# Martify marketplace using cardano-serialization-lib

**URL:** <https://forum.cardano.org/t/martify-marketplace-using-cardano-serialization-lib/89037>\
**Category:** Misc Dev Talk\
**Created:** [15 December 2021 12:59 UTC](https://forum.cardano.org/t/martify-marketplace-using-cardano-serialization-lib/89037 "2021-12-15T12:59:55Z")\
**Posts on this page:** 9\
**Page:** 1

<div class="post-metadata">

**Author:** ![Adamuso](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.cardano.org/adamuso/32/25115_2.png) [@Adamuso](https://forum.cardano.org/u/Adamuso)\
**Post date:** [15 December 2021 12:59 UTC](https://forum.cardano.org/t/martify-marketplace-using-cardano-serialization-lib/89037/1 "2021-12-15T12:59:55Z")

</div>

Hi guys,

I try using  
[GitHub - MartifyLabs/Martify: NFT Marketplace on the Cardano Blockchain. Powered by Plutus Smart Contracts](https://github.com/MartifyLabs/Martify)

when I interact with the smart contract using CLI everything works as expected.  
I was able to lock token - offer others to buy it and later I was able to cancel the offer and NFT was back in my wallet.

locking token:

```auto
cardano-cli transaction build \
    --alonzo-era \
    --$testnet \
    --tx-in 1faeef0ce92b02ff90348b4f86f54ac02d6ad6b0270602573130a872dd37af67#0 \
    --tx-in 1faeef0ce92b02ff90348b4f86f54ac02d6ad6b0270602573130a872dd37af67#1 \
    --tx-out "$(cat script.addr) + 1724100 lovelace + 1 $(cat policy/policyID).AdamNFT" \
    --tx-out-datum-hash $(cat dhash) \
    --change-address $(cat payment.addr) \
    --protocol-params-file protocol.json \
    --out-file tx.02 

```

unlocking token:

```auto
cardano-cli transaction build \
    --alonzo-era \
    --$testnet \
    --tx-in d10fcf51e2bc75dd499ff747bfb8f4112e75ced61c598711a00554d08dc930ed#0 \
    --tx-in d10fcf51e2bc75dd499ff747bfb8f4112e75ced61c598711a00554d08dc930ed#1 \
    --tx-in-script-file market.plutus \
    --tx-in-datum-file datum-f9160cfb676909cbd6a6a9bdd7868abd1e3b988fd32ceee05b95246d-AdamNFT.json \
    --tx-in-redeemer-file close.json \
    --required-signer payment.skey \
    --tx-in-collateral d10fcf51e2bc75dd499ff747bfb8f4112e75ced61c598711a00554d08dc930ed#0 \
    --tx-out "$(cat payment.addr) + 1724100 lovelace + 1 f9160cfb676909cbd6a6a9bdd7868abd1e3b988fd32ceee05b95246d.AdamNFT" \
    --change-address $(cat payment.addr) \
    --protocol-params-file protocol.json \
    --out-file unlock-body.02

```

After signing and submitting transaction everything works as expected.

