Custom Gas Fee Control added to Create transaction requests API

The Create transaction requests API (/wallet/send-many-transaction) now supports the following optional parameters for gas fee estimation when processing a transaction for EVM chains. This improves transaction confirmation rate and prioritises block inclusion speed over default cost savings by proving more control over gas fee price estimates.

Object/ Parameter	Description	Type	Accepted Values
feeLevel	The fee level setting used to pay gas fee when processing a transaction for EVM chains. It is configured based on the blockchain network’s traffic.	String	market, custom, slow, aggressive
evmCustomFee	User defined custom fee per transaction. Applicable for EVM chains when feeLevel is custom.	String	-
evmCustomFee.maxPriorityFeePerGas	Enter fee value in Wei.	String	Positive number, example: “3000000000”
evmCustomFee.maxFeePerGas	The maximum fee (Wei) per unit of gas in a transaction.	String	Positive number, example: “20000000000”

📘
Note

maxPriorityFeePerGas cannot be greater than maxFeePerGas.

The parameter values must be a positive number.

Refer to the Retrieve estimated gas fees and rates API (/get-approx-fees) to get the latest fee rates.

Transaction Lifecycle Timestamp and Metrics added to Transaction API References

The transaction APIs as part of the Express SDK now return additional timeline logs for withdrawal and deposit transactions. The system-level alerts provide insight into the timestamps of a transaction lifecycle to help users keep track of the real-time transaction progress.
The following API references return the timestamps and metrics objects when a transaction is processed in 200 OK responses.

The following table explains the object values:

Field	Description	Data Type	Applicable Transaction
`timestamps.initiatedAt`	Indicates the time when a transaction is initiated.	String	Send transactions
`timestamps.signedAt`	Indicates the time when a transaction is fully approved, i.e., final signature.	String	Send transactions
`timestamps.broadcastedAt`	Indicates the time when a transaction is broadcasted on the network.	String	Send transactions
`timestamps.blockTimestamp`	Indicates the time of a transaction’s on-chain block confirmation.	String	Send transactions
`timestamps.completedAt`	Indicates the time when a transaction is fully processed by the Liminal system.	String	Send and Receive transactions
`timestamps.detectedAt`	Indicates the time when a transaction is detected by the Liminal system.	String	Send and Receive transactions
`timestamps.webhookFirstAttemptAt`	Indicates the time when the final webhook is attempted for the first time.	String	Send and Receive transactions
`timestamps.webhookDeliveredAt`	Indicates the time when the final webhook is attempted for the first time.	String	Send and Receive transactions
`metrics.timeToConfirmInSec`	Indicates the time (seconds) taken to confirm a transaction on chain.	String	Send transactions
`metrics.detectionLatencyInSec`	Indicates the time (seconds) between on-chain confirmation and system detection.	String	Receive and Internal transactions
`metrics.totalProcessingTimeInSec`	Indicates the total time taken (seconds) to process the transaction from when it was initiated to on-chain confirmation. Send transaction processes the time from when transaction is initated to completed (completedAt - initiatedAt). Receive transaction reports trsnaction from it is completed (completedAt - blockTimestamp)	String	Send and Receive transactions

Response example of a Send transaction:

{
  "timestamps": {
    "initiatedAt": "2026-06-01T10:00:00.000Z",
    "signedAt": "2026-06-01T10:00:05.000Z",
    "broadcastedAt": "2026-06-01T10:00:06.000Z",
    "blockTimestamp": "2026-06-01T10:00:18.000Z",
    "completedAt": "2026-06-01T10:00:18.500Z",
    "detectedAt": "2026-06-01T10:00:01.000Z",
    "webhookFirstAttemptAt": "2026-06-01T10:00:19.000Z",
    "webhookDeliveredAt": "2026-06-01T10:00:19.200Z"
  },
  "metrics": {
    "timeToConfirmInSec": "10",
    "detectionLatencyInSec": null,
    "totalProcessingTimeInSec": "15"
  }
}