Overview

Latch docs

Latch is a concentrated-liquidity AMM on Solana where each pool can take one hook program. These pages cover trading and providing liquidity in the app, how hooks work, and how to build on Latch.

Every pool on Latch is a concentrated-liquidity pool. When it is created, a pool may name one hook program and a permission mask. The hook runs at fixed points of every swap and liquidity change, and the mask says which of those points it may use and what it may change. Both are fixed for the life of the pool.

Every pool shares one program and one way of reading accounts, with a different hook in each. A dynamic fee, an on-chain TWAP and a range order ship as built-in hooks. Anything else that fits the interface can be written as a hook, without a new AMM.

Start here#

SwapQuote a trade on every pool of a pair at once and take the best fill.Provide liquidityPick a price range, deposit, collect fees, withdraw.Create a poolChoose two tokens, a starting price and the hook to plug in.How Latch worksPools, hooks, permissions and the order a swap runs in.

The built-in hooks#

Dynamic feeRaises the fee after the price moves and lets it decay while trading is calm.TWAP oracleRecords the pool's tick around every swap. Anyone can read a time-weighted mean.Range orderOne owner sells through a fixed price range, like a limit order.No-opCalled around every swap and changes nothing. The baseline for what a hook costs.

Build on Latch#

Write a hookThe callback, the reply and the bounds your program runs inside.Route through LatchDiscover pools, resolve hook accounts and quote swaps from a router.TypeScript SDKDecoders, instruction builders and an exact port of the pool math.HTTP APIRead pools and positions, quote, and prepare unsigned transactions.

Limits worth knowing first#

Some limits are part of the design:

A pool holds at most 64 initialized tick boundaries. Once all 64 are in use, a deposit into a range that needs a new boundary fails.
A hook can use at most eight extra accounts, listed literally when the pool is created.
Classic SPL tokens are supported, including wrapped SOL and stablecoins such as USDC and USDT. Token-2022 mints, frozen token accounts and token accounts with a delegate or close authority are rejected.
Positions belong to the wallet that opened them. They are program accounts, not transferable NFTs.
A pool's hook, permissions and caps never change. A different setup is a new pool.