Contracts

Call or deploy contracts from your backend wallet to any EVM blockchain with one API call.

This request requires gas funds in the backend wallet.

const resp = await fetch(
  "<engine_url>/contract/<chain>/<contract_address>/write",
  {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      Authorization: "Bearer <access_token>",
      "x-backend-wallet-address": "<backend_wallet_address>",
    },
    body: JSON.stringify({
      functionName: "transferFrom",
      args: [
        "0x1946267d81Fb8aDeeEa28e6B98bcD446c8248473",
        "0x3EcDBF3B911d0e9052b64850693888b008e18373",
        "0",
      ],
    }),
  },
);
 
const { result } = await resp.json();
// queueId is a reference to the transaction queued by Engine.
console.log("Queue ID:", result.queueId);

function mintTo(address to) public

function mintTo(address to, uint256 quantity) public

{
	"functionName": "mintTo(address, uint256)",
	"args": ["0x4Ff9aa707AE1eAeb40E581DF2cf4e14AffcC553d", "3"]
}

See API reference

To send native tokens to a payable method (e.g. ETH on Ethereum), set txOverrides.value in the request body to POST /contract/<chain>/<contract_address>/write.

{
  functionName: "...",
  args: [ ... ],
  txOverrides: {
    value: 1000000000000000, // 0.001 ETH in wei
  }
}

To override the gas settings for your transaction, set txOverrides in the request body to any write transaction. Each of these fields are optional and will be estimated by Engine if omitted.

{
  functionName: "...",
  args: [ ... ],
  txOverrides: {
    // The limit of gas units to use for this transaction.
    gas: "530000",
    // The max fee (e.g. gas price) to use in wei.
    maxFeePerGas: "1000000000",
    // The max priority fee to use in wei.
    maxPriorityFeePerGas: "1000000000",
}

const resp = await fetch(
  "<engine_url>/contract/<chain>/<contract_address>/read?functionName=balanceOf&args=0x3EcDBF3B911d0e9052b64850693888b008e18373",
  {
    headers: {
      Authorization: "Bearer <access_token>",
    },
  },
);
 
const { result } = await resp.json();
console.log("ERC-20 balance:", result);

This request requires gas funds in the backend wallet.

const resp = await fetch(
  "<engine_url>/deploy/<chain>/prebuilts/nft-drop",
  {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      Authorization: "Bearer <access_token>",
      "x-backend-wallet-address": "<backend_wallet_address>",
    },
    body: JSON.stringify({
      contractMetadata: {
        name: "thirdweb Engine example",
        symbol: "eng",
        primary_sale_recipient:
          "0x3EcDBF3B911d0e9052b64850693888b008e18373",
      },
    }),
  },
);
 
const { result } = await resp.json();
// queueId is a reference to the transaction queued by Engine.
console.log("Queue ID:", result.queueId);