Example:
https://polygonscan.com/tx/0xf3a7a37d7a12950e29d477349562bc2ab09e3cac140c1567f39ae1e3614fe01e
The error here is a slippage error. Due to high slippage on the exchange rate, the returned amount would be lower than the defined slippage. For that reason, the tx was rejected by the DEX.
Detailed Analysis
- The Arbitrum transaction was a sponsored user operation (sponsoredCallV2) to an
EntryPoint contract.
Key observations on Tenderly and Arbiscan:
Logs: The transaction logs on Tenderly show an account being deployed
on-chain, followed by a revert. The critical log is a UserOperationRevertReason
with revert data decoding to "Return amount is not enough". This matches LI.FI’s
known slippage error: the DEX swap returned less than the minimum allowed, so
it reverted. - Call Stack & Behavior: The flow was likely: (1) deploy a new smart contract
wallet via the EntryPoint, (2) immediately attempt a swap or token transfer, (3)
receive too little output and hit a slippage check. Because of the revert, the user
operation’s UserOperationEvent shows success: False, and the entire operation
failed in the DEX call step.
3. Gas Usage: Gas was not the issue – the transaction had a huge limit (50M) but
only ~1.16M was used (2.31%).The gas price was extremely low, indicating it
was sponsored. No out-of-gas or exceeding limit occurred.
4. Root Cause: The failure is a slippage error. LI.FI’s docs explain that “Return
amount is not enough” means the price moved unfavorably and the swap output
fell below the user’s minimum expectation because of the tight slippage
tolerance. Because of this, the DEX contract reverted the trade.
Resolution: To resolve, the user should increase their slippage tolerance or pick
a different route.