When I try to do lock and cancel using cardano-serialization-lib and hosky code  
[HOSKYSWAP.Validator/hosky-swap-ui-prototype at master · ADAPhilippines/HOSKYSWAP.Validator · GitHub](https://github.com/ADAPhilippines/HOSKYSWAP.Validator/tree/master/hosky-swap-ui-prototype)

```auto
import { Value, TransactionUnspentOutput, BigNum, Vkeywitnesses, PlutusData, Ed25519KeyHash, BaseAddress, Redeemer, PlutusScripts, TransactionBuilder, Address, TransactionOutput } from './custom_modules/@emurgo/cardano-serialization-lib-browser';
import CardanoLoader from './CardanoLoader';
import CardanoProtocolParameters from './Types/CardanoProtocolParam';
import { contractCbor } from "./contract";
import { languageViews } from './languageViews'; import { CoinSelection, setCardanoSerializationLib as setCoinSelectionCardanoSerializationLib } from './coinSelection';
import { PlutusDataObject } from './Types/PlutusDataObject';
import { PlutusField, PlutusFieldType } from './Types/PlutusField';

const BLOCKFROST_PROJECT_ID = "";
const CardanoSerializationLib = async () => {
    return await import("./custom_modules/@emurgo/cardano-serialization-lib-browser/cardano_serialization_lib");
}

const GetWalletAddressAsync = async () => (await window.cardano.getUsedAddresses())[0];
const toHex = (bytes: Uint8Array) => Buffer.from(bytes).toString("hex");
const fromHex = (hex: string) => Buffer.from(hex, "hex");
const toByteArray = (name: string) => Buffer.from(name, "utf8");

const toBigNum = async (value: any) => {
    let Cardano = await CardanoSerializationLib();
    return Cardano?.BigNum.from_str(value.toString()) as BigNum;
}

let btnOffer: HTMLButtonElement;
let btnCancel: HTMLButtonElement;
const policyId = "26e3d767b97e9b61f3bfc294b84b67f6a569aae89666f239eceb7466"
const askingPrice = "5000000";
//const assetName = "StressTestCol04294"
// const scriptTxId = "b77f268a3c55f4919ef1d34be6139ae70c07efe024e3f2d5135b839f14e9fc04"
// const scriptTxIndex = 0
// const amountToTransfer = "2000000"
const assetName = "StressTestCol04256"
const scriptTxId = "1cf640e2672a581a780636c546423f9b10ddb3661d6eb065994e0619a062af24"
const scriptTxIndex = 0
const amountToTransfer = "3000000"
const assetNameInHex = toHex(toByteArray(assetName));

async function Main() {
    await CardanoLoader.LoadAsync();
    btnOffer = document.getElementById("btnOffer") as HTMLButtonElement;
    btnCancel = document.getElementById("btnCancel") as HTMLButtonElement;

    btnOffer.addEventListener("click", OfferToken);
    btnCancel.addEventListener("click", CancelOffer);
}

async function OfferToken() {
    await BuildOfferTxAsync();
}

async function CancelOffer() {
    await CancelOfferTxAsync();
}

async function BuildOfferTxAsync() {
    let Cardano = await CardanoSerializationLib();
    if (Cardano !== null) {
        setCoinSelectionCardanoSerializationLib(Cardano);
        const protocolParameters = await GetProtocolProtocolParamsAsync();
        CoinSelection.setProtocolParameters(
            protocolParameters.min_utxo.toString(),
            protocolParameters.min_fee_a.toString(),
            protocolParameters.min_fee_b.toString(),
            protocolParameters.max_tx_size.toString()
        );

        if (!await window.cardano.isEnabled()) await window.cardano.enable();
        const txBuilder = await CreateTransactionBuilderAsync() as TransactionBuilder;
        const selfAddress = Cardano.Address.from_bytes(fromHex(await GetWalletAddressAsync()));
        const baseAddress = Cardano.BaseAddress.from_address(selfAddress) as BaseAddress;
        const pkh = toHex(baseAddress.payment_cred().to_keyhash()?.to_bytes() as Uint8Array);

        const transactionWitnessSet = Cardano.TransactionWitnessSet.new();
        const hoskyDatumObject = OfferDatum(pkh, askingPrice, policyId, assetName) as PlutusDataObject;
        const datumHash = Cardano.hash_plutus_data(await ToPlutusData(hoskyDatumObject) as PlutusData);

        console.log("datumHash", toHex(datumHash.to_bytes()));
        console.log("pkh", pkh);
        console.log("value", (await GetContractOutput())?.coin().to_str());

        const contractOutput = Cardano.TransactionOutput.new(
            await ContractAddress() as Address,
            await GetContractOutput() as Value
        );
        contractOutput.set_data_hash(datumHash);
        const transactionOutputs = Cardano.TransactionOutputs.new();
        transactionOutputs.add(contractOutput);

