 is mined
Transaction with nonce 4 will be rejected (already used)

import * as Nonce from '@tevm/voltaire/Nonce'

// Universal constructor
const nonce = Nonce.from(42)

// Various input types
Nonce.from(42)        // from number
Nonce.from(42n)       // from bigint
Nonce.from("42")      // from string
Nonce.from("0x2a")    // from hex string

import * as Nonce from '@tevm/voltaire/Nonce'

const nonce = Nonce.from(42)

// To number
Nonce.toNumber(nonce)  // 42

// To bigint
Nonce.toBigInt(nonce)  // 42n

import * as Nonce from '@tevm/voltaire/Nonce'

const nonce = Nonce.from(42)

// Increment by 1
const next = Nonce.increment(nonce)
Nonce.toNumber(next)  // 43

import * as Nonce from '@tevm/voltaire/Nonce'

async function sendMultipleTransactions(
  rpcUrl: string,
  from: string,
  transactions: { to: string; value: bigint }[]
) {
  // Get current nonce
  const response = await fetch(rpcUrl, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      jsonrpc: '2.0',
      method: 'eth_getTransactionCount',
      params: [from, 'pending'],
      id: 1
    })
  })
  const { result } = await response.json()
  let nonce = Nonce.from(result)

  // Send each transaction with incrementing nonce
  for (const tx of transactions) {
    await sendTransaction({
      from,
      to: tx.to,
      value: tx.value,
      nonce: Nonce.toNumber(nonce)
    })
    nonce = Nonce.increment(nonce)
  }
}

import * as Nonce from '@tevm/voltaire/Nonce'

// To replace a pending transaction, use the same nonce
// with higher gas price
async function speedUpTransaction(
  originalTx: { nonce: number; gasPrice: bigint },
  newGasPrice: bigint
) {
  const nonce = Nonce.from(originalTx.nonce)

  return {
    nonce: Nonce.toNumber(nonce),  // Same nonce!
    gasPrice: newGasPrice,         // Higher gas price
    // ... other fields
  }
}

// To cancel, send 0 value to yourself with same nonce
async function cancelTransaction(
  originalNonce: number,
  from: string,
  gasPrice: bigint
) {
  const nonce = Nonce.from(originalNonce)

  return {
    nonce: Nonce.toNumber(nonce),
    to: from,              // Send to self
    value: 0n,             // Zero value
    gasPrice: gasPrice,    // Higher than original
  }
}

import * as Nonce from '@tevm/voltaire/Nonce'

async function getPendingTransactionCount(
  rpcUrl: string,
  address: string
): Promise<number> {
  // Get confirmed nonce
  const confirmedResponse = await fetch(rpcUrl, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      jsonrpc: '2.0',
      method: 'eth_getTransactionCount',
      params: [address, 'latest'],
      id: 1
    })
  })
  const { result: confirmed } = await confirmedResponse.json()

  // Get pending nonce
  const pendingResponse = await fetch(rpcUrl, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      jsonrpc: '2.0',
      method: 'eth_getTransactionCount',
      params: [address, 'pending'],
      id: 2
    })
  })
  const { result: pending } = await pendingResponse.json()

  const confirmedNonce = Nonce.from(confirmed)
  const pendingNonce = Nonce.from(pending)

  return Nonce.toNumber(pendingNonce) - Nonce.toNumber(confirmedNonce)
}

// Error: "nonce too low" or "replacement transaction underpriced"
// Cause: Trying to use a nonce that was already used
// Solution: Fetch current nonce from network

const nonce = await getAccountNonce(rpcUrl, address)

// Transaction stuck in pending
// Cause: Earlier nonce transaction failed/missing
// Solution: Fill the gap or cancel all pending

// If nonce 5 is pending but nonce 4 is missing,
// submit a transaction with nonce 4 first

// Problem: Multiple parts of app sending transactions
// Solution: Use a centralized nonce manager

// Bad: Each component fetches its own nonce
// Good: Single nonce manager tracks and assigns nonces