> ## Documentation Index > Fetch the complete documentation index at: https://docs.biconomy.io/llms.txt > Use this file to discover all available pages before exploring further. # How it works > The maker brings a price and inventory. Biconomy runs everything else. ## Where the maker plugs in The maker brings prices and inventory. Biconomy provides the contracts, the live book, the gas, the risk controls, the monitoring and the aggregator demand. The maker brings prices and inventory. Biconomy provides the contracts, the live book, the gas, the risk controls, the monitoring and the aggregator demand. The maker brings prices and inventory. Biconomy provides the contracts, the live book, the gas, the risk controls, the monitoring and the aggregator demand. The maker brings prices and inventory. Biconomy provides the contracts, the live book, the gas, the risk controls, the monitoring and the aggregator demand. | Maker | Biconomy | | ---------------------------------------------------------- | ------------------------------------------------------------------------- | | Signs a price ladder and streams it over one WebSocket | Writes it onchain, refreshes it before it expires, pays every transaction | | Holds inventory in a contract it owns | Settles fills from it at the signed prices | | Switches on the protections it wants, from the same stream | Enforces them in the contract | | | Runs the venue aggregators quote and swap against | The maker's pricing has no gas line and no infrastructure cost. The maker models spread and inventory. ## The ladder A price ladder for WETH/USDC: cumulative sizes 2, 5, 12 and 20 WETH at 2000.00, 1999.40, 1998.20 and 1995.50 USDC. A price ladder for WETH/USDC: cumulative sizes 2, 5, 12 and 20 WETH at 2000.00, 1999.40, 1998.20 and 1995.50 USDC. A price ladder for WETH/USDC: cumulative sizes 2, 5, 12 and 20 WETH at 2000.00, 1999.40, 1998.20 and 1995.50 USDC. A price ladder for WETH/USDC: cumulative sizes 2, 5, 12 and 20 WETH at 2000.00, 1999.40, 1998.20 and 1995.50 USDC. A ladder is up to 20 steps of size and price for one direction of one pair. Aggregators read it from the chain with no adapter. ## Two modes Both use the same ladder and the same connection. They differ in what the maker resends when the price moves. Rewrite sends the whole ladder on every update. Reprice sends the ladder once, then a single price number on every update. Rewrite sends the whole ladder on every update. Reprice sends the ladder once, then a single price number on every update. Rewrite sends the whole ladder on every update. Reprice sends the ladder once, then a single price number on every update. Rewrite sends the whole ladder on every update. Reprice sends the ladder once, then a single price number on every update. | | Rewrite | Reprice | | ------------ | ------------------- | ---------------------- | | Sends | full ladder | sizes once, then price | | Bought steps | come back | stay taken | | Suits | full-ladder engines | frequent reprices | The same ladder after 5 WETH was bought: Rewrite puts the sold steps back on the market, Reprice keeps them taken. The same ladder after 5 WETH was bought: Rewrite puts the sold steps back on the market, Reprice keeps them taken. The same ladder after 5 WETH was bought: Rewrite puts the sold steps back on the market, Reprice keeps them taken. The same ladder after 5 WETH was bought: Rewrite puts the sold steps back on the market, Reprice keeps them taken. Both modes moved every price. Rewrite also put the 5 WETH already sold back on the market. The mode is set per pair. ## Protections Four dials, off by default, enforced by the contract. Four protections: block cap, age fade, move premium and auto-dark. Four protections: block cap, age fade, move premium and auto-dark. Four protections: block cap, age fade, move premium and auto-dark. Four protections: block cap, age fade, move premium and auto-dark. | Dial | Effect | | ------------ | ------------------------------------------------------------- | | Block cap | Maximum the maker's book fills in one block. | | Age fade | Price widens with the square root of the quote's age. | | Move premium | Extra margin for the first blocks after a price change. | | Auto-dark | Each message has an expiry. After it, the book stops quoting. | Settings are on [Risk and inventory](/propamm/makers/risk-and-inventory). ## Fills and fees | | | | ---------------------- | -------------------------------------------------------------------------------------------------------------------------------- | | Quote vs fill | The venue quotes from the stored ladder that fills the trade. A swap that delivers less than the taker's `minAmountOut` reverts. | | Listing fee | None | | Routing fee for makers | None. An aggregator's fee comes out of the taker's output. | | Maker receives | The signed price |