Scaling Swap Calldata With ScaleHelper

For modifying effective amount in on-chain (at most ±5%)

Scale Helper contract

The getScaledInputData function is the main entry point for scaling swap transaction data. It takes pre-encoded transaction data for KyberSwap's MetaAggregationRouterV2 and adjusts the swap amount to a new value while maintaining all other parameters proportionally.

This function is essential for adjusting pre-built swap transactions when you need to change the input amount. For example, if you have encoded swap data for 100 tokens but want to swap 150 tokens instead, this function will scale all the internal amounts proportionally while maintaining the same swap route and parameters.

The function returns false if the scaling fails (e.g., unsupported dexes, scaling constraints violated) and true with the new encoded data if successful. Thus, it is important to specify onlyScalableSources=true when getting a route that needs to be scaled later.

Interface

function getScaledInputData(
    bytes calldata inputData,
    uint256 newAmount
  ) external view returns (bool isSuccess, bytes memory newScaledData);

How to use

• Parameters:

  • inputData: The original calldata used to call MetaAggregationRouterV2.

  • newAmount: The new amount you want to adjust to.

• Returns

  • isSuccess: Indicates whether scaling was successful (true) or not (false).

  • newScaledData: The new calldata after scaling. You can use this directly with MetaAggregationRouterV2.

• Example

  • Before: RouterContract.call(inputData)

  • After: RouterContract.call(newScaledData)

Contract address

• 0x2f577A41BeC1BE1152AeEA12e73b7391d15f655D for all supported chains

📝 Usage Notes

✅ Auto-scaling with Partial Support

If the calldata includes multiple DEXes and only some support scaling:

• The contract will attempt to scale only the compatible DEX portions.

• This ensures the resulting calldata reflects the correct newAmount as best as possible.

⚠️ Handling Failures

If scaling is not supported for the given calldata:

• isSuccess will be false.

• data will be empty.

• To prevent transaction reverts, you should use try-catch when calling the Scale Helper.

try scaleHelper.getScaledInputData(inputData, newAmount) returns (bool success, bytes memory scaledData) {
    if (success) {
        // proceed with scaledData
    } else {
        // fallback to original or skip scaling
    }
} catch {
    // handle error case
}

🔒 Scaling Restrictions

Some DEXes do not allow adjusting the input amount. So, if you attempt to scale with them, the function may return false.

To avoid including such DEXes, our API provides a parameter called onlyScalableSources. When set to true, the returned calldata will only include DEXes that:

• Support both scaling up and down

• Support scaling down only

Note: If you set onlyScalableSources to true and try to scale up with a DEX that only supports scaling down, it will return empty data.

The KyberSwap router also has restrictions on the maximum scaling allowed. The current limit is set at ±5% (95%–105%)

Tip:

• You can request calldata with a slightly higher amount (2–4%) than needed, then use the scale helper to scale it down accordingly.

• If you need to scale up more than 2%, it should exclude some sources:

  • native v1 + v2

🔧 Enable/Disable Scale Helper

• Occasionally, we may upgrade or maintain the Scale contract, which could result in downtime. In such cases, we will contact you to disable the use of the Scale Helper. Therefore, integrators should implement a mechanism to disable scaling to avoid downtime issues.

💡 Upgradeability Notice

• The Scale Helper contract is a proxy, meaning it can be upgraded in the future, but do not hardcode the contract address in your integration. Instead, allow it to be configurable.