Call preview

Scrypto Call Preview

Preview a scrypto function or method call against the latest network state. Returns the result of the scrypto function or method call.

POSThttps://xrd.nownodes.io/core/transaction/call-preview

Body

application/json

network*NetworkIdentifier (string)

The logical name of the network

Example: "{{network}}"

at_ledger_stateLedgerStateSelector (object)

An optional specification of a historical ledger state at which to execute the request. The "historical state" feature (see the db.historical_substate_values.enable flag) must be enabled on the Node, and the requested point in history must be recent enough (in accordance with the Node's configured state_hash_tree.state_version_history_length).

target*TargetIdentifier (object)

arguments*array of string

Argument list

Response

200400500

Result of the scrypto function call

Body

application/json

at_ledger_state*LedgerStateSummary (object)

status*TransactionStatus (enum)

The status of the transaction

SucceededFailedRejected

outputSborData (object)

Various representations of an SBOR payload. Some endpoints may allow opting in/out of each representation.

error_messagestring

Error message (only present if status is Failed or Rejected)

Request

JavaScriptCurlPython

const response = await fetch('https://xrd.nownodes.io/core/transaction/call-preview', {
    method: 'POST',
    headers: {
      "Content-Type": "application/json"
    },
    body: JSON.stringify({
      "target": {
        "type": "method",
        "component_address": "component_loc1qftacppvmr9ezmekxqpq58en0nk954x0a7jv2zz0hc7qfxlgx4",
        "method_name": "lock_fee"
      },
      "arguments": [
        "a120000000000010632d5ec66b050000000000000000000000000000000000000000000000"
      ]
    }),
});
const data = await response.json();

Response

200400500

{
  "at_ledger_state": {
    "state_version": 0,
    "header_summary": {
      "epoch_round": {
        "epoch": 0,
        "round": 0
      },
      "ledger_hashes": {
        "state_tree_hash": "text",
        "transaction_tree_hash": "text",
        "receipt_tree_hash": "text"
      },
      "proposer_timestamp": {
        "unix_timestamp_ms": 0,
        "date_time": "text"
      }
    }
  },
  "status": "Succeeded",
  "output": {
    "hex": "text"
  },
  "error_message": "text"
}