        const utxos = await window.cardano.getUtxos();
        const csResult = CoinSelection.randomImprove(
            utxos.map(utxo => Cardano?.TransactionUnspentOutput.from_bytes(fromHex(utxo)) as TransactionUnspentOutput),
            transactionOutputs,
            8
        );

        csResult.inputs.forEach((utxo) => {
            txBuilder.add_input(
                utxo.output().address(),
                utxo.input(),
                utxo.output().amount()
            );
        });

        txBuilder.add_output(contractOutput);
        txBuilder.add_change_if_needed(selfAddress);
        const txBody = txBuilder.build();

        const transaction = Cardano.Transaction.new(
            Cardano.TransactionBody.from_bytes(txBody.to_bytes()),
            Cardano.TransactionWitnessSet.from_bytes(
                transactionWitnessSet.to_bytes()
            )
        );

        const serializedTx = toHex(transaction.to_bytes());

        const txVkeyWitnesses = await window.cardano.signTx(serializedTx, true);

        let signedtxVkeyWitnesses = Cardano.TransactionWitnessSet.from_bytes(
            fromHex(txVkeyWitnesses)
        );

        transactionWitnessSet.set_vkeys(signedtxVkeyWitnesses.vkeys() as Vkeywitnesses);

        const signedTx = Cardano.Transaction.new(
            Cardano.TransactionBody.from_bytes(txBody.to_bytes()),
            Cardano.TransactionWitnessSet.from_bytes(
                transactionWitnessSet.to_bytes()
            )
        );

        console.log("full tx size", signedTx.to_bytes().length);
        console.log("datumObj", hoskyDatumObject);
        const txHash = await window.cardano.submitTx(toHex(signedTx.to_bytes()));
        console.log(txHash);
    }
}

async function CancelOfferTxAsync() {
    let Cardano = await CardanoSerializationLib();
    if (Cardano !== null) {

        setCoinSelectionCardanoSerializationLib(Cardano);
        const protocolParameters = await GetProtocolProtocolParamsAsync();
        CoinSelection.setProtocolParameters(
            protocolParameters.min_utxo.toString(),
            protocolParameters.min_fee_a.toString(),
            protocolParameters.min_fee_b.toString(),
            protocolParameters.max_tx_size.toString()
        );

        const txBuilder = await CreateTransactionBuilderAsync() as TransactionBuilder;
        const transactionWitnessSet = Cardano.TransactionWitnessSet.new();

        const selfAddress = Cardano.Address.from_bytes(fromHex(await GetWalletAddressAsync()));
        const baseAddress = Cardano.BaseAddress.from_address(selfAddress) as BaseAddress;
        console.log(`selfAddress: ${selfAddress.to_bech32()}`);
        // const pkh = "3e4a2ec70fcef9e54c437a173714d1f82b96242379816bea3dd387dd";
        const pkh = toHex(baseAddress.payment_cred().to_keyhash()?.to_bytes() as Uint8Array);
        console.log(`pkh: ${pkh}`)
        const scriptUtxo = Cardano.TransactionUnspentOutput.new(
             Cardano.TransactionInput.new(
                Cardano.TransactionHash.from_bytes(fromHex(scriptTxId)), scriptTxIndex
             ),
             Cardano.TransactionOutput.new(
                await ContractAddress() as Address,
                await GetContractOutput() as Value
            )
        );
        const utxos = (await window.cardano.getUtxos()).map((utxo) =>
             Cardano.TransactionUnspentOutput.from_bytes(fromHex(utxo))
        );
        const outputs: TransactionOutput[] = [
            Cardano.TransactionOutput.new(
                selfAddress, 
                await GetContractOutput() as Value
            )
        ];
        const transactionOutputs = Cardano.TransactionOutputs.new();
        outputs.forEach(output => transactionOutputs.add(output));
        const csResult = CoinSelection.randomImprove(
            utxos,
            transactionOutputs,
            8,
            [scriptUtxo]
        );

        csResult.inputs.forEach((utxo) => {
            console.log(`output address: ${utxo.output().address().to_bech32()}`)
            console.log(`input: txId ${toHex(utxo.input().transaction_id().to_bytes())} txIndex ${utxo.input().index()}`)
            console.log(`output amount: ${utxo.output().amount().coin().to_str()} lovelace, other len: ${utxo.output().amount().multiasset()?.len()}`)
            txBuilder.add_input(
                utxo.output().address(),
                utxo.input(),
