Burst vs Atomic: Which Launch Mode to Use on Base

Two ways to launch on a chain without bundles

Base has no public mempool and no bundle market. Transactions go privately to the sequencer, which orders them inside each 200 ms Flashblock by priority fee and then by arrival. Public Base RPCs and the sequencer endpoint reject eth_sendBundle.

TokenBundle offers two launch modes that work within those rules. You pick one at the Execute step of Custom Bundle, after the wallets are funded and the plan has been reviewed.

How Burst mode works

Burst is the default. The whitelist call, the open-trading call and one buy per wallet are built as separate transactions and signed up front. They are dry-run in order with eth_simulateV1, so if a transaction would fail, you see which one and from which sender before anything is sent.

The transactions then go out as one ordered JSON-RPC batch straight to the Base sequencer, each with the same priority fee. The buys land right behind the open, usually in the same Flashblock.

How Atomic mode works

Atomic, labeled Max protection, uses EIP-7702, which is live on Base since the Isthmus upgrade in May 2025. The Deployer sends one type-4 transaction to itself. It carries authorizations from the Deployer and every bundle wallet pointing at TokenBundle's LaunchDelegate contract.

Inside that transaction the Deployer makes the token calls (whitelist and openTrading), then calls each wallet's execute(), which runs that wallet's Uniswap V2 buy with the wallet's own ETH. The whole transaction lands or the whole transaction reverts, and nothing can land in between. Afterward every delegation is revoked, so the wallets are plain EOAs again.

Side-by-side comparison

What each mode guarantees

Burst is not atomic. A buy that misses the Flashblock of the open competes in the next one, where snipers who saw the open can be. With a token created by Deploy Token, the anti-snipe whitelist closes that gap: only whitelisted wallets can buy during the window, and Execute whitelists every bundle wallet before opening trading, so any other buy in the window reverts. That puts Burst at about 100% for those tokens. For someone else's token without a whitelist, Burst is about 99%.

Atomic removes the gap entirely, because there is no space between the open and the buys. The limit is gas: the 16,777,216 per-transaction gas cap from EIP-7825 fits about 80 wallets, which is 75 of your own plus service wallets. On a Base mainnet fork, an open plus 7 wallet buys used about 1.38M gas.

How to choose

• Use Burst with a Deploy Token contract when you want each buy to look organic on BaseScan; the whitelist window protects the launch.
• Use Atomic when you launch a token without a whitelist and want an all-or-nothing launch.
• Use Burst when you need more than 75 of your own wallets.
• Use Atomic only if you accept that all wallets appear inside one transaction and are visibly linked.

FAQ

• Which mode is the default on Base? Burst is the default. Atomic is offered at the Execute step as Max protection.
• Is Burst an atomic bundle? No. Each transaction stands alone, so a buy that misses the opening Flashblock competes in the next one.
• Why does Atomic have a wallet limit? Everything runs in one transaction, and the 16,777,216 per-transaction gas cap fits about 80 wallets, 75 of them your own.
• Who pays gas in Atomic mode? The Deployer pays all the gas for the single transaction, while each buy still uses the wallet's own ETH.
• Can people see my wallets are linked? In Atomic mode, yes, because all wallets appear inside one transaction on BaseScan. In Burst mode each buy is its own transaction.

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