Kotlin SDK send transactions - Polygon Developer Docs

sendTransaction and callContract are two input forms for the same lifecycle. Both require an active selected wallet and a supported Network.

The SDK prepares the request with OMS.
The preparation response either marks it sponsored or supplies fee options.
The SDK executes the prepared transaction with the applicable fee selection.
By default, the SDK polls until status resolves or the polling timeout expires.

Send native value

Values are non-negative raw base-unit integers. Use parseUnits to convert a display amount.

import technology.polygon.omswallet.Network
import technology.polygon.omswallet.utils.parseUnits

val result = omsWallet.wallet.sendTransaction(
    network = Network.AMOY,
    to = "0x1111111111111111111111111111111111111111",
    value = parseUnits("0.01", 18),
)

println("OMS transaction: ${result.txnId}")
println("Status: ${result.status}")
println("Hash: ${result.txnHash}")

parseUnits rounds fractional precision beyond decimals to the nearest base unit and requires a non-negative decimal count.

Send encoded calldata

Use the request overload when you already have calldata or need to set the transaction mode:

import technology.polygon.omswallet.Network
import technology.polygon.omswallet.models.SendTransactionRequest
import java.math.BigInteger

val result = omsWallet.wallet.sendTransaction(
    network = Network.AMOY,
    request = SendTransactionRequest(
        to = "0x2222222222222222222222222222222222222222",
        value = BigInteger.ZERO,
        data = "0x1234",
    ),
)

SendTransactionRequest.mode defaults to TransactionMode.Relayer. This mode is an execution input; it does not by itself promise sponsorship.

Call a contract by method and arguments

Use callContract when you have an ABI method signature and argument values rather than encoded calldata:

import kotlinx.serialization.json.JsonPrimitive
import technology.polygon.omswallet.Network
import technology.polygon.omswallet.models.AbiArg
import technology.polygon.omswallet.utils.parseUnits

val result = omsWallet.wallet.callContract(
    network = Network.AMOY,
    contract = "0x2222222222222222222222222222222222222222",
    method = "transfer(address,uint256)",
    args = listOf(
        AbiArg(
            type = "address",
            value = JsonPrimitive("0x1111111111111111111111111111111111111111"),
        ),
        AbiArg(
            type = "uint256",
            value = JsonPrimitive(parseUnits("1", 6).toString()),
        ),
    ),
)

The call is state-changing and follows the same prepare, fee, execute, and wait steps as sendTransaction.

Resolve sponsorship and fees

Testnet transaction fees are sponsored. On mainnet, OMS reports whether each prepared transaction is sponsored or requires a fee option. When the response is sponsored, the SDK executes without a fee selection and does not call your selector. For an unsponsored response:

No selector: the SDK submits the first returned fee option.
FeeOptionSelector.firstAvailable: the SDK chooses the first option whose known raw balance covers its quoted fee.
Custom selector: your callback returns a FeeOptionSelection from the available options.
No fee options, or a selector returning null: the SDK fails before execution.

import technology.polygon.omswallet.Network
import technology.polygon.omswallet.models.FeeOptionSelector
import technology.polygon.omswallet.utils.parseUnits

val result = omsWallet.wallet.sendTransaction(
    network = Network.POLYGON,
    to = "0x1111111111111111111111111111111111111111",
    value = parseUnits("0", 18),
    selectFeeOption = FeeOptionSelector.firstAvailable,
)

A custom selector receives FeeOptionWithBalance values:

import technology.polygon.omswallet.Network
import technology.polygon.omswallet.models.FeeOptionSelector
import technology.polygon.omswallet.utils.parseUnits

val result = omsWallet.wallet.sendTransaction(
    network = Network.POLYGON,
    to = "0x1111111111111111111111111111111111111111",
    value = parseUnits("0", 18),
    selectFeeOption = FeeOptionSelector { options ->
        options.firstOrNull {
            it.feeOption.token.symbol == "USDC"
        }?.selection
    },
)

Balance enrichment is best effort. The SDK asks the indexer for matching balances, but selector items can have null balance, available, availableRaw, or decimals when data is unavailable or the enrichment request fails. firstAvailable only selects an option when availableRaw is present and sufficient. It does not make an independent balance request or guarantee that execution will accept the fee.

Understand the returned status

SendTransactionResponse contains:

Field	Meaning
`txnId`	OMS transaction ID used for later status lookup
`status`	Latest OMS status, such as `Quoted`, `Pending`, `Executed`, or `Failed`
`txnHash`	Onchain hash when OMS has returned one
`statusResolution`	Whether waiting was skipped, resolved, or timed out

With the default waitForStatus = true, the SDK polls immediately after execution. It sets statusResolution = Resolved when status becomes Executed or Failed, or when OMS returns a nonblank transaction hash. A resolved response can therefore still report Pending when its hash is already available. If the timeout expires first, the response uses TimedOut and preserves the latest status and any hash. Timeout does not mean failure. Continue with getTransactionStatus(txnId). Set waitForStatus = false to return directly after execute:

import technology.polygon.omswallet.Network
import technology.polygon.omswallet.models.TransactionStatusResolution
import technology.polygon.omswallet.utils.parseUnits

val submitted = omsWallet.wallet.sendTransaction(
    network = Network.AMOY,
    to = "0x1111111111111111111111111111111111111111",
    value = parseUnits("0", 18),
    waitForStatus = false,
)

check(submitted.statusResolution == TransactionStatusResolution.NotRequested)
val current = omsWallet.wallet.getTransactionStatus(submitted.txnId)

An immediate response intentionally has txnHash = null; fetch status to obtain a later hash. getTransactionStatus returns the current status and nullable txnHash but does not add a statusResolution value. To tune waiting, pass TransactionStatusPollingOptions. Its defaults are fastPollCount = 5, fastPollIntervalMillis = 400, pollIntervalMillis = 2_000, and timeoutMillis = 60_000.

Handle interruption and uncertain execution

Coroutine cancellation stops the local SDK call or status polling. It is not an onchain cancellation and does not cancel a transaction that OMS may already have accepted for execution. Use waitForStatus = false when you need the SDK to return after execute instead of canceling a waiting coroutine. When execute fails before the SDK can confirm submission, it throws OMSWalletTransactionException with code = TransactionExecutionUnconfirmed and the prepared txnId. Do not automatically submit the write again because the first attempt may have reached OMS. When post-submit status polling fails, the exception uses TransactionStatusLookupFailed, includes txnId, and is retryable through getTransactionStatus.

​Send native value

​Send encoded calldata

​Call a contract by method and arguments

​Resolve sponsorship and fees

​Understand the returned status

​Handle interruption and uncertain execution