Connext vs Across: A Technical Breakdown of Relayer Costs and Fee Models

Direct cost model: Users pay gas fees for the relayer's work on the destination chain, plus a small protocol fee. This creates predictable, transparent pricing for integrators. The relayer is a permissionless role, competing on fees and speed. Best for: Protocols that require stable, auditable cost structures and want to avoid subsidizing user transactions.

Indirect cost model: Relayer costs are paid from the liquidity pool's yield, not directly by the user. Users see a single, often lower, 'bridge fee' quote. This model relies on capital efficiency of the pool to cover costs. Best for: Applications prioritizing the simplest user experience where hiding gas complexity is a key feature.

Fixed protocol fee + variable gas: As an integrator, you can calculate your cost basis precisely—it's the destination chain gas cost. There's no dependency on pool profitability. This aligns with enterprise-grade financial planning and is similar to models used by LI.FI and Socket. Key Metric: Fee breakdowns are explicit in the API response.

Single, abstracted fee quote: Users don't need destination chain gas tokens. The economic complexity is absorbed by the protocol's liquidity system (UMA's optimistic oracle, LP rewards). This reduces friction but ties long-term viability to sustainable pool yields. Key Metric: A leading choice for dApps like Polymarket and Perpetual Protocol where UX is paramount.

No active relayer role: Connext uses a permissionless network of routers that compete on price. As a relayer, you don't need to monitor mempools or race to submit transactions, reducing operational complexity and engineering costs.

Clear revenue model: Routers earn fees by providing liquidity and setting their own spreads. Fees are taken upfront from the bridging amount, providing predictable, immediate yield rather than relying on future reimbursement.

Full gas reimbursement: Relayers ("fillers") are repaid for all gas costs on the destination chain, plus a premium. This model can yield higher net margins on high-volume routes, especially when optimizing for speed and winning the filler race.

First-to-fill wins: The fastest relayer to fulfill a request captures the entire fee. This creates a high-performance, competitive environment ideal for sophisticated operators with advanced mempool monitoring and transaction bundling tools.

Liquidity is king: Router profitability is tightly coupled to capital allocation efficiency. You must actively manage liquidity across chains and asset pools to maximize utilization, which adds strategic complexity and risk.

High execution risk: Relayers must front gas on the destination chain and compete in real-time. Failed transactions or network congestion directly eat into profits. This requires robust infrastructure and constant monitoring.

Fixed fee model: Relayers earn a flat 0.05% fee on transfer volume, providing predictable revenue streams. This simplicity matters for professional relayers and DAOs managing operational budgets, as it eliminates gas price volatility from their core earnings calculation.

No capital lockup: Relayers do not need to post bonded capital to facilitate transfers. This matters for smaller operators or new entrants who want to participate in the network without significant upfront capital commitment, lowering the barrier to becoming a relayer.

Capital efficiency rewards: Relayer profitability is driven by a real-time Dutch auction where they compete to fill transfers at the best rate. This matters for sophisticated, high-capital relayers who can optimize for speed and gas arbitrage, potentially earning fees above a standard baseline.

Gas cost coverage: The protocol's liquidity pool (UMA's Optimistic Oracle) reimburses relayers for on-chain gas costs on the destination chain. This matters for mitigating execution risk, as relayers are protected from sudden gas spikes on chains like Ethereum Mainnet, making operations more sustainable.

Gas cost exposure: Relayers pay gas upfront and are only reimbursed via the flat fee. In periods of high network congestion (e.g., Ethereum during a meme coin frenzy), transaction costs can exceed the fixed fee, leading to temporary losses or requiring sophisticated gas management.

Bonding requirement & complexity: Relayers must bond capital (WETH) and actively manage bids in a fast-paced auction. This matters as a barrier to entry and requires continuous monitoring and optimization, favoring large, automated operators over smaller participants.