signAndSend()

Use agent.signAndSend() to sign and broadcast blockchain transactions from your agent's wallet. Supports both Ethereum (EVM) and Solana networks. The transaction is signed by the agent's session wallet, broadcast to the network, and returns a transaction hash for tracking. Include an optional message parameter to help with debugging and observability in the Circuit UI.

Signature

agent.signAndSend(
  request: {
    network: string;
    message?: string;
    request: object; // Structure varies based on EVM or Solana
  }
): Promise<SignAndSendResponse>

Parameters

Param	Type	Description
request	object	Transaction configuration object
request.network	string	Network type: 'ethereum:{chainId}' | 'solana'
request.message?	string	Optional description for observability
request.request	object	Transaction details (see below)

Ethereum Transactions

When request.network is 'ethereum:{chainId}'

( request.request )

Property	Type	Description
toAddress	0x${string}	Recipient address
data	0x${string}	Transaction calldata (use "0x" for simple transfers)
value	string	ETH amount in wei (use "0" for no ETH)

Solana Transactions

When request.network is 'solana'

( request.request )

Param	Type	Description
hexTransaction	string	Serialized transaction in hex format

Returns

• Promise<SignAndSendResponse>

type SignAndSendResponse = {
  success: boolean;
  data?: { // Only present on success
    internalTransactionId: number;
    txHash: string;
    transactionUrl?: string;
  };
  error?: string;
  errorMessage?: string;
  errorDetails?: object;
}

Examples

EVM (native ETH transfer)

const result = await agent.signAndSend({
  network: "ethereum:1",
  request: {
    toAddress: "0x742d35cc6634C0532925a3b8D65e95f32B6b5582",
    data: "0x",
    value: "1000000000000000000" // 1 ETH in wei
  },
  message: "Sending 1 ETH"
});

if (result.success && result.data) {
  await agent.log(`Sent! TX: ${result.data.txHash}`);
}

EVM (contract interaction)

const result = await agent.signAndSend({
  network: "ethereum:42161", // Arbitrum
  request: {
    toAddress: "0xTokenContract...",
    data: "0xa9059cbb...", // encoded transfer() call
    value: "0"
  },
  message: "Token transfer"
});

if (result.success && result.data) {
  await agent.log(`Contract call successful: ${result.data.transactionUrl}`);
}

Solana

const result = await agent.signAndSend({
  network: "solana",
  request: {
    hexTransaction: "010001030a0b..." // serialized VersionedTransaction
  },
  message: "Solana swap"
});

if (result.success && result.data) {
  await agent.log(`Solana TX: ${result.data.txHash}`);
}

Common Errors

Error	Cause	Solution
"Transaction failed"	Insufficient balance for value or gas	Check currentPositions before sending
"Invalid address"	Malformed toAddress	Validate address format (0x... for EVM)
"Invalid data"	Malformed calldata	Ensure data is valid hex (use "0x" for simple transfers)
"Network error"	RPC unavailable	Retry or check network status