# Advanced Usage

> Lifecycle tracking, custom wallets, and advanced features.

> For the complete documentation index, see [llms.txt](/llms.txt). Markdown versions of documentation pages are available by appending `.md` to the page URL.

Source: https://dev.flare.network/network/flare-tx-sdk/advanced-usage

## Transaction lifecycle tracking[​](#transaction-lifecycle-tracking "Direct link to Transaction lifecycle tracking")

Every transaction goes through a series of stages. The SDK allows you to register callbacks at each stage to inspect or intercept the process. This is useful for logging, UI updates, or offline signing workflows.

```
Unsigned   ↓ signSigned (before submission)   ↓ submitSubmitted (pending confirmation)   ↓ confirmConfirmed
```

### Example[​](#example "Direct link to Example")

```
// 1. Before Signaturenetwork.setBeforeTxSignatureCallback(async (data) => {  console.log("Transaction prepared for signing:", data.unsignedTxHex);  console.log("Transaction type:", data.txType);  // Return false to cancel  return true;});// 2. Before Submissionnetwork.setBeforeTxSubmissionCallback(async (data) => {  console.log("About to submit signed tx:", data.signedTxHex);  console.log("Transaction ID:", data.txId);  return true; // false = cancel});// 3. After Submissionnetwork.setAfterTxSubmissionCallback(async (data) => {  console.log(`Tx ${data.txId} submitted, awaiting confirmation...`);  return true;});// 4. After Confirmationnetwork.setAfterTxConfirmationCallback(async (data) => {  console.log(`Tx ${data.txId} confirmed with status: ${data.txStatus}`);});
```

## Custom wallets[​](#custom-wallets "Direct link to Custom wallets")

If you're integrating a bespoke signer (custody service, backend signer, or another SDK), implement the [`Wallet`](https://github.com/flare-foundation/flare-tx-sdk/blob/HEAD/src/wallet/index.ts) interface. Choose the C-Chain-only interface or dual-chain (C + P) depending on your needs.

Security

If implementing your own wallet, ensure private keys are never exposed; use secure signers where possible.

### Required Methods[​](#required-methods "Direct link to Required Methods")

info

C-Chain support is sufficient for most applications. See the full [Wallet](https://github.com/flare-foundation/flare-tx-sdk/blob/main/src/wallet/wallet.ts) interface.

Method

C-Chain Only

C + P Chain

`getCAddress(): Promise<string>`

✅

✅

`signCTransaction(tx: string): Promise<string>`

✅

✅

`signAndSubmitCTransaction(tx: string): Promise<string>`

✅

✅

`signDigest(digest: string): Promise<string>`

✅

✅

`getPublicKey(): Promise<string>`

\-

✅

`signPTransaction(tx: string): Promise<string>`

\-

✅

`signEthMessage(message: string): Promise<string>`

\-

✅

### Minimal ethers.js wrapper example[​](#minimal-ethersjs-wrapper-example "Direct link to Minimal ethers.js wrapper example")

This example (using ethers.js v6) shows the shape - adapt to your transport and security model. This assumes your signer supports `signTransaction`, `sendTransaction`, and `getAddress`.

```
import type { Wallet as SdkWallet } from "@flarenetwork/flare-tx-sdk";// ^ type path: see src/wallet/index.ts in the repoimport {  Signer,  Transaction,  getBytes,  type TransactionRequest,  type Provider,} from "ethers";export class EthersWallet implements SdkWallet {  constructor(private readonly signer: Signer) {}  async getCAddress(): Promise<string> {    return await this.signer.getAddress();  }  async signCTransaction(unsignedTxHex: string): Promise<string> {    // Parse the (unsigned) serialized tx into a Transaction object    const tx = Transaction.from(unsignedTxHex);    if (tx.signature) {      throw new Error(        "Expected unsigned transaction, but a signature was present.",      );    }    const request: TransactionRequest = {      to: tx.to ?? undefined,      data: tx.data ?? undefined,      value: tx.value ?? undefined,      gasLimit: tx.gasLimit ?? undefined,      maxFeePerGas: tx.maxFeePerGas ?? undefined,      maxPriorityFeePerGas: tx.maxPriorityFeePerGas ?? undefined,      nonce: tx.nonce,      chainId: tx.chainId,      type: tx.type,    };    return await this.signer.signTransaction(request);  }  async signAndSubmitCTransaction(unsignedTxHex: string): Promise<string> {    const rawSigned = await this.signCTransaction(unsignedTxHex);    const provider: Provider | null = this.signer.provider;    if (!provider) throw new Error("Signer has no provider for submission.");    const sent = await provider.sendTransaction(rawSigned);    await sent.wait(); // or omit if you want fire-and-forget    return sent.hash;  }  async signDigest(digestHex: string): Promise<string> {    // This signs the BYTES with the EIP-191 prefix.    return await this.signer.signMessage(getBytes(digestHex));  }  async signEthMessage(message: string): Promise<string> {    return await this.signer.signMessage(message);  }}
```

Need help or found a bug?

Open an issue on the [flare-foundation/flare-tx-sdk](https://github.com/flare-foundation/flare-tx-sdk) GitHub repository.