Transaction Receipts

Confirmed transactions come with a receipt under the result field when fetching the transaction in JSON format.

Basic Fields

The following are the fields a receipt may have. These fields generally apply to both payment and contract transactions.

Field	Type	Description
cumulative_gas	string	The total gas consumed in this transaction
epoch_num	string	The epoch number in which this transaction was confirmed
success	boolean	The result of this transaction (`true` on success)

For example:

"receipt": {
  "cumulative_gas": "10481",
  "epoch_num": "586524",
  "success": true
},

Additional Fields

For smart contract transactions, additional information relating to smart contract execution is contained in additional fields under the "receipt".

Successful Transactions

If a transaction is successful (i.e., the success field is true), these fields will be present:

Field	Type	Description
accepted	boolean	Indicates whether the last transition in this transaction incurred a balance transfer
event_logs	json-array	A list of event logs emitted by the contract during processing. Each log contains: _eventname: [string] The name of the event address: [string] The address of the contract that emitted this event params: [json-array] A list of parameters under the transition. Each entry contains: vname: [string] The name of the variable type: [string] The type of the variable value: [string] The value of the variable
transitions	json-array	A list of internal transitions invoked during the processing of the transaction by the Scilla interpreter. Each transition contains: addr: [string] The address of the contract account that emitted this transition depth: [int] The depth of the current transition. The transitions directly emitted by the recipient in the transaction will be in depth 0. If those transitions in depth 0 invoked transitions from other contracts, those will be in depth 1. And so on and so forth. msg: [json-object] The message field emitted by the Scilla interpreter, which includes: _amount: [string] The balance transferred from this transition _recipient: [string] The recipient of this transition, which can either be a wallet account or contract account _tag: [string] The contract-defined transition name params: [json-array] A list of parameters under the transition. Each entry contains: vname: [string] The name of the variable type: [string] The type of the variable value: [string] The value of the variable

For example:

"receipt": {
  "accepted": true,
  "cumulative_gas": "878",
  "epoch_num": "589742",
  "event_logs":[
    {
      "_eventname":"RecordsSet",
      "address":"0x708bfbba57436ed45efc13df9fab4249a354e06b",
      "params":[
        {
          "type":"ByStr20",
          "value":"0x9611c53be6d1b32058b2747bdececed7e1216793",
          "vname":"registry"
        },
        {
          "type":"ByStr32",
          "value":"0x2bb13c9b0a5dd28d42b470e2073df14608a9056310988b84b24dc342211e0627",
          "vname":"node"
        }
      ]
    },
  ],
  "success": true,
  "transitions": [
    {
      "addr": "0x9a65df55b2668a0f9f5f749267cb351a37e1f3d9",
      "depth": 0,
      "msg": {
        "_amount": "50000000000000",
        "_recipient": "0xc0e28525e9d329156e16603b9c1b6e4a9c7ed813",
        "_tag": "onFundsReceived",
        "params": {
          "vname": "emp_addr",
          "type": "ByStr20",
          "Value": "0x00345678901234567890123456789012345678ab"
        }
      }
    }
  ]
}

Unsuccessful Transactions

If a transaction is unsuccessful (i.e., the success field is false), no balance transfer will be executed. Additionally, these fields will be present:

Field	Type	Description
errors	json-object	An object containing a key-value field. The key [string] indicates the depth at which the error occurred. The value part is a JSON array that lists the error codes [int] reported. The list of possible error codes can be found here.
exceptions	json-array	A list of exceptions returned by the Scilla interpreter. Each exception contains: line”: [int] The line in the Scilla contract code where the exception was detected message: [string] The message describing the exception

For example:

"receipt": {
  "cumulative_gas": "1220",
  "epoch_num": "588004",
  "errors": {
    "0": [
      7
    ]
  },
  "exceptions": [
    {
      "line": 87,
      "message": "Exception thrown: (Message [(_exception : (String \"Error\")) ; (code : (Int32 -2))])"
    },
    {
      "line": 100,
      "message": "Raised from IsAdmin"
    },
    {
      "line": 137,
      "message": "Raised from ConfigureUsers"
    }
  ],
  "success": false
  }

Recommended Steps for Exchanges Polling for Incoming $ZIL Deposit from Smart Contract Transactions

Confirm that the success field is set to true.
Traverse the transitions JSON array. For each transition, for a successful deposit of $ZIL via the smart contract, the following must be fulfilled:
1. _recipient corresponds to a known deposit address controlled by the exchange.
2. _tag is either AddFunds or empty. !!! note
```
      `_tag` can be found under `msg` field. If either `_tag` or `msg` is not present, there is no incoming deposit from this particular transition.
```
3. _amount is non-zero.
4. Check the _recipient and _amount to complete the information on the balance transfer. In such a case, you can confirm that there is a deposit to address _recipient with value _amount (in Qa).
5. Continue traversing the remaining transitions and checking for more deposits.