Overview

Backburn is a way to send a Solana trade. The MEV the trade creates comes back to the vault of the token traded, and the vault’s SOL leaves only by burning that token.

What happens to a trade

A swap shifts the price in the pool it trades against, and the gap it opens is worth money to whoever closes it. A searcher closes it with a backrun, a transaction placed directly after yours. With Helius Backrun Rebates, a transaction sent with a rebate-address gets 50% of that backrun’s profit paid to the address, in SOL, in the same block.

Backburn sets that address to the vault of the token you trade. Your swap is the same swap: built through Jupiter, signed by your wallet, at the same price. What changes is where the rebate goes.

  1. Jupiter routes the swap, and Backburn sets a fee plan for that exact transaction.
  2. You sign in your wallet. Backburn hands the signed transaction to Helius, naming the token’s vault as rebate-address, with mev-protect=true.
  3. When a backrun follows the trade into the block, the vault is paid its rebate there and then.

The vault

A vault is one program account per mint. Everything it holds beyond its own rent came from that token’s trades, and the only instruction that pays it out is burn, which burns that same mint. Anyone can open a vault for any mint; a token’s first swap through Backburn opens it.

The pairThe rebate goes to
Token and a base assetthe token’s vault
Token to tokenthe vault of the token bought
Base asset to base assetthe BACKBURN vault

Base assets are SOL, USDC, USDT.

The burn

When a vault holds the minimum lot, anyone starts its auction. The auction offers the vault’s SOL as one lot and asks for an amount of the token. The ask halves every half-life until a burner delivers it. The delivered tokens are burned and the burner takes the lot. Burn auction has the rule and worked numbers.

Each burn is therefore a market buy of the token, funded by the token’s own trading.

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