Vouchers

Vouchers represent transactions that can be carried out on the base layer blockchain, such as asset transfers. They are used to effect changes in the base layer based on the application's state.

1. Get Voucher by Index

Retrieve a specific voucher based on its index and associated input index.

query voucher($voucherIndex: Int!, $inputIndex: Int!) {
  voucher(voucherIndex: $voucherIndex, inputIndex: $inputIndex) {
    index
    input {
      index
      timestamp
      msgSender
      blockNumber
    }
    destination
    payload
    proof {
      validity {
        inputIndexWithinEpoch
        outputIndexWithinInput
        outputHashesRootHash
        vouchersEpochRootHash
        noticesEpochRootHash
        machineStateHash
        outputHashInOutputHashesSiblings
        outputHashesInEpochSiblings
      }
      context
    }
  }
}

For vouchers, the API provides access to proof data that can be used for validation on the base layer blockchain. This proof data is accessible through the Proof field on voucher objects.

Arguments

Name	Type	Description
voucherIndex	Int!	The index of the voucher to retrieve.
inputIndex	Int!	The index of the associated input.

Response Type

Voucher

2. Get Vouchers

Retrieve a list of vouchers with support for pagination.

query vouchers($first: Int, $after: String) {
  vouchers(first: $first, after: $after) {
    edges {
      node {
        index
        input {
          index
          timestamp
          msgSender
          blockNumber
        }
        destination
        payload
      }
      cursor
    }
    pageInfo {
      hasNextPage
      endCursor
    }
  }
}

Arguments

Name	Type	Description
first	Int	Number of vouchers to retrieve (for pagination).
after	String	Cursor to start retrieving vouchers from (for pagination).

Response Type

VoucherConnection

3. Get Vouchers by Input

Retrieve vouchers associated with a specific input.

query vouchersByInput($inputIndex: Int!, $first: Int, $after: String) {
  input(index: $inputIndex) {
    vouchers(first: $first, after: $after) {
      edges {
        node {
          index
          destination
          payload
        }
        cursor
      }
      pageInfo {
        hasNextPage
        endCursor
      }
    }
  }
}

Arguments

Name	Type	Description
inputIndex	Int!	Index of the input to retrieve vouchers for.
first	Int	Number of vouchers to retrieve (for pagination).
after	String	Cursor to start retrieving vouchers from (for pagination).

Response Type

VoucherConnection

Examples

1. Fetching a specific voucher:

     query {
       voucher(voucherIndex: 3, inputIndex: 2) {
         index
         destination
         payload
         proof {
           validity {
             inputIndexWithinEpoch
             outputIndexWithinInput
           }
           context
         }
       }
     }

2. Listing earlier(first 5) vouchers:

   query {
     vouchers(first: 5) {
       edges {
         node {
           index
           input {
             index
             timestamp
           }
           destination
           payload
         }
         cursor
       }
       pageInfo {
         hasNextPage
         endCursor
       }
     }
   }

3. Retrieving vouchers associated with a specific input:

   query {
     input(index: 10) {
       vouchers(first: 3) {
         edges {
           node {
             index
             destination
             payload
           }
           cursor
         }
         pageInfo {
           hasNextPage
           endCursor
         }
       }
     }
   }