# Using Bitcore to sign Counterparty transactions?

**URL:** https://forums.counterparty.io/t/using-bitcore-to-sign-counterparty-transactions/2163
**Category:** Development
**Created:** [June 27, 2016, 5:53pm UTC](https://forums.counterparty.io/t/using-bitcore-to-sign-counterparty-transactions/2163 "2016-06-27T17:53:53Z")
**Posts on this page:** 1
**Page:** 1

<div class="post-metadata">

### Author: ![taco\_bell](https://avatars.discourse-cdn.com/v4/letter/t/5f8ce5/32.png) [@taco\_bell](https://forums.counterparty.io/u/taco_bell)
#### Post date: [June 27, 2016, 5:53pm UTC](https://forums.counterparty.io/t/using-bitcore-to-sign-counterparty-transactions/2163/1 "2016-06-27T17:53:54Z")

</div>

I’m trying to use Bitcore to sign a transaction made by CounterParty. I’m getting an error though:

```
hex = "01000000014330a448667526595512e6da39b77d3f3aaa78b82e06176f5f368101e82594f8020000001976a914ad44fd5f413830597f94896600574d68d63e7a1b88acffffffff0336150000000000001976a91443878e562582fc0201cac32258bd696ee1cf40e588ac00000000000000001e6a1c40029655dfedd4425bfba0441cec6ec532ab25d38052c542d3ba5b854dc70000000000001976a914ad44fd5f413830597f94896600574d68d63e7a1b88ac00000000";

tx = new bitcore.Transaction(hex);
tx.sign("KzWsS4UaUaCfUbrtg1k...")

```

Has anyone been able to sign a counterparty transaction with bitcore? How did you achieve it? The error I get is “Invalid state: undefined”