sign_and_send()

Use agent.sign_and_send() 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.sign_and_send(
    request: {
        network: str,
        message: str | None,
        request: dict  # Structure varies based on EVM or Solana
    }
) -> SignAndSendResponse

Parameters

Param	Type	Description
request	dict	Transaction configuration object
request.network	str	Network type: 'ethereum:{chainId}' | 'solana'
request.message	str | None	Optional description for observability
request.request	dict	Transaction details (see below)

Ethereum Transactions

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

( request.request )

Property	Type	Description
to_address	str	Recipient address
data	str	Transaction calldata (use "0x" for simple transfers)
value	str	ETH amount in wei (use "0" for no ETH)
gas	int | None	Gas limit for the transaction
max_fee_per_gas	str | None	Maximum fee per gas in wei
max_priority_fee_per_gas	str | None	Maximum priority fee per gas in wei (tip)
nonce	int | None	Transaction nonce (for custom ordering)
enforce_transaction_success	bool | None	Ignore failed transaction simulations

Solana Transactions

When request.network is 'solana'

( request.request )

Param	Type	Description
hexTransaction	str	Serialized transaction in hex format

Returns

• SignAndSendResponse

class SignAndSendResponse:
    success: bool
    data: { # Only present on success
        internal_transaction_id: int,
        tx_hash: str,
        transaction_url: str | None
    } | None
    error: str | None
    error_message: str | None
    error_details: dict | None

Examples

EVM (native ETH transfer)

response = agent.sign_and_send({
    "network": "ethereum:1",
    "request": {
        "to_address": "0x742d35cc6634C0532925a3b8D65e95f32B6b5582",
        "data": "0x",
        "value": "1000000000000000000"  # 1 ETH in wei
    },
    "message": "Sending 1 ETH"
})

if response.success and response.data:
    agent.log(f"Sent! TX: {response.data.tx_hash}")
    if response.data.transaction_url:
        agent.log(f"View: {response.data.transaction_url}")
else:
    agent.log(f"Failed: {response.error_message}", error=True)

EVM (contract interaction)

response = agent.sign_and_send({
    "network": "ethereum:42161",  # Arbitrum
    "request": {
        "to_address": "0xTokenContract...",
        "data": "0xa9059cbb...",  # encoded transfer() call
        "value": "0"
    },
    "message": "Token transfer"
})

if response.success and response.data:
    agent.log(f"Contract call successful: {response.data.transaction_url}")

Solana

response = agent.sign_and_send({
    "network": "solana",
    "request": {
        "hex_transaction": "010001030a0b..."  # serialized VersionedTransaction
    },
    "message": "Solana swap"
})

if response.success and response.data:
    agent.log(f"Solana TX: {response.data.tx_hash}")

Common Errors

Error	Cause	Solution
"Transaction failed"	Insufficient balance for value or gas	Check currentPositions before sending
"Invalid address"	Malformed to_address	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