Avalanche API Usage Example

import { Avalanche, Buffer } from 'avalanche';

import {
  PlatformVMAPI,
  KeyChain,
  UnsignedTx,
  Tx,
} from 'avalanche/dist/apis/platformvm';

import { PrivateKeyPrefix } from 'avalanche/dist/utils';

export async function signAndSubmitTx(
  hexEncodedTx: string,
  avalanche: Avalanche,
  privKey: string,
): Promise<string> {
  const pchain: PlatformVMAPI = avalanche.PChain();
  const pKeychain: KeyChain = pchain.keyChain();

  if (!privKey.startsWith(PrivateKeyPrefix)) {
    privKey = `${PrivateKeyPrefix}${privKey}`;
  }

  pKeychain.importKey(privKey);

  const unsignedTx: UnsignedTx = new UnsignedTx();
  unsignedTx.deserialize(hexToObject(hexEncodedTx));

  const signedTx: Tx = unsignedTx.sign(pKeychain);

  return pchain.issueTx(signedTx);
}

function hexToObject(hexString: string) {
  const buffer = Buffer.from(hexString, 'hex');
  const jsonString = buffer.toString('utf-8');
  return JSON.parse(jsonString);
}

const apiAddress = 'https://svc.blockdaemon.com/boss';

async function processTransaction(transactionType: string, requestOptions: any) {

    const request = {
      amount: '1000000000',
      delegator_address: 'P-fuji1ajsy7pf4jdd6zyhywzmvvvr54rs03j0hrqtm4g',
      validator_address: 'NodeID-3tKjUEqW9kqEZ3JYAC89BWttahsELRqpc',
    };

    requestOptions.body = JSON.stringify(request);

    const response = await fetch(`${apiAddress}/v1/avax/fuji/${transactionType}`, requestOptions);

    if (!response.ok) {
        throw new Error('Response from BOSS API was not ok: ' + await response.text());
    }

    const responseJson = await response.json();

    if (!responseJson.avax) {
        throw new Error('Response from BOSS API did not include avax field: ' + JSON.stringify(responseJson));
    }

    const avalanche = new Avalanche('api.avax-test.network', 443, 'https', 5);

    const pchain: PlatformVMAPI = avalanche.PChain();
    const pKeychain: KeyChain = pchain.keyChain();

    let privKey = process.env["PRIVATE_KEY"];
    if (!privKey) {
      throw new Error('No private key found in environment');
    }

    if (!privKey.startsWith(PrivateKeyPrefix)) {
      privKey = `${PrivateKeyPrefix}${privKey}`;
    }

    pKeychain.importKey(privKey);

    const unsignedTx: UnsignedTx = new UnsignedTx();
    unsignedTx.deserialize(hexToObject(responseJson.avax.unsigned_transaction));
    console.log(pKeychain.getAddressStrings());

    const signedTx: Tx = unsignedTx.sign(pKeychain);
    return pchain.issueTx(signedTx);
}

async function createStake() {
    return await processTransaction('stake-intents', {
        method: 'POST',
        headers: {
            'Content-Type': 'application/json',
            'Accept': 'application/json',
            'X-API-Key': process.env["BOSS_API_KEY"],
        },
    });
}

createStake()
    .then(() => process.exit(0))
    .catch(err => {
        console.error(err);
        process.exit(1);
    });