construction/parse - Cardano

Example code for the construction/parse JSON-RPC method. Complete guide on how to use construction/parse JSON-RPC in GetBlock Web3 documentation.

This endpoint parses a transaction, signed or unsigned, back into its operations. It is used to confirm a constructed transaction matches the original intent before signing or submitting.

Parameters

The request body is a JSON object with the following fields.

Field	Type	Required	Description
network_identifier	object	Yes	The network to parse for
signed	boolean	Yes	Whether the supplied transaction is signed
transaction	string	Yes	The transaction CBOR hex to parse

Request

cURL

curl --location --request POST 'https://go.getblock.io/<ACCESS-TOKEN>/construction/parse' \
--header 'Content-Type: application/json' \
--data-raw '{
    "network_identifier": {
        "blockchain": "cardano",
        "network": "mainnet"
    },
    "signed": false,
    "transaction": "a400818258200e...unsigned-cbor..."
}'

JavaScript

example.js

const response = await fetch(
    'https://go.getblock.io/<ACCESS-TOKEN>/construction/parse',
    {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({"network_identifier": {"blockchain": "cardano", "network": "mainnet"}, "signed": false, "transaction": "a400818258200e...unsigned-cbor..."})
    }
);
console.log(await response.json());

Python

example.py

import requests

response = requests.post(
    'https://go.getblock.io/<ACCESS-TOKEN>/construction/parse',
    headers={'Content-Type': 'application/json'},
    json={"network_identifier": {"blockchain": "cardano", "network": "mainnet"}, "signed": false, "transaction": "a400818258200e...unsigned-cbor..."}
)

print(response.json())

Response

{
    "operations": [
        {
            "operation_identifier": {
                "index": 0
            },
            "type": "output",
            "account": {
                "address": "addr1qxy2lpan99fcnhhyzr8w8qk4dqz4mp7g6b8h3r2v5c9d0e1f2g3h4j5k6l7m8n9p0q"
            },
            "amount": {
                "value": "9240398",
                "currency": {
                    "symbol": "ADA",
                    "decimals": 6
                }
            }
        }
    ],
    "account_identifier_signers": []
}

Response Parameters

Field	Type	Description
operations	array	The operations decoded from the transaction
account_identifier_signers	array	Accounts that signed, for a signed transaction

Use Cases

• Intent Verification: Confirm a built transaction matches the intent

• Signer Checks: Read which accounts signed a transaction

• Debugging: Inspect the operations of a constructed transaction

• Safety: Validate a transaction before submitting it

Error Handling

Error Code	Message	Description
1	Invalid request	A required construction field is missing or malformed
6	Transaction decode failed	The supplied transaction could not be decoded
14	Invalid signature	A supplied signature is malformed or does not match
5	Internal error	The node failed to process the construction step