Leather Wallet Fails to Sign Transaction: Clarity Type: 48 (v7.0.4) and Generic Error (v6.13.0)

[bmteo1]

Description

When generating a transaction hex (txHex) using makeUnsignedContractCall from @stacks/transactions and sending it to Leather Wallet for signing, we encounter two distinct issues depending on the library version:

• Version 7.0.4 (latest at the time): The Leather popup opens but displays "DeserializationError: Cannot recognize Clarity Type: 48", and the "Confirm" button is not clickable.
• Version 6.13.0: The popup opens, but signing fails with a generic error { "jsonrpc": "2.0", "id": "...", "error": {} }, and no specific error message is provided.

This prevents users from confirming and signing the transaction in a presale widget.

Steps to Reproduce

1. Install @stacks/transactions@7.0.4 (or @stacks/transactions@6.13.0).
2. Create a transaction with makeUnsignedContractCall using these options:

   {
     "contractAddress": "ST2HTPFD9QDXZZGQ2FA4TXKH30PX3YHST0H4JFE0E",
     "contractName": "cat-presale-f3",
     "functionName": "buy-tokens",
     "functionArgs": [{"type": 1, "value": "150000000"}],
     "network": "testnet",
     "senderAddress": "STMN839RM7GAG79Y9574TTZMEKHKKR6RNZC71CDR",
     "fee": "5000",
     "nonce": "85"
   }

[kyranjamie]

@bmteo1 in the latest version of stacks.js, what you've shared causes a type error

[janniks]

For the latest breaking release these have moved to string literal types. e.g. { type: 'uint', value: "10" }
For and easier way of correctly constructing Clarity values I would recommend using the Cl. helper bundle of @stacks/transactions e.g. Cl.uint(10)

[janniks]

Can you share more of your code for serializing? I'm getting this expected error for this when using the latest v7 stacks.js