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

  await window.ethereum.request({
    method: 'wallet_invokeSnap',
    params: {
      request: {
        method: 'hts/createToken',
        params: {
          network: 'testnet',
          tokenId: '0.0.4284930'
          name?: 'NewTuum',
          symbol?: 'NEWTUUM',
          tokenMemo?, // Optional param - type: string
          treasuryAccountId?: // Optional param - type: string
          adminPublicKey?, // Optional param - type: string
          kycPublicKey?, // Optional param - type: string
          freezePublicKey?, // Optional param - type: string
          pausePublicKey?, // Optional param - type: string
          wipePublicKey?, // Optional param - type: string
          supplyPublicKey?, // Optional param - type: string
          feeSchedulePublicKey?, // Optional param - type: string
          expirationTime?, // Optional param - type: string
          autoRenewAccountId?, // Optional param - type: string
          autoRenewPeriod?, // Optional param - type: number
            Uncomment the below line if you want to connect 
            to a non-metamask account
          // ...externalAccountParams
  • At least one optional parameter must be passed before calling this API or it will fail

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. Parses the arguments that were passed

  3. Calls the Hedera SDK Update Token API to update the properties of the existing token. The admin key must sign this transaction to update any of the token properties. With one exception. All secondary keys can sign a transaction to change themselves. The admin key can update exisitng keys, but cannot add new keys if they were not set during the creation of the token. If no value is given for a field, that field is left unchanged.

  4. This action cannot be called if this token was created without the admin key being set during token creation. Furthermore, this action must also be called using the same public key account.

  5. Returns the transaction receipt as response

An example response:

    "currentAccount": {
        "metamaskEvmAddress": "0x0b3628d1b838993b5fceec8b2a26502e7a8e5241",
        "externalEvmAddress": "",
        "hederaAccountId": "0.0.3581604",
        "hederaEvmAddress": "0xca53f9c93d30e0b7212d67901e5a24fb090d542b",
        "publicKey": "0x0206022cea4c6dd6d2e7263b8802253971de922f5380661d97cba82dee66f57ad6",
        "balance": {
            "hbars": 88.14341532,
            "timestamp": "Fri, 26 Apr 2024 17:29:26 GMT",
            "tokens": {
                "0.0.4279119": {
                    "balance": 50,
                    "decimals": 1,
                    "tokenId": "0.0.4279119",
                    "name": "Tuum",
                    "symbol": "TUUM",
                    "tokenType": "FUNGIBLE_COMMON",
                    "supplyType": "INFINITE",
                    "totalSupply": "50",
                    "maxSupply": "0"
        "network": "testnet",
        "mirrorNodeUrl": ""
    "receipt": {
        "status": "SUCCESS",
        "accountId": "",
        "fileId": "",
        "contractId": "",
        "topicId": "",
        "tokenId": "",
        "scheduleId": "",
        "exchangeRate": {
            "hbars": 30000,
            "cents": 331526,
            "expirationTime": "Fri, 26 Apr 2024 18:00:00 GMT",
            "exchangeRateInCents": 11.050866666666666
        "topicSequenceNumber": "0",
        "topicRunningHash": "",
        "totalSupply": "0",
        "scheduledTransactionId": "",
        "serials": [],
        "duplicates": [],
        "children": []

Live Demo on CodePen

Some things to keep in mind while interacting with the above demo
  • If you're getting any errors with the live demo, make sure you go through the FAQs section to learn about what you may be missing. You need to install Metamask in your browser for the live demo to work

To ease the integration of Hedera Wallet Snap on an application, we have created a template web application that you can run locally and check out the code in its entirety to learn how you can integrate and interact with various APIs exposed by Hedera Wallet Snap. Check out the full source code at template application github repository.

You can also check out the API reference to learn how each API works.

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