Adding contract owned assets as inputs to transactions

Hello Fuel team!
Let’s say I have a following function:

pub fn checkAssetOwnership(checked_asset: AssetId) -> bool {
    let num_inputs = input_count().as_u64();
    let mut i = 0;
    while i < num_inputs {
        match input_type(i) {
            Input::Coin => {
                let asset_id = input_asset_id(i).unwrap();
                if asset_id == checked_asset {
                    return true;
            _ => {},
        i = i + 1;

Let’s consider that I have another contract which minted an NFT and owns it.
I wish to send a transaction from that contract to another one to check the ownership using the function above (attaching the input). Is there any way of how I can send an Input from a contract address to check the ownership? If it’s not possible, could you please suggest any alternatives (if any) to achieve that.

Thank you!


Hey @Serafim thanks for the question! I’m getting input on the Sway standards team as to how you should go about this.


Please let me know if this answers your question because I have a feeling I’m misunderstanding your question but…

Contracts can utilize std::context::balance_of to retrieve the balance associated with a specific contractid for a given assetid.

For example, you can see how it is implemented in this code snippet: sway/sway-lib-std/src/context.sw at 55140ba8d534a805f9080b7fa4e9ba8fc99e8d31 · FuelLabs/sway · GitHub.

I hope this helps :slight_smile:


Hey @calldelegation! Seems that the answer solves the problem I’ve got, thank you!

For anyone who has the same question as I did, it might be useful to read the following question to understand how balance is stored for contracts and what’s the difference between account balance and contract balance: How to get the balance of an EOA address in sway

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