Transaction Labeling FAQs

The Moralis Transaction API automatically decodes raw transaction input data into human-readable events based on the functions and events defined within the associated contract ABI, such as "Transfer", "Approve", "Mint", "Deposit", etc.

This means that for each transaction and log we apply a friendly, easily recognizable label, making it easier than ever to understand and navigate the complex world of blockchain.

Each transaction includes a decoded_call object which is the decoded input data of the transaction, whilst each log includes a decoded_event object which is the decoded topic data.

Which endpoints support Transaction labeling?

We have included support for transaction labeling on two new endpoints:

Name	Endpoint
Get decoded transactions by wallet	/:address/verbose
Get decoded transaction by hash	/transaction/:transaction_hash/verbose

Why are some transactions not decoded?

We only decode transactions from verified ABIs. We are continuously adding to our repository of verified contract ABIs.

If transaction is related to an unverified contract, or it's part of a verified contract that do not yet support, transactions will have a decoded_call of null and logs will have a decoded_event of null.

For unsupported ABIs, we have future plans to make submissions available via the API, however until this time, if you would like an ABI to be supported, please add your submissions to our ABI requests board.

What chains currently support transaction labeling?

All of our EVM blockchains support transaction labeling, with the highest contract coverage on Ethereum.

Will you continue to add new contract ABIs?

Yes, absolutely! We plan to continue adding verified contract ABIs to our repository. We have plans to make this automatic in future, however until this time, if you would like an ABI to be supported please add your submissions to our ABI requests board.

What are some use cases of Transaction labeling?

Transaction labeling can be a powerful feature in a number of different use cases. Here are some popular ones:

• Displaying a clear timeline of events for a given wallet
• Identifying different types of transactions for specific use-cases, such as taxable events
• Building an intuitive block explorer

A decoded example

As an example, we can see that Ethereum transaction 0x012b9b98e21664117ec0b499d726a39f492ac8bd402cca8bebcbd163b9f75760 is labelled as a Transfer on Etherscan:

If we look at this transaction in more detail on Etherscan, we can see that the transaction has the following input data:

and when decoded, this input data looks like:

Similarly, this transaction also has 1 log associated with it:

It is this data which is now decoded and included per transaction. Here is the full transaction data served through the Moralis API, note the decoded_call at the transaction level, as well as the decoded_event at the log level:

{
  "hash": "0x012b9b98e21664117ec0b499d726a39f492ac8bd402cca8bebcbd163b9f75760",
  "nonce": "567407",
  "transaction_index": "153",
  "from_address": "0x48c04ed5691981c42154c6167398f95e8f38a7ff",
  "to_address": "0x2b591e99afe9f32eaa6214f7b7629768c40eeb39",
  "value": "0",
  "gas": "180000",
  "gas_price": "41000000000",
  "input": "0xa9059cbb000000000000000000000000eafeba1882a066a4ecca2f9d596cd0c4e722bfda000000000000000000000000000000000000000000000000000000b4ec8a8e9a",
  "receipt_cumulative_gas_used": "11843646",
  "receipt_gas_used": "51617",
  "receipt_contract_address": null,
  "receipt_root": null,
  "receipt_status": "1",
  "block_timestamp": "2023-02-15T14:51:23.000Z",
  "block_number": "16634851",
  "block_hash": "0x83e09485f7dc9fdef520ae59bbc02ebbca2e2508fc6b7fa5fe6da93a21c71272",
  "transfer_index": [
    16634851,
    153
  ],
  "logs": [
    {
      "log_index": "285",
      "transaction_hash": "0x012b9b98e21664117ec0b499d726a39f492ac8bd402cca8bebcbd163b9f75760",
      "transaction_index": "153",
      "transaction_value": "0",
      "address": "0x2b591e99afe9f32eaa6214f7b7629768c40eeb39",
      "data": "0x000000000000000000000000000000000000000000000000000000b4ec8a8e9a",
      "topic0": "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef",
      "topic1": "0x00000000000000000000000048c04ed5691981c42154c6167398f95e8f38a7ff",
      "topic2": "0x000000000000000000000000eafeba1882a066a4ecca2f9d596cd0c4e722bfda",
      "topic3": null,
      "block_timestamp": "2023-02-15T14:51:23.000Z",
      "block_number": "16634851",
      "block_hash": "0x83e09485f7dc9fdef520ae59bbc02ebbca2e2508fc6b7fa5fe6da93a21c71272",
      "transfer_index": [
        16634851,
        153,
        285
      ],
      "decoded_event": {
        "signature": "Transfer(address,address,uint256)",
        "label": "Transfer",
        "type": "event",
        "params": [
          {
            "name": "from",
            "value": "0x48c04ed5691981C42154C6167398f95e8f38a7fF",
            "type": "address"
          },
          {
            "name": "to",
            "value": "0xeafebA1882a066A4eCcA2F9d596Cd0c4E722BfDa",
            "type": "address"
          },
          {
            "name": "value",
            "value": "777062616730",
            "type": "uint256"
          }
        ]
      }
    }
  ],
  "decoded_call": {
    "signature": "transfer(address,uint256)",
    "label": "transfer",
    "type": "function",
    "params": [
      {
        "name": "_to",
        "value": "0xeafebA1882a066A4eCcA2F9d596Cd0c4E722BfDa",
        "type": "address"
      },
      {
        "name": "_value",
        "value": "777062616730",
        "type": "uint256"
      }
    ]
  }
}