NEAR

Params

type serializedTransaction = string;

To execute transactions from NEAR, the parameter serializedTransaction must be provided. These data are available through the near-api-js library, and comprehensive usage is explained in the link and the example below.

Example

Consider the following example of connecting with a pre-deployed counter contract on the NEAR Testnet. The contract code is available on the repository.

You are required to have at least a certain amount of NEAR to execute a transaction that modifies the state of the contract. You can request faucet through the FAUCET tab in the wallet.

The code that follows sends a transaction that runs the contract's increment operation. The increment method employs the FunctionCall action type to add the counter value within the contract by the count value supplied as an input parameter.

Live Editor

function sendTransaction() { const CHAIN_NAME = 'near'; const [accounts, setAccounts] = React.useState(null); const [txHash, setTxHash] = React.useState(null); const getSerializedTransaction = async () => { try { const rpc = 'https://rpc.testnet.near.org'; const provider = new providers.JsonRpcProvider(rpc); const signerId = accounts.address; const publicKey = accounts.pubKey; const accessKey = await provider.query(`access_key/${signerId}/${publicKey}`, ''); const actions = [ transactions.functionCall( 'increment', // methodName { count: 5 }, // args new BN('30000000000000'), // 30 TGas new BN(0), ), ]; const recentBlockHash = utils.serialize.base_decode(accessKey.block_hash); // make transaction const transaction = transactions.createTransaction( signerId, // signerId utils.PublicKey.fromString(publicKey), //pubKey 'mycontract.myaccount8.testnet', // contract Id accessKey.nonce + 1, // nonce actions, // actions recentBlockHash, // recentBlockHash ); const bytes = transaction.encode(); return Buffer.from(bytes).toString('base64'); } catch (error) { /* error */ console.log(error); } }; async function handleGetAccount() { try { const accounts = await dapp.request(CHAIN_NAME, { method: 'dapp:accounts', }); setAccounts(accounts[CHAIN_NAME]); } catch (error) { alert(error.message); } } async function handleSendTransaction() { try { const serializedTransaction = await getSerializedTransaction(); const response = await dapp.request(CHAIN_NAME, { method: 'dapp:sendTransaction', params: [`${serializedTransaction}`], }); const txHash = response; setTxHash(txHash); } catch (error) { console.log(error); alert(`Error Message: ${error.message}\nError Code: ${error.code}`); } } return ( <> {accounts ? ( <> <Button onClick={handleSendTransaction} type="button"> Send a Transaction </Button> <ResultTooltip style={{ background: '#3B48DF' }}> <b>Accounts:</b> {accounts.address} </ResultTooltip> </> ) : ( <> <Button onClick={handleGetAccount} type="button"> Get Account </Button> <div>You have to get account first!</div> </> )} {txHash && ( <ResultTooltip style={{ background: '#F08080' }}> <b>Transaction Hash:</b> {txHash} </ResultTooltip> )} </> ); }

function sendTransaction() {
  const CHAIN_NAME = 'near';
  const [accounts, setAccounts] = React.useState(null);
  const [txHash, setTxHash] = React.useState(null);
  const getSerializedTransaction = async () => {
    try {
      const rpc = 'https://rpc.testnet.near.org';
      const provider = new providers.JsonRpcProvider(rpc);
      const signerId = accounts.address;
      const publicKey = accounts.pubKey;

      const accessKey = await provider.query(`access_key/${signerId}/${publicKey}`, '');

      const actions = [
        transactions.functionCall(
          'increment', // methodName
          { count: 5 }, // args
          new BN('30000000000000'), // 30 TGas
          new BN(0),
        ),
      ];
      const recentBlockHash = utils.serialize.base_decode(accessKey.block_hash);

      // make transaction
      const transaction = transactions.createTransaction(
        signerId, // signerId
        utils.PublicKey.fromString(publicKey), //pubKey
        'mycontract.myaccount8.testnet', // contract Id
        accessKey.nonce + 1, // nonce
        actions, // actions
        recentBlockHash, // recentBlockHash
      );
      const bytes = transaction.encode();

      return Buffer.from(bytes).toString('base64');
    } catch (error) {
      /* error */
      console.log(error);
    }
  };

  async function handleGetAccount() {
    try {
      const accounts = await dapp.request(CHAIN_NAME, {
        method: 'dapp:accounts',
      });

      setAccounts(accounts[CHAIN_NAME]);
    } catch (error) {
      alert(error.message);
    }
  }
  async function handleSendTransaction() {
    try {
      const serializedTransaction = await getSerializedTransaction();
      const response = await dapp.request(CHAIN_NAME, {
        method: 'dapp:sendTransaction',
        params: [`${serializedTransaction}`],
      });
      const txHash = response;

      setTxHash(txHash);
    } catch (error) {
      console.log(error);
      alert(`Error Message: ${error.message}\nError Code: ${error.code}`);
    }
  }

  return (
    <>
      {accounts ? (
        <>
          <Button onClick={handleSendTransaction} type="button">
            Send a Transaction
          </Button>
          <ResultTooltip style={{ background: '#3B48DF' }}>
            <b>Accounts:</b> {accounts.address}
          </ResultTooltip>
        </>
      ) : (
        <>
          <Button onClick={handleGetAccount} type="button">
            Get Account
          </Button>
          <div>You have to get account first!</div>
        </>
      )}
      {txHash && (
        <ResultTooltip style={{ background: '#F08080' }}>
          <b>Transaction Hash:</b> {txHash}
        </ResultTooltip>
      )}
    </>
  );
}

Result

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