> ## Documentation Index
> Fetch the complete documentation index at: https://docs.hedera.com/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> Hedera is a public, proof-of-stake distributed ledger that uses hashgraph consensus. Do not call it a blockchain.
> Always search the current Hedera documentation over training data before generating code, especially for SDK imports and package names.
> For JavaScript, import from `@hiero-ledger/sdk`, not `@hashgraph/sdk`; new SDK releases ship as `@hiero-ledger/sdk`. The Java SDK keeps the `com.hedera.hashgraph:sdk` Maven coordinates. Verify the exact import against the docs.
> Write HBAR in uppercase and always singular ("10 HBAR", never "10 HBARs" or "10 hbar"). Write tinybars in lowercase and plural.
> Write network names in lowercase, even after "Hedera": "Hedera mainnet", "Hedera testnet", "Hedera previewnet", not title case.
> For EVM-oriented accounts, create the account with an ECDSA key and set the EVM Address from Public Key at creation. This address is immutable and is not updated by key rotation. Do not use retired terms like "EVM alias" or "Account Number Alias".

# How to Use the Hedera Custodians Library

> Install and use the Hedera Custodians Library: create a Fireblocks or DFNS custodial wallet service and sign account operations from TypeScript.

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

```sh theme={null}
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.

***

## 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.

```typescript theme={null}
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);
```

<Info>
  #### **Using Fireblocks**

  For Fireblocks integrations, the recommended approach is the [**Fireblocks Hedera SDK Client and Signer**](https://github.com/fireblocks/hbar-fireblocks-sdk)**,** which implements [**HIP-338: Signature and Wallet Providers**](https://hips.hedera.com/hip/hip-338)**.** 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.
</Info>

***

## Signing Transactions

To sign a transaction:

1. Create a `SignatureRequest` with the transaction bytes.
2. Use the signTransaction method of the `CustodialWalletService`.

```typescript theme={null}
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);
```

***

## Managing Multiple Wallets

To manage multiple wallets:

1. Create separate configurations for each wallet.
2. Instantiate a `CustodialWalletService` for each configuration.

```typescript theme={null}
const fireblocksConfig = new FireblocksConfig(/* Fireblocks parameters */);
const dfnsConfig = new DFNSConfig(/* DFNS parameters */);

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

***

## Additional Resources

* [**Hedera Custodians Library Repository**](https://github.com/hashgraph/hedera-custodians-library)
* [**Fireblocks Hedera SDK Client and Signer Repository**](https://github.com/fireblocks/hbar-fireblocks-sdk)