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Version: 0.7.0

Smart Contract Call Flow

Call an EVM smart contract from a Tezos X EVM dApp via the NAC gateway.

Example: Counter contract​

// increment()
await window.ethereum.request({
  method: 'eth_sendTransaction',
  params: [{
    to: '0x7b0e325FF8F70d21891A7494B5715C6dC3d08D7b',
    data: '0xd09de08a', // increment() selector
    gas: '0x186a0',
  }]
});

Function selectors (Counter)​

FunctionSelectorNotes
increment()0xd09de08a
decrement()0x2baeceb7
setNumber(uint256)0x3fb5c1cb
retrieve()0x2e64cec1Read — goes through eth_call, not the gateway

Only selectors on the relayer's curated allow-list can be sent via eth_sendTransaction; unknown selectors are rejected with UnknownSelectorError before any signing popup opens. See Selector resolution.

Sequence​

The hash returned to the dApp is a synthetic hash — the real kernel-synthesized EVM hash is resolved lazily. See EIP-1193 → synthetic hash.

ABI encoding​

// setNumber(42)
function encodeSetNumber(value) {
  const hex = value.toString(16).padStart(64, '0');
  return '0x3fb5c1cb' + hex;
}

await window.ethereum.request({
  method: 'eth_sendTransaction',
  params: [{
    to: '0x7b0e325FF8F70d21891A7494B5715C6dC3d08D7b',
    data: encodeSetNumber(42),
  }]
});

See also​