addTransaction

Introduction

The addTransaction method is the primary endpoint for creating and broadcasting a standard IXI payment transaction. It provides two modes of operation: a simple mode where the node automatically selects the necessary inputs from a wallet, and an advanced "coin control" mode where the user can specify the exact inputs to use.

Upon successful creation and validation, the transaction is added to the local pending pool and broadcast to the network for inclusion in an upcoming block.

Request

Requests can be made using either HTTP POST with a JSON body (recommended for complex requests) or HTTP GET with URL query parameters (useful for simple queries and browser-based access).

Parameters

Custom to and from Format

The to and from parameters use a special string format to encode multiple recipients or inputs:

• Each entry is composed of an address and an amount separated by an underscore (_).
• Multiple entries are separated by a hyphen (-).

Example: 16NBH...Bo_1000-1EXSq...Wm_50.25 sends 1000 IXI to the first address and 50.25 IXI to the second.

Example POST Request

This example sends 12.5 IXI, letting the node automatically select inputs and calculate the fee.

POST /addTransaction
Content-Type: application/json

{
  "jsonrpc": "2.0",
  "method": "addTransaction",
  "params": {
    "wallet": "1EXSqPpj49ZmKiWF8stsMsMXVnSfkee7EzTaBakwNn9sJdaWm",
    "to": "16NBHjLGJnmWGWjoRj1Tz5TebgwhAtN2ewDThrDp1HfKuhJBo_12.5"
  },
  "id": 1
}

Example GET Request

The params object is flattened into URL query string parameters. Special characters in parameter values must be URL-encoded.

GET /addTransaction?wallet=1EXSqPpj49ZmKiWF8stsMsMXVnSfkee7EzTaBakwNn9sJdaWm&to=16NBHjLGJnmWGWjoRj1Tz5TebgwhAtN2ewDThrDp1HfKuhJBo_12.5

Response

The response format is a standard JSON-RPC object, regardless of whether the request was made via GET or POST. The result is a JSON object containing the details of the created transaction.

Result: Transaction Object Structure

Example Success Response

{
  "jsonrpc": "2.0",
  "result": {
    "id": "68874-prFPNo1GeQ8HzwPMnuFEGSXiq9qRyUL7gFxiaE5FaKPL8BTZodJBcZ5L81n9",
    "version": 7,
    "blockHeight": "68874",
    "nonce": "334231",
    "signature": "6b26d...f7",
    "pubKey": "1GjPT...hMA",
    "timestamp": "1763041074",
    "type": "0",
    "amount": "1000.00000000",
    "applied": "0",
    "checksum": "932a7...8b82",
    "from": {
      "1": "1000.01000000"
    },
    "to": {
      "16NBHjLGJnmWGWjoRj1Tz5TebgwhAtN2ewDThrDp1HfKuhJBo": "1000.00000000"
    },
    "fee": "0.01000000",
    "totalAmount": "1000.01000000"
  },
  "id": 1
}```

### Example Error Response

```json
{
    "jsonrpc": "2.0",
    "result": null,
    "id": 1,
    "error": {
        "code": -32001,
        "message": "Balance is too low"
    }
}

Behavioral Notes

• Automatic Input Selection (Simple Mode): If the from parameter is omitted, the node will automatically find and select the necessary inputs from the specified wallet to cover the sum of all to amounts plus the dynamically calculated transaction fee. This is the recommended mode for most users.

• Manual Input Selection (Advanced Mode): If the from parameter is provided, you take full control of the transaction's inputs.

  • Without autofee: You are responsible for ensuring the math is correct. The sum of all from amounts must exactly equal the sum of all to amounts plus the final, size-dependent transaction fee. The API will return an error if the values do not match.
  • With autofee=true: The node will calculate the required transaction fee and automatically add it to the first input specified in your from list. The remaining from and to amounts are then balanced. This is the recommended way to use manual input selection.

• Dynamic Fee Calculation: The final transaction fee is dependent on the transaction's byte size. The node may perform several internal iterations, adjusting the fee and re-selecting inputs (in automatic mode) to find the correct balance. The fee in the response object is the final, correct fee.

• Relay Fees for Clients: If this call is made from a client-type node, it will automatically add small outputs to the transaction to pay S2 relay nodes. These relay fees are added to the total amount that must be covered by the transaction inputs.