Bridge Aggregator
A router that quotes across multiple bridges and selects the best path by price, speed, or reliability.
Bridge aggregators (LI.FI/Jumper, Socket/Bungee, Rango) integrate with many underlying bridges and DEXs to route a cross-chain transfer along the optimal path. The user signs once; the aggregator picks the bridge. The trust model of the chosen bridge is what the user is actually exposed to, not the aggregator itself.
Practical Example & Calculation
Hypothetical scenario
Hypothetical numbers: a user wants to move 10,000 USDC from Arbitrum to Base. An aggregator returns two executable quotes with all values denominated in USDC. Route A uses an intent bridge: a 12 USDC bridge fee, 1 USDC source-chain gas estimate, no destination swap, and 9,987 USDC minimum received. Route B uses a liquidity bridge plus a destination swap: an 8 USDC bridge fee, 1 USDC source gas, 3 USDC destination execution cost, and an estimated 4 USDC price-impact loss. Route B therefore looks cheaper if someone compares only the labeled bridge fees, but that omits two route components. Both quotes are hypothetical and do not describe current production pricing.
Formula
Estimated net output = input amount − bridge fee − source gas − destination gas or execution cost − swap price impact − aggregator fee. Effective route cost percentage = (input amount − minimum received) ÷ input amount × 100.
Calculation
For Route A, 10,000 − 12 − 1 = 9,987 USDC, so total cost is 13 USDC and 13 ÷ 10,000 × 100 = 0.13%. For Route B, 10,000 − 8 − 1 − 3 − 4 = 9,984 USDC, so total cost is 16 USDC and 16 ÷ 10,000 × 100 = 0.16%. Route A delivers 3 USDC more despite displaying the higher bridge fee. If Route B’s interface shows an estimated output above its enforceable minimum, compare the minimum received rather than the optimistic estimate.
What the result means
Output is only one selection dimension. The aggregator should also expose the underlying bridge, estimated arrival time, token contract on Base, and recovery route for a delayed fill. A 0.03 percentage-point saving would not justify accepting an unknown wrapped asset or a materially weaker validator, oracle, or upgrade-key model. Conversely, a user making a small transfer may rationally favor speed and simplicity over a few cents. Quotes can expire as relayer inventory, gas, and pool balances change, so this calculation belongs to the specific quote timestamp. Before signing, verify the approval amount and spender, the destination token, slippage or minimum-output protection, and which contracts custody or forward funds. The aggregator finds and assembles a path; it does not erase the smart-contract and settlement assumptions of every bridge and swap used along that path.