Fees & rebates

The standard batch-auction schedule has a 1 bp Ophis base fee. On eligible orders, Ophis also retains 80% of price improvement on volatile pairs, capped at 99 bps of volume, or 50% on stablecoin pairs, capped at 20 bps. On Optimism, Unichain, Robinhood Chain and Arc, this backend fee applies only to in-market orders. Out-of-market limit orders pay the signed base without this backend improvement fee. On CoW-hosted chains, CoW Protocol applies its own upstream fee policy separately.

The table separates Ophis and upstream batch-auction fees. It is not a total execution-cost estimate: gas, pool fees, price impact and bridge costs can also affect the net amount. Check the final route quote before signing.

The all-in cost, per chain

	Ophis-operated chains (Optimism, Unichain, Robinhood Chain, Arc)	CoW-hosted chains (10)
Ophis fee	0.01% base + 80% of price improvement (50% stables), capped at 0.99% (0.20% stables)	Same Ophis policy: 0.01% base + capped improvement capture
Upstream protocol fee	None	CoW Protocol volume fee: 0.02% (0.003% on correlated pairs such as stablecoins)
Base + upstream volume components	0.01%	0.03% volatile / 0.013% correlated stables
Price improvement	Trader receives the remainder after Ophis's capped capture; all improvement above the cap returns to the trader	Ophis's capped capture applies, and CoW Protocol's upstream improvement policy applies separately

Why the difference: on the 10 CoW-hosted chains, orders settle through CoW Protocol's hosted orderbook and solver network, which charges its own protocol fees on top of the Ophis fee. On Optimism, Unichain, Robinhood Chain, and Arc, Ophis operates the entire stack itself (settlement contracts, orderbook, solvers), so there is no upstream fee. The 1 bp base and capped price-improvement policy are the complete Ophis charge.

Arc price-improvement policy

Arc uses the same backend policy for in-market orders as the other Ophis-operated chains: 80% of reference-quote improvement capped at 99 bps, or 50% capped at 20 bps for recognized stablecoin pairs, including USDC/EURC. Eligibility follows the order's price relative to its reference quote, not the frontend's market/limit label. An out-of-market limit order has no backend improvement fee. The separate 1 bp base remains in signed appData; clients must not duplicate the backend improvement policy in appData.

Arc originally launched with an empty protocol-fee configuration. Historical base-only executions remain recorded at their original fees; enabling the standard policy does not recalculate past trades.

Arc settled trades are indexed for volume-tier and affiliate rebates under the same eligibility rules. Use SDK v0.4.4 or later for Arc referral tags. This does not enable an Arc own-fee payout guarantee.

How it works

• Volatile pairs add 80% of reference-quote improvement, capped at 99 bps.
• Stablecoin pairs add 50% of reference-quote improvement, capped at 20 bps.
• A 1 bp base fee is applied on every supported chain.
• On CoW-hosted chains, the upstream CoW Protocol fees in the table above are charged in addition; Ophis does not receive them.

Standard price-improvement capture

Solvers compete to fill your order. Price improvement is measured against the reference quote; surplus relative to your signed limit is a different measure when that limit includes slippage. Neither is a guaranteed return.

The capture is measured against the backend's reference quote, not against a loose user slippage limit. For volatile pairs Ophis retains 80%, until the fee reaches 99 bps of volume. For stablecoin pairs it retains 50%, until the fee reaches 20 bps. The separate 1 bp base fee always applies.

Where the order settles still matters:

• Optimism, Unichain, Robinhood Chain, and Arc: the backend applies the capped capture model to in-market orders as a protocol policy.
• CoW-hosted chains: the same Ophis policy is encoded in CIP-75 appData. CoW Protocol's own fee model also applies upstream. That upstream charge is not an Ophis fee and applies to every frontend using CoW-hosted settlement.

CoW applies protocol policies before partner policies, with iterative fee calculation. Do not add their capture percentages as if both apply independently to the original improvement. See CoW's current fee policy.

Bridge and conversion routes

NEAR Intents quotes, including the standalone externally funded flow, request a 3 bps Ophis app fee, alongside provider costs reflected in the quote. A direct NEAR deposit is not a batch-auction order and does not also use the 1 bp base and capped improvement schedule above. Direct Circle bridge and WBTC-conversion routes are not batch-auction swaps and must not be priced using the table above. Source approval/deposit, conversion and destination execution can require gas. See Networks & assets for route restrictions and recovery.

Comparing execution costs

Compare the final executable output for the same amount and token pair, including wallet gas where applicable. An Ophis base fee is not a substitute for an AMM's pool fee: a solver route can itself use that AMM and incur its liquidity costs. Improvement capture and hosted protocol fees also affect the result. A lower advertised base rate alone does not establish a saving over a direct swap.

WETH rebate calculation

The rebate calculation allocates 21.25% of collected WETH fees to eligible wallets in proportion to their 30-day volume weighted by tier. WETH payout processing requires reconciled accounting, sufficient funds and Safe approval. An estimate or cycle date is not proof of payment; executed payout transactions establish what was paid.

Tier	30-day volume	Weight
Bronze	$20,000+	10%
Silver	$50,000+	15%
Gold	$100,000+	25%
Palladium	$500,000+	35%
Platinum	$1,000,000+	50%

A wallet's share is its eligible 30-day volume × tier weight, divided by the sum of that value across every eligible wallet. For example, $100,000 of Gold volume has a weighted value of $25,000. If the total weighted value is $250,000, that wallet receives 10% of the pool: $1,000 equivalent from an illustrative $10,000 WETH pool. Actual amounts depend on collected WETH and all participants; this is not a promised payout.

Wallets below $20,000 of 30-day volume are unranked and do not share in the pool. Your current tier and progress to the next one are shown on the swap page. Rebates are separate from execution output. Neither a rebate nor positive surplus is guaranteed, and a tier weight is not a refund percentage of your own fees.

How it's collected

The fee uses CoW Protocol's partner-fee model. The Ophis swap app and SDK write the 1 bp base on every supported chain. On hosted chains they also write a pair-aware priceImprovementBps entry with a hard maxVolumeBps cap; operated chains in the standard schedule apply that second component in the backend instead to avoid duplication.

On the SDK-supported Ophis stacks (Optimism, Unichain, Robinhood Chain, Arc), the backend also enforces an anti-abuse minimum in backend order validation, rather than relying only on frontend metadata: it rejects an order to the Ophis fee recipient whose partner fee falls below 1 bp. This rejects declared sub-floor fee entries; absent fee metadata does not establish the same guarantee. It is not a Solidity minimum-fee invariant in the settlement contract. On CoW-hosted chains no sovereign floor is enforced, the same appData rate applies (validated by CoW's backend), and CoW's protocol fees (see the all-in table above) are charged by CoW on top.

For the protocol-level details, see CoW Protocol batch auctions.

note

The rebate pool is the WETH the fee Safe holds; fees collected in other tokens are not currently part of it. Want to earn on trades you refer? See the Affiliate program: share a code and earn a share of the verified base fee Ophis keeps on every trade your referrals route.