                utxo.output().amount()
            );
        });

        const scriptInputIndex = txBuilder.index_of_input(scriptUtxo.input());

        outputs.forEach(output => txBuilder.add_output(output));
        const requiredSigners = Cardano.Ed25519KeyHashes.new();
        requiredSigners.add(baseAddress.payment_cred().to_keyhash() as Ed25519KeyHash);
        txBuilder.set_required_signers(requiredSigners);

        const datumObj = OfferDatum(pkh, askingPrice, policyId, assetName);
        const datum = await ToPlutusData(datumObj as PlutusDataObject) as PlutusData;
        const datumHash = Cardano.hash_plutus_data(datum);
        console.log("datumHash", toHex(datumHash.to_bytes()));

        const datumList = Cardano.PlutusList.new();
        datumList.add(datum);

        const redeemers = Cardano.Redeemers.new();
        // not passing datum because close.json content is {"constructor":2,"fields":[]}
        redeemers.add(await SimpleRedeemer(scriptInputIndex) as Redeemer);

        txBuilder.set_plutus_scripts(await ContractScript() as PlutusScripts);
        txBuilder.set_plutus_data(datumList);
        txBuilder.set_redeemers(redeemers);

        transactionWitnessSet.set_plutus_scripts(await ContractScript() as PlutusScripts);
        transactionWitnessSet.set_plutus_data(datumList);
        transactionWitnessSet.set_redeemers(redeemers);

        const collateralUnspentTransactions = (await GetCollateralUnspentTransactionOutputAsync()) as TransactionUnspentOutput[];
        const collateralInputs = Cardano.TransactionInputs.new();
        collateralUnspentTransactions.forEach(c => collateralInputs.add(c.input()));
        txBuilder.set_collateral(collateralInputs);
        txBuilder.add_change_if_needed(selfAddress);

        const txBody = txBuilder.build();

        const transaction = Cardano.Transaction.new(
            Cardano.TransactionBody.from_bytes(txBody.to_bytes()),
            transactionWitnessSet
        );

        const serializedTx = toHex(transaction.to_bytes());

        const txVkeyWitnesses = await window.cardano.signTx(serializedTx, true);

        let signedtxVkeyWitnesses = Cardano.TransactionWitnessSet.from_bytes(
            fromHex(txVkeyWitnesses)
        );

        transactionWitnessSet.set_vkeys(signedtxVkeyWitnesses.vkeys() as Vkeywitnesses);

        const signedTx = Cardano.Transaction.new(
            Cardano.TransactionBody.from_bytes(txBody.to_bytes()),
            transactionWitnessSet
            // Cardano.TransactionWitnessSet.from_bytes(
            // transactionWitnessSet.to_bytes()
            // )
        );

        console.log("Full Tx Size", signedTx.to_bytes().length);
        let result = await window.cardano.submitTx(toHex(signedTx.to_bytes()));
        console.log("tx submitted", result);
    }
}

async function GetProtocolProtocolParamsAsync(): Promise<CardanoProtocolParameters> {
    let protocolParamsResult = await fetch("https://cardano-testnet.blockfrost.io/api/v0/epochs/latest/parameters", {
        "headers": {
            "project_id": BLOCKFROST_PROJECT_ID
        }
    });
    return await protocolParamsResult.json();
}

const GetContractOutput = async () => {
    let Cardano = await CardanoSerializationLib();
    if (Cardano !== null) {
        return AssetValue(
                await toBigNum(amountToTransfer),
                policyId,
                assetNameInHex,
                await toBigNum("1")
            );
    }
}

const AssetValue = async (lovelace: BigNum, policyIdHex: string, assetNameHex: string, amount: BigNum) => {
    let Cardano = await CardanoSerializationLib();
    if (Cardano !== null) {
        const assetVal = Cardano.Value.new(lovelace);
        const assetMA = Cardano.MultiAsset.new();
        const asset = Cardano.Assets.new();

        asset.insert(
            Cardano.AssetName.new(fromHex(assetNameHex)),
            amount
        );

        assetMA.insert(
            Cardano.ScriptHash.from_bytes(fromHex(policyIdHex)),
            asset
        );

        assetVal.set_multiasset(assetMA)
        return assetVal;
    }
}

const ToPlutusData = async (plutusDataObj: PlutusDataObject) => {
    let Cardano = await CardanoSerializationLib();
    if (Cardano !== null) {

        const datumFields = Cardano.PlutusList.new();
        plutusDataObj.Fields.sort((a, b) => a.Index - b.Index);
        plutusDataObj.Fields.forEach(f => {
