This does not refer to importing/exporting wallets within Particle Auth;
Particle Network's MPC-TSS accounts do not support importing/exporting
private keys.
This is specific to custom account connection with Particle Connect.
```kotlin Kotlin theme={null}
val account = connectAdapter.importWalletFromPrivateKey(privateKey)
val account = connectAdapter.importWalletFromMnemonic(mnemonic)
// Exportation
val privateKey = connectAdapter.exportWalletPrivateKey(address)
```
### Sign and Send Transaction
To initiate a transaction for signature and ultimately settlement on-chain, you'll need to use `connectAdapter.signAndSendTransaction` (for both EVM and Solana). This will return a popup to the adapter in question, prompting a signature from the end user. Once they confirm, the transaction will be immediately sent to the network.
`connectAdapter.signAndSendTransaction` takes the following parameters:
* `address` — The user address to target for initiating the transaction.
* `transaction` — A stringified transaction object, including fields such as `to`, `from`, `value`, `data`, and others.
* `callback` — A function to handle the transaction's return response.
| Field | Type | Description |
| :-------------- | :------------------ | :---------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `publicAddress` | `String` | For the connected public address, if `adapter` is `AuthCoreAdapter`, you can pass an empty string; for other wallet types, you need to pass a connected public address. |
| `transaction` | `String` | EVM transaction, expressed as a hexadecimal string, or a Solana transaction, expressed as a base58 string. |
| callback | TransactionCallback | A function to handle the transaction's return response. |
E.g.:
```kotlin Kotlin theme={null}
connectAdapter.signAndSendTransaction(address, transaction, callback)
adapter.signAndSendTransaction(publicAddress = "", transaction = "tx",
object : TransactionCallback {
override fun onTransaction(transactionId: String?) {
// Handle success
}
override fun onError(error: ConnectError) {
// Handle error
}
})
```
### Sign Transaction
`connectAdapter.signTransaction` is a **Solana-specific** method for signing a transaction without pushing it to the network. Specifically, this method requires the following parameters:
| Field | Type | Description |
| :-------------- | :----------- | :---------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `publicAddress` | `String` | For the connected public address, if `adapter` is `AuthCoreAdapter`, you can pass an empty string; for other wallet types, you need to pass a connected public address. |
| `transaction` | `String` | EVM transaction, expressed as a hexadecimal string, or a Solana transaction, expressed as a base58 string. |
| callback | SignCallback | A function to handle the transaction's return response. |
E.g.:
```kotlin Kotlin theme={null}
connectAdapter.signTransaction(address, transaction, callback)
// Alternatively, the plural form of this method, takes a list of transactions
connectAdapter.signAllTransactions(address, transactions, callback)
```
### Sign Message
To sign a basic UTF-8 message (string), you can use `connectAdapter.signMessage` to prompt the user for a signature alongside the message in question. `connectAdapter.signMessage` takes the following parameters:
| Field | Type | Description |
| :-------------- | :----------- | :---------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `publicAddress` | `String` | For the connected public address, if `adapter` is `AuthCoreAdapter`, you can pass an empty string; for other wallet types, you need to pass a connected public address. |
| `transaction` | `String` | EVM transaction, expressed as a hexadecimal string, or a Solana transaction, expressed as a base58 string. |
| callback | SignCallback | A function to handle the transaction's return response. |
E.g.:
```kotlin Kotlin theme={null}
connectAdapter.signMessage(address, message, callback)
```
### Sign Typed Data
Alternatively, **for EVM chains**, you can request that a user signs typed (structured) data rather than purely a raw string. To do this, you can use `connectAdapter.signTypedData` (equivalent to `eth_signTypedData`). This takes the following parameters:
| Field | Type | Description |
| :-------------- | :----------- | :---------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `publicAddress` | `String` | For the connected public address, if `adapter` is `AuthCoreAdapter`, you can pass an empty string; for other wallet types, you need to pass a connected public address. |
| `data` | `String` | the typed data to be signed; see the [Web (JavaScript/TypeScript)](/social-logins/auth/desktop-sdks/web) page for additional guidance. |
| callback | SignCallback | A function to handle the transaction's return response. |
* `address` — The user address to target for signature initiation.
* `data` — The typed data to be signed. For more details, refer to the [Web (JavaScript/TypeScript)](/social-logins/auth/desktop-sdks/web) documentation.
* `callback` — A function to handle the response after the signature process.
E.g.:
```kotlin Kotlin theme={null}
connectAdapter.signTypedData(address, data, callback)
```
### (Optional) Custom WalletConnect Project ID
```kotlin Kotlin theme={null}
//call before ParticleConnect.init
ParticleNetwork.setWalletConnectProjectId("Your WalletConnect Project ID, from https://cloud.walletconnect.com")
```
## Custom WalletConnect Adapter
There may be cases where the existing selection of adapters doesn't include a wallet you'd like to be featured within Particle Connect.
Creating a custom adapter (using **WalletConnect**) is simple. Doing so will require a structure **similar to the example below**, in which a custom **Coin98** adapter is made.
```xml XML theme={null}
