How to sign RAW transactions?

This page describes how to sign raw transactions and submit them yourself to the blockchain.

The Venly Wallet-API takes care of the complete blockchain management to execute transactions (signing, submitting, and follow-up).

We advise only using the regular transaction API (POST /transactions/execute) to perform blockchain operations.

Only use the below-described functionality if you know how blockchain technology works.

Context

In some cases, you may want to submit transactions yourself to the blockchain. For example, you may want to submit transactions through your own blockchain node when you run your own node.

To be able to do this, you will need to encode the RAW transaction data and sign this data with the respective Venly-wallet. The resulting signature can then be used to submit the transaction to the blockchain.

This page shows examples of retrieving the signature for different chains.

Endpoint

Requires Authority: sign:wallets

POSThttps://api-wallet.venly.io/api/signatures

Authorization

OAuth2

Body

application/json

pincodestring

signatureRequestone of

BuildEip712SignatureRequest (object)BuildMessageSignatureRequest (object)

Response

200400401403404405415429500

OK

Body

*/*

successboolean

resultone of

Signature (object)HexSignature (object)RawSignature (object)SubmittedAndSignedTransactionSignature (object)TransactionSignature (object)

Request

JavaScriptCurl

const response = await fetch('https://api-wallet.venly.io/api/signatures', {
    method: 'POST',
    headers: {
      "Content-Type": "application/json"
    },
    body: JSON.stringify({}),
});
const data = await response.json();

Response

{
  "success": true,
  "result": {
    "type": "HEX_SIGNATURE"
  }
}

Request Body

The body for the endpoint depends on which chain the transaction is for. First, there is a set of common fields and then there are some custom fields per (type of) chain.

Note that there is a difference between creating a transaction for a native token transfer or calling a contract:

• For native token transactions, the provided API can be used as described, without providing a data element. No encoded function is needed.

• For calling contracts or doing (ERC-20, ERC-721, or ERC-1155) token transactions, which are basically contract calls as well (safeTransferFrom function), you'll need to construct the (transaction-)data yourself. There are a number of libraries that allow you to build the encoded transaction data (e.g. web3j for Java, web3py for Python, etc.) In web3j, building the encoded function looks something like this: List inputParams = new ArrayList(); List outputParams = new ArrayList(); Function function = new Function("fuctionName", inputParams, outputParams); String encodedFunction = FunctionEncoder.encode(function) The encodedFunction is what needs to be passed as data in the Request Body.

Types

ETHEREUM_TRANSACTION , BSC_TRANSACTION , AVAC_TRANSACTION , MATIC_TRANSACTION , GOCHAIN_TRANSACTION , VECHAIN_TRANSACTION , BITCOIN_TRANSACTION , LITECOIN_TRANSACTION , AETERNITY_TRANSACTION , NEO_NATIVE_TRANSACTION , NEO_GAS_TRANSACTION, HEDERA_TRANSACTION

Common Fields

{
  pincode!: string,
  walletId!: string,
  submit!: boolean,
  type!: Type
}

Field	Type	Mandatory	Description
pincode	String	✅	The PIN code of the wallet that needs to sign for this request.
walletId	String	✅	The ID of the wallet you want to use to sign the transaction.
submit	boolean	✅	Whether or not you also immediately want to submit the transaction to the blockchain.
type	Type	✅	The type of transaction you are trying to sign. See Typesfor the possible values.

Custom Fields

EVM based chains

This applies to the following types ETHEREUM_TRANSACTION , BSC_TRANSACTION , AVAC_TRANSACTION , MATIC_TRANSACTION and GOCHAIN_TRANSACTION .

{
  pincode!: string,
  walletId!: string,
  submit!: boolean,
  type!: Type,
  
  to!: string,
  value?: number,
  data?: string,
  gas!: number,
  gasPrice!: number,
  nonce!: number
}

Field	Type	Mandatory?	Description
to	String	✅	The destination of the transaction.
value	number	❌	The amount of native currency in wei (e.g. Ether, Matic, BNB) you want to include in the transaction.
data	String	❌	The data you want to include in the transaction (if any). Here you can for example add an encoded contract call (encodedFunction).
gas	number	✅	The max amount of gas (gas limit) this transaction is allowed to use.
gasPrice	number	✅	The price in wei that you want to pay for one amount of gas.
nonce	number	✅	The nonce (sequence) of the transaction.

If you want a prediction of the gas/gasPrice and the next nonce, you can submit the request first to POST /signatures/prepare (leaving these fields empty). This will then return you a gas estimate + the next nonce.

Vechain Transaction

{
  pincode!: string,
  walletId!: string,
  submit!: boolean,
  type!: VECHAIN_TRANSACTION,
  
  blockRef?: string,
  chainTag?: string,
  expiration?: number,
  gas?: number,
  gasPriceCoef?: number,
  nonce?: string,
  clauses!: [{
    to!: string,
    amount?: number,
    data?: string
  }] 
}

Bitcoin Transaction

 {
  pincode!: string,
  walletId!: string,
  submit!: boolean,
  type!: BITCOIN_TRANSACTION,
  
  to!: string,
  value?: number,
  feePerByte?: number
}

Litecoin Transaction

{
  pincode!: string,
  walletId!: string,
  submit!: boolean,
  type!: LITECOIN_TRANSACTION,
  
  to!: string,
  value?: number,
  feePerKiloByte?: number
}

AEternity Transaction

{
  pincode!: string,
  walletId!: string,
  submit!: boolean,
  type!: AETERNITY_TRANSACTION,
  
  to!: string,
  value?: number,
  data?: string,
  nonce?: number,
  fee?: number,
  ttl?: number
}

Neo native Transaction

{
  pincode!: string,
  walletId!: string,
  submit!: boolean,
  type!: NEO_NATIVE_TRANSACTION,
  
  to!: string,
  value?: number
}

Neo gas Transsaction

{
  pincode!: string,
  walletId!: string,
  submit!: boolean,
  type!: NEO_GAS_TRANSACTION,
  
  to!: string,
  value?: number
}

Hedera Transaction

{
  pincode!: string,
  walletId!: string,
  submit!: boolean,
  type!: HEDERA_TRANSACTION,
  
  data?: string
}

Response

{
  type!: 'TRANSACTION_SIGNATURE',
  signedTransaction!: string
}