eth_sendTransaction

Requests the wallet to create and send a transaction. After the user confirms in UKey Wallet, the Provider will broadcast the transaction to the current network and return the transaction hash.

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Inputs

Pass an array whose first item is the transaction object:

Field	Variant	Need	Remarks
from	string	yes	Authorized sender address
to	string	no	Recipient address; leave empty for contract deployment
value	string	no	Transfer amount in wei, encoded as hex
data	string	no	Call payload or deployment bytecode
gas	string	no	Gas limit encoded as hex
gasPrice	string	no	Legacy gas price
maxFeePerGas	string	no	EIP-1559 max fee cap
maxPriorityFeePerGas	string	no	EIP-1559 priority fee cap
nonce	string	no	Transaction nonce; usually let the wallet fill this

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return value

string - ​​Transaction hash, 32-byte hex string.

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Demo

Send ETH

const txHash = await window.$ukey.ethereum.request({
  method: "eth_sendTransaction",
  requestParams: [
    {
      from: "0x1a2b3c4d5e6f708192a3b4c5d6e7f8091a2b3c4d",
      to: "0x4b6d8f0123456789abcdef0123456789abcdef01",
      value: "0x2386f26fc10000", // sample ETH amount, in wei
    },
  ],
});

console.log("Tx hash:", txHash);

Call contract method

const txHash = await window.$ukey.ethereum.request({
  method: "eth_sendTransaction",
  requestParams: [
    {
      from: "0x1a2b3c4d5e6f708192a3b4c5d6e7f8091a2b3c4d",
      to: "0x2b4d6f8091a3c5e7f9b1d3f507192b4d6f8091a3",
      data: "0xa9059cbb...", // Note: Encoded function call
      gas: "0x5208",
    },
  ],
});

EIP-1559 Transaction

const txHash = await window.$ukey.ethereum.request({
  method: "eth_sendTransaction",
  requestParams: [
    {
      from: "0x1a2b3c4d5e6f708192a3b4c5d6e7f8091a2b3c4d",
      to: "0xc4d2e1f0a9876543210fedcba9876543210abcde",
      value: "0x2386f26fc10000",
      maxFeePerGas: "0x1dcd65000", // fee cap example
      maxPriorityFeePerGas: "0x77359400", // priority fee example
    },
  ],
});

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error code

Code	Message	Details
4001	User rejected the request	Transaction approval was rejected by the user
-32000	Insufficient funds	Insufficient balance
-32602	Parameters failed validation	Transaction inputs are invalid

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illustrate

• All numeric fields should be hex strings starting with 0x.
• If gas is not provided, the wallet will attempt to estimate it automatically.
• For networks that support EIP-1559, use maxFeePerGas and maxPriorityFeePerGas.
• from must be a currently authorized account, otherwise the request will fail.
• After the transaction is broadcast and still needs to wait for on-chain confirmation, please use RPC or a block explorer to track the hash status.