Invoke Script Transaction

Invoke Script transaction invokes the callable function of the dApp. Learn more about dApp and script invocation

In addition to the dApp address, callable function name, and arguments, the Invoke Script transaction can contain payments to dApp. The maximum number of payments is 10. (Before activation of feature #16 “Ride V5, dApp-to-dApp invocations”, the maximum number of payments was 2. Before activation of feature #15 “Ride V4, VRF, Protobuf, Failed transactions”, the maximum number of payments was 1.)

Fee

The sender can specify a transaction fee nominated in a sponsored asset instead of WAVES, see the Sponsored Fee article.

The minimum fee in WAVES for an Invoke Script transaction is calculated as follows:

Fee = 0.005 + S + 1 × I

• If the transaction sender is a dApp or smart account, and that the complexity of the account script or dApp script verifier function exceeds the sender complexity threshold, then S = 0.004, otherwise S = 0.
• I is the number of issued assets that are not NFT.

Before activation of feature #16 “Ride V5, dApp-to-dApp invocations”

• The minimum fee was increased by 0.004 WAVES for each execution of asset script in payments and script actions.
• The extra fee of 0.004 WAVES was required for transactions sent from smart account or dApp regardless of the complexity of the account script or the presence and complexity of the dApp script verifier function.)

Total Complexity

A dApp callable function can invoke a callable function of another dApp, or another callable function of the same dApp, or even itself. All invoked functions are executed within a single Invoke Script transaction. More about dApp-to-dApp invocation

DApp-to-dApp invocation is enabled by feature #16 “Ride V5, dApp-to-dApp invocations”.

The total complexity is limited by 26,000 for all callable functions and asset scripts of involved smart assets in a single Invoke Script transaction. The sender's account script complexity is not included in that limit. (Before activation of feature #16 “Ride V5, dApp-to-dApp invocations” the total complexity was not limited.)

JSON Representation

{
  "type": 16,
  "id": "DN9Ny8mph4tLjn58e9CqhckPymH9zwPqBSZtcv2bBi3u",
  "sender": "3Mw48B85LvkBUhhDDmUvLhF9koAzfsPekDb",
  "senderPublicKey": "BvJEWY79uQEFetuyiZAF5U4yjPioMj9J6ZrF9uTNfe3E",
  "fee": 500000,
  "feeAssetId": null,
  "timestamp": 1601652119485,
  "proofs": [
    "2536V2349X3cuVEK1rSxQf3HneJwLimjCmCfoG1QyMLLq1CNp6dpPKUG3Lb4pu76XqLe3nWyo3HAEwGoALgBhxkF"
  ],
  "version": 2,
  "chainId": 84,
  "dApp": "3N28o4ZDhPK77QFFKoKBnN3uNeoaNSNXzXm",
  "payment": [],
  "call": {
    "function": "foo",
    "args": [
      {
        "type": "list",
        "value": [
          {
            "type": "string",
            "value": "alpha"
          },
          {
            "type": "string",
            "value": "beta"
          },
          {
            "type": "string",
            "value": "gamma"
          }
        ]
      }
    ]
  },
  "height": 1203100,
  "applicationStatus": "succeeded",
  "stateChanges": {
    "data": [
      {
        "key": "3Mw48B85LvkBUhhDDmUvLhF9koAzfsPekDb",
        "type": "string",
        "value": "alphabetagamma"
      }
    ],
    "transfers": [],
    "issues": [],
    "reissues": [],
    "burns": [],
    "sponsorFees": [],
    "leases": [],
    "leaseCancels": [],
    "invokes": []
  }
}

Field	Description
call.function	Callable function name. Up to 255 bytes (1 character can take up to 4 bytes)
call.args.type	Argument type: - binary - boolean - integer - string - list (lists are available after activation of feature #15)
call.args.value	Argument value. - integer: from -9,223,372,036,854,775,808 to 9,223,372,036,854,755,807 inclusive. - string or binary: up to 32,767 bytes. Binary value should be base64 encoded. - list: up to 1000 elements
dApp	dApp address base58 encoded or dApp alias with alias:<chain_id>: prefix, for example alias:T:merry (see Chain ID)
payment.amount	Amount of token in payment: an integer value specified in atomic units
payment.assetId	ID of token in payment, base58 encoded. null means that the payment is in WAVES
stateChanges	Script actions performed by the callable function and dApp-to-dApp invocation results

The stateChanges structure does not need to be filled when sending a transaction, and it is not stored on the blockchain. The node returns this structure when providing transaction data via the REST API.

The fields that are common to all types of transactions are described in the Transaction article.

Binary Format

See the Invoke Script Transaction Binary Format article.

Ride Structure

The InvokeScriptTransaction structure is used for transaction handling in smart contracts.