If a multi-hop bridge route has only partly executed, check which hop received funds and how much before deciding whether the transfer is complete. A partial fill means an execution has delivered less than the intended amount; it does not, by itself, say whether the remainder is still available, retrying, refunded, or stuck. That depends on the bridge and swap contracts involved.
When comparing routes, the Bungee Bridge can help you find paths across bridges and decentralized exchanges between EVM networks and layer 2 chains. A route may contain multiple transactions and asynchronous cross-chain settlements, so route completion is a sequence of states rather than one atomic event.
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What does a partial fill mean in a multi-hop route?
A partial fill is progress against an intended amount, not proof that every step in the route has finished. Some protocols let a solver or liquidity source execute only part of an order; other bridge calls either succeed for the amount submitted or revert, while later hops can still be pending or fail.
Track each hop’s input and output separately. For a route from Arbitrum through an intermediate chain to Base, the first bridge might deliver 850 of an intended 1,000 USDC while the remaining 150 is still processing or subject to a protocol-specific refund. The next hop can only use the amount actually delivered, less any swap or bridge deductions.
How does the amount change from hop to hop?
Each hop consumes its own input amount and applies its own exchange rate, fees, and minimum-output condition. For a swap leg, the executed output must satisfy that leg’s amountOutMin (or equivalent); a slippage tolerance is commonly expressed in basis points, where 100 bps equals 1%. A bridge transfer may instead have a fixed message amount, a fillable order amount, or its own completion and refund rules.
For example, suppose an illustrative 1,000 USDC route splits into two first-hop fills: 600 and 400. If one completes and the other delivers only 250, the next hop has 850 available in total only if both outputs are the same asset on the same chain and can be combined; otherwise, the 600 and 250 remain separate route legs. A downstream quote based on all 1,000 is stale, and its minimum output may no longer be achievable with 850.
There is no universal partial-fill percentage or retry interval: those are set by the route’s contracts, liquidity source, and transaction lifecycle. Slippage settings around 0.1–0.5% can suit deep, stable markets; volatile or thin pools may need more, but a wider tolerance also permits a worse execution price. A larger tolerance does not make a bridge message complete or recover the unfilled balance.
Which checks tell you whether the route is complete?
Use four checks, in order: confirm the source transaction and amount spent; identify the destination transaction or bridge message for each hop; compare actual received amounts with the next hop’s required input and minimum output; then verify that the final asset arrived on the destination chain. A source-chain confirmation alone establishes only that the source step ran, not that every cross-chain step settled.
The difficult edge case is a route that partially progresses but cannot continue: the delivered amount may fall below a downstream protocol’s minimum size, or the remaining amount may be too small to cover that hop’s fixed costs. Before retrying, check whether the remainder is still escrowed, independently claimable, refundable, or already included in a pending message; sending a fresh route for the original amount can duplicate funds or leave the first execution unresolved.
For your current transfer, record the transaction hash and the actual token amount at the last confirmed hop, then compare that amount with the next hop’s required input and minimum output. Treat the route as complete only when the intended destination asset is confirmed, or follow that bridge’s documented recovery path for the specific remainder.