Quotes and routing

GET /v1/quote is a live read of every venue on the chain for one pair and size. It is not a price feed: the answer is what you would get right now, on the route the engine would execute.

How a route is found

1. Every single-hop venue is quoted in parallel — Uniswap V3 and V4 pools (including hooked launchpad pools on Arc), V2 pairs, and the forks the engine knows.
2. Splits. Within a hop the order can be split across venues (say 90 % in one pool and 10 % in another) when that improves the output beyond a small threshold, and only across distinct pools.
3. Composed hops. When no direct pool wins, the engine composes the best A → anchor leg with the best anchor → B leg through the chain’s anchors (USDC and EURC on Arc; WETH and USDG on Robinhood Chain).
4. Safety gates. Routes over 50 % impact are dropped, hooks the engine has not verified are not routed, and a paused venue is muted.

The winner is returned with one routePlan entry per leg, each carrying the venue id, the pool, the amounts, and the adapter and calldata the router will use. Do not construct venue logic from these fields — pass the whole body to /swap.

Reading the numbers

Field	Meaning
outputAmount	What the route returns before the protocol fee, smallest unit.
feeBps · feeAmount · feeTier	The protocol fee on the output token, per token, from the on-chain fee collector: 5 bps by default on every chain, 0 on USDC / EURC (Arc) and WETH / USDG / stocks (4663), capped at 100. feeAmount is deducted on-chain from outputAmount.
otherAmountThreshold	The minimum output after fee and slippage — the number the transaction enforces. Positive slippage goes to the user.
priceImpactPct	Percent, against the spot rate of the same route. Display only.
gasEstimate	From the venue quoter or an RPC estimate.
blockNumber	The block the venues were read at.

A quote is good for about 30 seconds. If the user waited longer, quote again before building.

No route

An empty routePlan with outputAmount: "0" is a real answer: nothing on the chain fills this size. noRouteReason says INSUFFICIENT_LIQUIDITY (the pair routes at a smaller size — try one) or NO_POOLS (no venue holds the pair). The engine never fabricates a price.

Slippage

slippageBps on the quote sets otherAmountThreshold. On /swap it is a consistency check only: the signed minimum is the quote’s threshold, which already folds in venue-specific widening the swap builder cannot re-derive. Sending a different value returns 400 SLIPPAGE_MISMATCH. Want tighter or looser? Quote again.

The fast frame

fast=1 returns a single-hop quote in about 400 ms with preliminary: true. Use it to paint a first number, run the full quote alongside, and replace. Never build a transaction from a preliminary quote.

Debug: one venue

only=<venue id> restricts routing to one venue and returns its raw quote before the safety gates. It needs an API key, because a shared link with ?only= would hand a user exactly the route the gate refuses.

Simulate before you sign

POST /v1/swap/simulate with the built transaction runs eth_call from the user’s address and estimates gas. A revert comes back decoded (NotRouter, a paused market, allowance or balance) so the wallet never opens on a doomed transaction. An allowance revert is advisory: approve, then swap.

Where fees go

The fee is read per output token from the on-chain fee collector: 5 bps by default on every chain since 2026-10-02, 0 on the stablecoins and majors each chain exempts, capped at 100. It does not change with a token’s age. A referrer passed as feeAccount on POST /v1/swap earns 50 % of the fee on that swap; /v1/meta/* and the MCP tools take no referrer. Quotes and API usage are free.