Rulebook
Eight rules, in the order a race runs. Every number here is a bound in the program.
Why the vault finishes first
On pump.fun the first buyers are bots: they land in the same block as the coin and the next few, and everyone after them pays their premium.
A Frontrun vault is filled before the coin exists. At launch ONE transaction holds the dev's pump.fun create_v2 and, right after it, our launch instruction, which buys the coin with the whole vault. The mint does not exist before that transaction and only the dev holds its key, so nobody can buy before the vault.
Every depositor gets the coin's first price. The site shows the proof for each launch: the signature, the slot, the two instructions and what the next buyers paid.
A race, step by step
- Open. The dev opens a vault for a coin that does not exist yet: name, ticker, picture, launch time, cap, max per wallet, unlock time. The metadata hash is pinned in the vault: the coin that launches must match it.
- Deposit. Anyone deposits SOL into a program account (not the dev's wallet) until the launch time. Withdrawals stay open until 5 minutes before launch.
- Launch. In the 30-minute window after the launch time the dev sends one transaction:
create_v2, thenlaunch. The program checks the create instruction is right before it, for this mint, by this dev, with the pinned metadata, on an untouched curve, and that no other pump.fun trade comes before it. - Unlock. The bought tokens unlock to depositors linearly over 15 to 30 minutes. Claim any time; unclaimed tokens wait in the vault.
- Refund. No launch in the window, the dev cancels, or the coin is created outside the vault: refunds open and every deposit comes back whole.
Your share
The vault buys with min(total, cap), less the vault fee. Your tokens = bought tokens x your deposit / total. Unlocked = your tokens x min(1, time since launch / unlock time).
If deposits went above the cap, the part that was not spent comes back to everyone pro rata with the first claim: change = (total - spent) x your deposit / total. All math is integer and rounds down; rounding dust is burned or swept when the vault closes.
Parameters
| Parameter | Value | Bound in the program |
|---|---|---|
| Cap | 20 SOL default, 5 to 40 | never above 40 SOL |
| Max per wallet | cap / 10 default | 1% to 100% of cap |
| Oversubscription | deposits up to 3x cap | 1x to 5x |
| Min deposit | 0.01 SOL | 0.001 to 1 SOL |
| Lead time | at least 10 min | up to 7 days |
| Withdraw lock | 5 min before launch | 0 to 30 min |
| Launch window | 30 min | 10 to 120 min |
| Unlock | 20 min default, dev picks 15 to 30 | 15 to 30 min |
| Vault fee | 0.5% of what the vault spends | never above 0.5% |
Parameter changes apply to new vaults only and wait 24 hours on chain before they can take effect.
Who can touch what
- Admin can pause new vaults and deposits, propose parameters (24 h timelock), a new treasury (3 day timelock) and a new admin. There is no instruction that moves deposited SOL or bought tokens anywhere but to depositors.
- The launch caller lends a little rent headroom for pump.fun's first-buyer accounts and gets it back when the vault closes. Amounts are fixed on chain.
- The service holds a pre-signed launch only if the dev asks it to. Worst case it does not send: the dev launches by hand, or refunds open. It cannot move money.
- A keeper opens refunds for expired vaults, refunds deposits and closes empty vaults. Anyone can call the same instructions.
Honest limits
- pump.fun cannot gate buyers. From the next transaction on, the coin is a normal pump coin. The vault is first, not alone.
- The dev holds the mint key: he can create the coin outside the vault and buy it himself. The vault can then never launch; refunds open at once and the dev is marked on his vault page.
- Max per wallet is per wallet; one person can split a deposit across wallets.
- pump.fun can move a coin's creator fee (its own takeover rules). That is the dev's risk, not the vault's.
- The program is upgradeable and has not had an external audit yet.
For the starter (the dev)
Opening a vault creates the coin's mint key in your browser. Download it: the launch transaction must be signed by it. Keep the page or load the file again at launch.
Two ways to launch: hold the launch button on the vault page when the window opens, or pre-sign before it. Pre-signing uses a durable nonce you own, so the signature stays valid; the service sends it the second the window opens and retries for a minute. A pre-signed launch names the fee treasury: if the treasury changes before launch (3 day timelock, announced on chain), sign it again or use the button.
You pay normal transaction fees and lend a small rent headroom for pump.fun's first-buyer accounts (under 0.01 SOL). It comes back when the vault closes, except about 0.001 SOL that stays in your own pump.fun creator vault.
$FRONTRUN
The coin of this site, launched on pump.fun. Its creator fee is split 80% dev, 20% infrastructure. Holding $FRONTRUN is not required to use a vault.