            if (Cardano === null) return;
            switch (f.Type) {
                case PlutusFieldType.Integer:
                    datumFields.add(Cardano.PlutusData.new_integer(Cardano.BigInt.from_str(f.Value.toString())));
                    break;
                // case PlutusFieldType.Data:
                // datumFields.add(ToPlutusData(f.Value) as PlutusData);
                case PlutusFieldType.Bytes:
                    datumFields.add(Cardano.PlutusData.new_bytes(f.Value));
            }
        })

        return Cardano.PlutusData.new_constr_plutus_data(
            Cardano.ConstrPlutusData.new(
                Cardano.Int.new_i32(plutusDataObj.ConstructorIndex),
                datumFields
            )
        );
    }
}

const OfferDatum = (pkh: string, price: string, policyId: string, assetName: string) => {
    let Cardano = CardanoSerializationLib();
    if (Cardano !== null) {

        const offerDatum = new PlutusDataObject(0);
        offerDatum.Fields = [
            {
                Index: 0,
                Type: PlutusFieldType.Bytes,
                Key: "pkh",
                Value: fromHex(pkh)
            } as PlutusField,
            {
                Index: 0,
                Type: PlutusFieldType.Integer,
                Key: "price",
                Value: price
            } as PlutusField,
            {
                Index: 0,
                Type: PlutusFieldType.Bytes,
                Key: "policyId",
                Value: toByteArray(policyId)
            } as PlutusField,
            {
                Index: 0,
                Type: PlutusFieldType.Bytes,
                Key: "assetName",
                Value: toByteArray(assetName)
            } as PlutusField,
            
        ];

        return offerDatum;
    }
}

const CreateTransactionBuilderAsync = async () => {
    let Cardano = await CardanoSerializationLib();
    if (Cardano !== null) {
        let protocolParams = await GetProtocolProtocolParamsAsync();
        const txBuilder = Cardano.TransactionBuilder.new(
            Cardano.LinearFee.new(
                await toBigNum(protocolParams.min_fee_a),
                await toBigNum(protocolParams.min_fee_b)
            ),
            await toBigNum("1000000"),
            await toBigNum("500000000"),
            await toBigNum("2000000"),
            parseInt("5000"),
            16384,
            5.77e-2,
            7.21e-5,
            Cardano.LanguageViews.new(fromHex(languageViews))
        );
        return txBuilder;
    }
}

const SimpleRedeemer = async (index: number) => {
    let Cardano = await CardanoSerializationLib();
    if (Cardano !== null) {
        //close.json - {"constructor":2,"fields":[]} - this is why I pyt new_i32(2), maybe I'm wrong here
        const redeemerData = Cardano.PlutusData.new_constr_plutus_data(
            Cardano.ConstrPlutusData.new(
                Cardano.Int.new_i32(2),
                Cardano.PlutusList.new()
            )
        );

        const r = Cardano.Redeemer.new(
            Cardano.RedeemerTag.new_spend(),
            await toBigNum(index),
            redeemerData,
            Cardano.ExUnits.new(
                Cardano.BigNum.from_str("1754991"),
                Cardano.BigNum.from_str("652356532")
            )
        )

        return r;
    }
}

const ContractScript = async () => {
    let Cardano = await CardanoSerializationLib();
    if (Cardano !== null) {
        const scripts = Cardano.PlutusScripts.new();
        scripts.add(Cardano.PlutusScript.new(fromHex(contractCbor)));
        return scripts;
    }
};

const GetCollateralUnspentTransactionOutputAsync = async () => {
    let Cardano = await CardanoSerializationLib();
    if (Cardano !== null) {
        const utxosHex = await window.cardano.getCollateral();
        let utxos = utxosHex.map((utxoHex: string) => Cardano?.TransactionUnspentOutput.from_bytes(fromHex(utxoHex) ?? null));
        utxos = utxos.filter((utxo) => utxo !== undefined);
        return utxos as TransactionUnspentOutput[];
    }
};

const ContractAddress = async () => {
    let Cardano = await CardanoSerializationLib();
    if (Cardano !== null) {
        return Cardano.Address.from_bech32("addr_test1wrgd386qdtskfe5uhtk3ur9yx4mnjr5qfn4w0n6uhc9zmwq2qa6n4")
    }
}

document.onreadystatechange = async () => {
    if (document.readyState === "complete") await Main();
};

