You could try [Helios](https://www.npmjs.com/package/@hyperionbt/helios). Here is a guide to building transactions: https://www.hyperion-bt.org/Helios-Book/api/building/index.html The following links will help you define a UTxO containing native assets: * https://www.hyperion-bt.org/Helios-Book/api/reference/utxo.html * https://www.hyperion-bt.org/Helios-Book/api/reference/txoutput.html * https://www.hyperion-bt.org/Helios-Book/api/reference/value.html * https://www.hyperion-bt.org/Helios-Book/api/reference/assets.html * https://www.hyperion-bt.org/Helios-Book/api/reference/mintingpolicyhash.html If you're struggling with using ES imports, then you can try the following import style: ``` import("/path/to/helios.js").then( helios=>{ const tx = new helios.Tx() ... }) ``` Note: Helios is more low-level than Lucid/Mesh because you need to take care of calling the Blockfrost API yourself.