SignTransaction

SignAndSendTransaction is the simplest and most recommended method for sending a transaction. Backpack submits the transaction immediately after signing so it is safer for users and a simpler API for developers, rather than relying on the application to do so.

However, it is also possible for an app to request just the signature from Backpack. Once signed, an app can submit the transaction itself using the web3.js sendRawTransaction.

Base URL

https://backpack.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 session.

• nonce (required): A nonce used for encrypting the request, encoded in base58.

• redirect_link (required): The URI where Backpack should redirect the user upon completion. Please review Specifying Redirects for more details. URL-encoded.

• payload (required): An encrypted JSON string with the following fields:

  {
    "transaction": "...", // serialized transaction, base58 encoded
    "session": "...", // token received from connect-method
  }

  • transaction (required): The transaction that Backpack will sign is serialized and encoded in base58.

  • session (required): The session token received from the Connect method. Please see Handling Sessions for more details.

Returns

Approve

• nonce: A nonce used for encrypting the response, encoded in base58.

• data: An encrypted JSON string. Refer to Encryption to learn how apps can decrypt data using a shared secret. Encrypted bytes are encoded in base58.

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

  • transaction: The signed and serialized transaction that is encoded in base58. Backpack will not submit this transaction. An application can submit this transaction via the web3.js sendRawTransaction.

Reject

An errorCode and errorMessage as query parameters.

Please refer to Errors for a full list of possible error codes.

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