I’m trying to send custom coins (not just APT) on Aptos using a keyless wallet, but I keep getting InvalidCoinType or a BigInt related errorQuestion Title

[DefenceHack]

Discord user ID

kentwood261

Describe your question in detail.

I’m trying to send custom coins (not just APT) on Aptos using a keyless wallet, but I keep getting InvalidCoinType or a BigInt related error
{ "message": "Failed to submit transaction", "error_code": "InvalidCoinType", "vm_error_code": null }

What error, if any, are you getting?

No response

What have you tried or looked at? Or how can we reproduce the error?

No response

Which operating system are you using?

macOS

Which SDK or tool are you using? (if any)

TypeScript SDK

Describe your environment or tooling in detail

No response

[Skamina]

Base on what I understand this may happen because of 3 reasons:

1.Incorrect Coin Type Specified: Whenever you're sending a custom coin, you need to correctly specify the coin's type, which usually involves providing the full struct tag of the coin. So now try to double-check that you are using the exact, case-sensitive struct tag for the custom coin you are trying to send.

Secondly

2. Coin Not Registered: it may be because the recipient account might not have the specific custom coin type registered. In Aptos, accounts need to explicitly opt-in to hold a particular coin type.So try double-check that also.

And thirdly

3. Incorrect Handling in Keyless Wallet Implementation: There might be an issue in how the keyless wallet implementation you are using handles custom coin types. Ensure the wallet SDK or library you are using correctly supports sending arbitrary coin types.

Hope this may help 🙏

[Pcharlesme]

Yes , you are right also Incorrect handling of decimal places can also cause that

[Skamina]

Thank you sir

[Skamina]

• Use a block explorer or the Aptos CLI to verify and confirm the exact coin type (struct tag) of the custom coin you are trying to send.
• Also ensure the recipient account has initialized the resource account for the custom coin, which you need to Check Recipient Account
• Consult the documentation of the keyless wallet SDK or library you are using for specific instructions on sending custom coins by Review Keyless Wallet Documentation
• And lastly Examine Transaction Construction by Carefully reviewing the code where you construct the transaction to send the custom coin, paying close attention to how the coin type is specified.

[Pcharlesme]

Invalid coinType format — the coinType string must exactly match the on-chain type, e.g., 0x1::aptos_coin::AptosCoin or your custom token's full type. @DefenceHack

[Pcharlesme]

Use BigInt when dealing with high-value transfers or coins with 18+ decimals:
const rawAmount = BigInt(Math.floor(amount * 10 ** Number(decimal)));

 const transaction = await aptos.transferCoinTransaction({
     amount: rawAmount,
     sender: keylessAccount.accountAddress,
     recipient,
     coinType,
   });

   const committedTxn = await aptos.signAndSubmitTransaction({
     signer: keylessAccount,
     transaction,
   });

   const committedTransactionResponse = await aptos.waitForTransaction({
     transactionHash: committedTxn.hash,
   });

[DefenceHack]

Thanks for your contributions