Node RPC#

You can view node RPC methods here

Default RPC endpoint#

http://localhost:9009

RPC call example#

curl -X POST --data '{
                       "jsonrpc":"2.0",
                       "key":"myAPIkey",
                       "id":1,
                       "method":"dna_getCoinbaseAddr",
                       "params": []
                     }'

Address nonce#

Address nonce is a transaction counter in each Idena address. This prevents replay attacks where a transaction sending eg. 20 coins from A to B can be replayed by B over and over to continually drain A's balance. The nonce keeps track of how many transactions the sender has sent during the current epoch. Address nonce starts from 0 each epoch. Nonce is the transaction counter only of the sending address. It doesn't include transactions received by the address.

You can get the current account nonce by calling dna_getBalance method. Example:

{
  "method": "dna_getBalance",
  "params": [
    "<address>"
  ],
  "id": 0,
  "key": "<key>"
}

Response:

{
  "jsonrpc": "2.0",
  "id": 0,
  "result": {
    "stake": "1.727568288016598691",
    "balance": "7.376388954349732279",
    "nonce": 21
  }
}

Epoch#

You can get the current epoch using dna_epoch method. Example:

{
  "method": "dna_epoch",
  "params": [],
  "id": 0,
  "key": "<key>"
}

Response:

{
  "jsonrpc": "2.0",
  "id": 0,
  "result": {
    "epoch": 65,
    "nextValidation": "2021-03-30T15:30:00+02:00",
    "currentPeriod": "None",
    "currentValidationStart": "2021-03-30T15:30:00+02:00"
  }
}

Transaction nonce and epoch#

When sending transaction the current epoch number and subsequent nonce value should be specified for the sender address (address nonce+1).

Example:

{
  "method": "dna_sendTransaction",
  "params": [
    {
      "from": "<address>",
      "to": "<address>",
      "amount": "100",
      "maxFee": 0.1,
      "nonce": 22,
      "epoch": 65
    }
  ],
  "id": 0,
  "key": "<key>"
}

Transaction fees#

The transaction fee is calculated automatically by protocol. The fee goes up or down based on how full the previous block was, targeting an average block utilization of 50%. When the previous block is more than 50% full, the transaction fee goes up proportionally. When it is below 50% usage, fees go down.

transactionFee = currFeeRate * transactionSize

currFeeRate = max(
     1e-17,
     0.01/networkSize,
     prevFeeRate*(1+0.25*(prevBlockSize/300Kb-0.5))
    )

You can specify the maximum fee limit for the transaction maxFee.

Dust#

All addresses with balances less than dust are cleaned every time a new epoch starts. Dust coins are burnt to prevent spam and minimize the size of the blockchain state. You can calculate the dust size using the following formula:

10/networkSize

The smallest unit of iDNA#

The smallest unit of iDNA is 1e-18 iDNA (0.000000000000000001 iDNA).

Raw transactions#

You can build and sign raw transaction offline. See js examples. Actual protobuf model of transactions see here.