deleteAllowance

How to call the API from an app

Hedera Wallet Snap connects to your currently connected Metamask account by default. To learn how apps can connect to Hedera Wallet Snap using a non-metamask(external) account, refer to this documentation.

Then, depending on whether you're trying to connect to a metamask account or a non-metamask account, you can call the snap API in the following way:

const snapId = `npm:@hashgraph/hedera-wallet-snap`

const deleteAllowanceAPI = async () => {
  const externalAccountParams = {
    externalAccount: {
      accountIdOrEvmAddress: '0.0.12345',
      curve: 'ED25519'
    }
  }

  await window.ethereum.request({
    method: 'wallet_invokeSnap',
    params: {
      snapId,
      request: {
        method: 'deleteAllowance',
        params: {
          network: 'testnet',
          assetType: 'HBAR', // 'HBAR' | 'TOKEN' | 'NFT'
          spenderAccountId: '0.0.67890', 
          /* 
            Uncomment the below line if you want to connect 
            to a non-metamask account
          */
          // ...externalAccountParams
        }
      }
    }
  })
}

Note that you can also call this API to delete allowance for other tokens and nfts.

For tokens, you would need to pass in additional parameters as shown below:

const snapId = `npm:@hashgraph/hedera-wallet-snap`

  await window.ethereum.request({
    method: 'wallet_invokeSnap',
    params: {
      snapId,
      request: {
        method: 'deleteAllowance',
        params: {
          network: 'testnet',
          assetType: 'TOKEN',
          spenderAccountId: '0.0.67890'
          assetId: '0.0.45634' // This is token ID
        }
      }
    }
  })
}

For nfts, you would need to pass in additional parameters as shown below:

const snapId = `npm:@hashgraph/hedera-wallet-snap`

  await window.ethereum.request({
    method: 'wallet_invokeSnap',
    params: {
      snapId,
      request: {
        method: 'approveAllowance',
        params: {
          network: 'testnet',
          assetType: 'NFT',
          assetId: '0.0.57894' // This is nft ID
        }
      }
    }
  })
}

What the API does

  1. Retrieves the currently connected account the user has selected on Metamask. If it's the first time, a new snap account is created and the account info is saved in snap state.

  2. Calls the Hedera SDK Delete Allowance API that allows a token owner to delete allowances. For NFTs, deleteAllTokenNftAllowances is called to delete the allowances for the given NFT ID. For hbar and fungible tokens, approveTokenAllowance is called with the amount of 0 to delete the allowances.

  3. Returns the transaction receipt as response.

Some example responses:

For a hedera account id 0.0.4559:

{
  "currentAccount": {
    "hederaAccountId": "0.0.4559",
    "hederaEvmAddress": "0x3ba201df50314e4702d4d92b52d304ee63bfca23",
    "balance": {
      "hbars": 89.60420503,
      "timestamp": "2024-02-01T21:35:21.826Z",
      "tokens": {}
    },
    "network": "testnet"
  },
  "receipt": {
    "status": "SUCCESS",
    "accountId": "",
    "fileId": "",
    "contractId": "",
    "topicId": "",
    "tokenId": "",
    "scheduleId": "",
    "exchangeRate": {
      "hbars": 1,
      "cents": 12,
      "expirationTime": "Mon, 25 Nov 1963 17:31:44 GMT",
      "exchangeRateInCents": 12
    },
    "topicSequenceNumber": "0",
    "topicRunningHash": "",
    "totalSupply": "0",
    "scheduledTransactionId": "",
    "serials": [],
    "duplicates": [],
    "children": []
  }
}

Live Demo on CodePen

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