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

# SignTransaction

> Request Phantom to sign a single Solana transaction via deeplink and return the signature to your app.

Request Phantom to sign the prepared transaction and return the signature. After receiving the signature, your app can broadcast the transaction itself with [sendRawTransaction](https://solana-foundation.github.io/solana-web3.js/classes/Connection.html#sendRawTransaction) in web3.js, giving you full control over timing, batching, or custom error handling.

## Base URL

```
https://phantom.app/ul/v1/signTransaction
```

## Query string parameters

* `dapp_encryption_public_key` (required): The original encryption public key used from the app side for an existing [Connect](/phantom-deeplinks/provider-methods/connect) session.
* `nonce` (required): A nonce used for encrypting the request, encoded in base58.
* `redirect_link` (required): The URI where Phantom should redirect the user upon completion. For more details, see [Specify redirects](/phantom-deeplinks/specifying-redirects). URL-encoded.
* `payload` (required): An encrypted JSON string with the following fields:

  ```json theme={null}
  {
    "transaction": "...", // serialized transaction, base58 encoded
    "session": "...", // token received from connect-method
  }
  ```

  * `transaction` (required): The [transaction](https://solana-foundation.github.io/solana-web3.js/classes/Transaction.html) that Phantom will sign, serialized and encoded in base58.
  * `session` (required): The session token received from the [Connect](/phantom-deeplinks/provider-methods/connect) method. For more details, see [Handle sessions](/phantom-deeplinks/handling-sessions).

## Returns

### Approve

* `nonce`: A nonce used for encrypting the response, encoded in base58.
* `data`: An encrypted JSON string. Refer to [Encryption](/phantom-deeplinks/encryption) to learn how apps can decrypt `data` using a shared secret. Encrypted bytes are encoded in base58.

  ```json theme={null}
  // content of decrypted `data`-parameter
  {
      transaction: "...", // signed serialized transaction, base58 encoded
  }
  ```

  * `transaction`: The signed, serialized transaction that is base58 encoded. Phantom will not submit this transaction. An application can submit this transaction itself using `sendRawTransaction` in [web3.js](https://solana-foundation.github.io/solana-web3.js/classes/Connection.html#sendRawTransaction).

### Reject

An `errorCode` and `errorMessage` as query parameters. For a full list of possible error codes, see [Errors](/solana/errors).

```
{
  "errorCode": "...",
  "errorMessage": "..."
}
```

## Example

Refer to the [signTransaction](https://github.com/phantom-labs/deep-link-demo-app/blob/20f19f2154e98699f0d5a6b28bc4bb3d5acbcefd/App.tsx#L262) method implemented in our React Native demo application.