Launch a token

import { toHex } from 'viem'
import { account } from './size.js'

/** CREATE2 salt. It only has to be unused by this account — any random 32 bytes. */
const salt = toHex(crypto.getRandomValues(new Uint8Array(32)))

export const params = {
  name: 'Example Coin',
  symbol: 'EXAMPLE',
  // A URL, not the image itself. Host the picture and put its link here —
  // uploading through size.fun gives you one, pinned to IPFS.
  logo: 'https://size.fun/api/img/0000000000000000000000000000000000000000000000000000000000000000',
  description: 'A coin that exists.',
  socials: {
    twitter: 'https://x.com/example',
    telegram: '',
    discord: '',
    website: '',
    farcaster: '',
  },
  // Where this launch's fees are paid. Changeable later, by this address only.
  creatorFeeRecipient: account.address,
  // 0 to 1000, charged on every trade on top of the 1% base fee and paid to you
  // in full. Frozen at launch: there is no setter for it afterwards.
  creatorTaxBps: 0,
  // Puts half of your share of the base fee into buying the coin back, on a
  // five-year vest. Can be turned on or off later.
  buybackEnabled: false,
  // 32 zero bytes waives the check on the launch terms. See "Pinning the terms".
  expectedEconomics: `0x${'00'.repeat(32)}` as `0x${string}`,
  salt,
} as const

import { parseEventLogs } from 'viem'
import {
  publicClient, walletClient, account,
  size, factoryAbi, OKB, LAUNCH_CONFIG_ID,
} from './size.js'
import { params } from './launch-params.js'

const launchFee = await publicClient.readContract({
  address: size.factory,
  abi: factoryAbi,
  functionName: 'launchFee',
})

// Simulating first does two things: it reverts here rather than on chain if
// anything about the parameters is wrong, and it hands back the token and curve
// addresses before the transaction has been sent.
const { request, result } = await publicClient.simulateContract({
  address: size.factory,
  abi: factoryAbi,
  functionName: 'launchToken',
  args: [params, LAUNCH_CONFIG_ID, OKB],
  value: launchFee,
  account,
})

const [token, curve] = result
console.log({ token, curve })

const hash = await walletClient.writeContract(request)
const receipt = await publicClient.waitForTransactionReceipt({ hash })

// The same two addresses, read back off the receipt.
const [launched] = parseEventLogs({
  abi: factoryAbi,
  eventName: 'TokenLaunched',
  logs: receipt.logs,
})
console.log(launched.args)

import { parseEther } from 'viem'
import {
  publicClient, walletClient, account,
  size, factoryAbi, launchAndBuyAbi, OKB, LAUNCH_CONFIG_ID,
} from './size.js'
import { params } from './launch-params.js'

/** What you want to spend on your own coin, in OKB. */
const quoteIn = parseEther('0.5')

const launchFee = await publicClient.readContract({
  address: size.factory,
  abi: factoryAbi,
  functionName: 'launchFee',
})

const { request, result } = await publicClient.simulateContract({
  address: size.launchAndBuy,
  abi: launchAndBuyAbi,
  functionName: 'launchAndBuy',
  args: [
    params,
    LAUNCH_CONFIG_ID,
    OKB,
    quoteIn,
    // No slippage bound is needed. The curve does not exist until this call
    // creates it, so there is no price for anyone else to move first.
    0n,
    // Who receives the tokens. Exempted from the snipe tax automatically.
    account.address,
    // Extra wallets to exempt, if a team is bundling its opening buys. Up to 31.
    [],
  ],
  // For a native launch the call carries both legs: the fee and the buy.
  value: launchFee + quoteIn,
  account,
})

const [token, curve, tokensOut] = result
console.log({ token, curve, tokensOut })

const hash = await walletClient.writeContract(request)
await publicClient.waitForTransactionReceipt({ hash })

args: [
  params,
  LAUNCH_CONFIG_ID,
  OKB,
  quoteIn,
  0n,
  account.address,
  ['0xabc…', '0xdef…'], // exempt as well; recipient is added for you
],

import { publicClient, size, factoryAbi, OKB, LAUNCH_CONFIG_ID } from './size.js'

/**
 * The launch terms — supply, fee, phantom reserve, threshold, the pool's fee
 * tier, the fee split — are protocol settings. They change rarely, but a change
 * landing between the moment you read them and the moment your launch mines
 * would silently give you different terms than the ones you agreed to.
 *
 * Passing this digest as `expectedEconomics` makes that case revert instead.
 * Passing 32 zero bytes waives the check, which is what the site does.
 */
export const expectedEconomics = await publicClient.readContract({
  address: size.factory,
  abi: factoryAbi,
  functionName: 'previewLaunchEconomics',
  args: [LAUNCH_CONFIG_ID, OKB],
})