Introduction

What it is

The LCX DeFi product line. Nothing in this API changes who holds your assets: it prices, and it hands back calldata for you to sign yourself.

LCX Liberty DEX is a DEX aggregator, and this is its API. Give it a chain, a pair and an amount. It returns the best route it can find across the pools it indexes, plus the calldata to execute that route if you ask for it.

What separates it from most swap APIs is where the answer comes from. LCX Liberty DEX runs its own pool index: more than 450,000 pools and 400,000 tokens across every chain we index and 40+ venues, read from chain state rather than bought from another aggregator and resold. A quote is computed against pool reserves we hold, so the route we return is the route that executes. GET /v1/stats reports the exact counts as of right now.

Quoting and execution both cover every chain we index. GET /v1/chains carries routerDeployed per chain: branch on that field rather than on a list you keep yourself, and a chain we add later needs no change on your side.

Coverage

The same address on every chain, and that is deliberate rather than a coincidence of deployment: one address to allow, one to verify, and nothing per chain for an integrator to keep straight. It is a UUPS proxy, so it is stable across upgrades. That is the address an ERC-20 approval is granted to, and it is what /v1/quote returns as spender. Read it from the quote rather than pinning it here: a quote that ever named a different spender is the one that is right, and code that trusts this page instead would approve the wrong contract.

Fourteen venues are indexed: Uniswap V2, V3 and V4, SushiSwap and SushiSwap V3, PancakeSwap V2 and V3, ShibaSwap, Curve, Balancer, Aerodrome and Aerodrome Slipstream on Base, and Velodrome and Velodrome Slipstream on OP Mainnet. Behind those keys sit five families of pool math: constant product, concentrated liquidity, Solidly stable and volatile, Curve StableSwap, and Balancer weighted. Uniswap V4 is a fourteenth key rather than a sixth family: its curve is V3’s, so it reuses that tick walk, and what differs is only where the state is read from.

V4 is routed like any other venue. It settles through the singleton’s unlock callback rather than a pool address, because a V4 pool does not have one since every pool lives inside a single PoolManager. The router implements that callback, so a V4 hop quotes and executes exactly as a V3 hop does.

includeUnexecutable still exists for venues the router cannot settle. There are none today, so it changes nothing; it stays because the next family we index will be unexecutable before it is executable, and a quote should never be an offer we cannot honour.

GET /v1/chains returns the live list with per-chain index freshness, and it never counts against your quota. See Chains & status.

What it does not do

• It does not hold funds. There is no deposit, no custody and no account balance. You send the transaction from your own wallet.
• It does not sign or broadcast. The API returns { to, data, value }; signing and sending stay entirely on your side.
• It does not send the approval for you. We return the exact spender; the approve is yours to send. See Approvals.
• It takes no cut of the swap. There is no integrator fee and no positive-slippage capture. swapFeeBps on GET /v1/stats is 0. You pay for API calls, not for volume.
• It does not execute everywhere it quotes. The router contract is live on Ethereum. On the other chains a quote comes back with spender: null and there is nothing to sign.

Where to go next

• Quickstart gets you a priced route in about a minute, with no key.
• Quotes & execution is the model to have in your head before you write the integration.
• API reference lists every endpoint and every field it returns.