How to Use the Hedera Custodians Library

To install the Hedera Custodians Integration package from NPM, run the following command in your terminal:

npm install @hashgraph/hedera-custodians-integration

This command will install the Hedera Custodians Library along with all its necessary dependencies. Ensure you are in your project’s root directory or the appropriate subdirectory where you wish to add the library.

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Creating a Service

To create a custodial wallet service:

1. Choose the appropriate configuration (FireblocksConfig or DFNSConfig).

2. Instantiate the configuration with the required parameters.

3. Create a CustodialWalletService instance using the configuration.

import { CustodialWalletService, FireblocksConfig } from '@hashgraph/hedera-custodians-integration';

const config = new FireblocksConfig(
  FIREBLOCKS_API_KEY,
  FIREBLOCKS_API_SECRET_KEY,
  FIREBLOCKS_BASE_URL,
  FIREBLOCKS_VAULT_ACCOUNT_ID,
  FIREBLOCKS_ASSET_ID
);

const service = new CustodialWalletService(config);

Using Fireblocks

For Fireblocks integrations, the recommended approach is the Fireblocks Hedera SDK Client and Signer, which implements HIP-338: Signature and Wallet Providers. It includes complete examples, such as handling multiple nodes with maxNumberOfPayloadsPerTransaction and multi-signer flows.

You can still use this library’s FireblocksConfig with CustodialWalletService if you need a factory/strategy abstraction, but the official client/signer is the recommended route for new builds.

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Signing Transactions

To sign a transaction:

1. Create a SignatureRequest with the transaction bytes.

2. Use the signTransaction method of the CustodialWalletService.

import { SignatureRequest } from '@hashgraph/hedera-custodians-integration';

const transactionBytes = new Uint8Array([/* your transaction bytes */]);
const request = new SignatureRequest(transactionBytes);

const signature = await service.signTransaction(request);

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Managing Multiple Wallets

To manage multiple wallets:

1. Create separate configurations for each wallet.

2. Instantiate a CustodialWalletService for each configuration.

const fireblocksConfig = new FireblocksConfig(/* Fireblocks parameters */);
const dfnsConfig = new DFNSConfig(/* DFNS parameters */);

const fireblocksService = new CustodialWalletService(fireblocksConfig);
const dfnsService = new CustodialWalletService(dfnsConfig);

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Additional Resources

• Hedera Custodians Library Repository

• Fireblocks Hedera SDK Client and Signer Repository