Smart contract fees paid from another wallet

Question

When using smart contract and creating transaction, current wallet/user pays for fees. Example of transaction:

• burn NFT
• min NFT
• burn native assets

In my situation, my customers have their own wallet (nami #whatever) but is there any chance I can use a company wallet to pay fees instead of them?

Naive idea:

• customers should have some ADA: unfortunately I cannot go forward with it
• granting customers some ADA will allow them to spend them on something else!~

Basically I would have love the idea to have several wallet involve in a single transaction (multisig) but I do not find any relevant solution.

Maybe a different pattern should be think of?

Thanks.

Answer 1

It is definitively possible, provided every paying wallet sign the transaction. To do this with cardano-cli, you have to build the raw transaction as usual, involving the use of different UtxO coming from different wallets.

cardano-cli transaction build ... -> tx.raw

Then, every involved wallet has to sign separately. For this you have to use

cardano-cli transaction witness --tx-body-file tx.raw ... -> tx.wit_x

And finally you have to collect all individually signed tx.wit_x parts and assemble them into a single transaction

cardano-cli transaction assemble --witness-file tx.wit_0 --witness-file tx.wit_1 ...