```

I’m getting exception:

```auto
transaction submit error ShelleyTxValidationError ShelleyBasedEraAlonzo (ApplyTxError 
[UtxowFailure (NonOutputSupplimentaryDatums (fromList [SafeHash \"8ac77ecbddbc22497349be7ef08ea61bccc57733b588548ebe1d8c6c0a68f9c8\"]) (fromList [])),
 UtxowFailure (ExtraRedeemers [RdmrPtr Spend 0]),UtxowFailure (WrappedShelleyEraFailure (MissingScriptWitnessesUTXOW (fromList [ScriptHash \"d0d89f406ae164e69cbaed1e0ca43577390e804ceae7cf5cbe0a2db8\"]))),
 UtxowFailure (WrappedShelleyEraFailure (UtxoFailure (UtxosFailure (CollectErrors [NoWitness (ScriptHash \"d0d89f406ae164e69cbaed1e0ca43577390e804ceae7cf5cbe0a2db8\")]))))])"

```

Any idea why I cannot unlock and why it is complaining that I’m missing signature?

---

<div class="post-metadata">

**Author:** ![Adamuso](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.cardano.org/adamuso/32/25115_2.png) [@Adamuso](https://forum.cardano.org/u/Adamuso)\
**Post date:** [15 December 2021 16:38 UTC](https://forum.cardano.org/t/martify-marketplace-using-cardano-serialization-lib/89037/2 "2021-12-15T16:38:43Z")

</div>

I spoke with Leni from the project and he told me to check what is the cbor for smart contract when transaction is executed using cli. I went to [test.cardanoscan.io](http://test.cardanoscan.io) and checked  
[Transaction 17862d2cf34f660aef46a3bca3aff8ba13b0e18769b85feb41cb691ad7e38c70 - Cardanoscan](https://testnet.cardanoscan.io/transaction/17862d2cf34f660aef46a3bca3aff8ba13b0e18769b85feb41cb691ad7e38c70?tab=contracts)

apparently the bytecode was different than the one in market.plutus file. In the file the cboxHex had some extra bytes “591561” that were not present on the cardanoscan.  
Once I took the bytecode from cardanoscan and used it with cardano-serialization-lib I was able to cancel sale.

---

<div class="post-metadata">

**Author:** ![Alicia](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.cardano.org/alicia/32/37748_2.png) [@Alicia](https://forum.cardano.org/u/Alicia)\
**Post date:** [17 December 2021 14:56 UTC](https://forum.cardano.org/t/martify-marketplace-using-cardano-serialization-lib/89037/3 "2021-12-17T14:56:53Z")

</div>

> [@Adamuso](#):
>
> ```auto
> const pkh = toHex(baseAddress.payment_cred().to_keyhash()?.to_bytes() as Uint8Array);
> 
> ```

Are you sure the pkh is correctly used? 🙂 … i am just at that step

---

<div class="post-metadata">

**Author:** ![Adamuso](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.cardano.org/adamuso/32/25115_2.png) [@Adamuso](https://forum.cardano.org/u/Adamuso)\
**Post date:** [20 December 2021 08:48 UTC](https://forum.cardano.org/t/martify-marketplace-using-cardano-serialization-lib/89037/5 "2021-12-20T08:48:06Z")

</div>

yes, this is public key hash of the seller. This value has to be passed to datum when used for cancellation, updating offer and eventually by other party that wants to buy needs to pass public key hash of the owner of the NFT. It is validated by onchain code.

---

<div class="post-metadata">

**Author:** ![Alicia](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.cardano.org/alicia/32/37748_2.png) [@Alicia](https://forum.cardano.org/u/Alicia)\
**Post date:** [23 December 2021 02:23 UTC](https://forum.cardano.org/t/martify-marketplace-using-cardano-serialization-lib/89037/6 "2021-12-23T02:23:14Z")

</div>

I did not underestand what did you do for making it work, the extra bytes in the cborHex where did they came from? did the Cardano Serialization Lib put them? or did the haskell compiler added them?

---

<div class="post-metadata">

**Author:** ![TheIT\_Guy](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.cardano.org/theit_guy/32/24591_2.png) [@TheIT\_Guy](https://forum.cardano.org/u/TheIT_Guy)\
**Post date:** [27 April 2022 22:55 UTC](https://forum.cardano.org/t/martify-marketplace-using-cardano-serialization-lib/89037/7 "2022-04-27T22:55:19Z")

</div>

Hi @Adamuso ,

I have just started the plutus development and saw your thread on this.

I am struggling with creating the datum , in the instructions it is written to do :l src/SerialiseJSON.hs`; then run`testR`or`testD.

testR works fine for me but testD is not showing anything. Do you know how can I create the datum

---

<div class="post-metadata">

**Author:** ![nmaddp1995](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.cardano.org/nmaddp1995/32/55845_2.png) [@nmaddp1995](https://forum.cardano.org/u/nmaddp1995)\
**Post date:** [6 July 2022 07:22 UTC](https://forum.cardano.org/t/martify-marketplace-using-cardano-serialization-lib/89037/9 "2022-07-06T07:22:00Z")

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@Adamuso Hi, do you find out how to fix it, and can you tell me what instructions are you following to do that sample?

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**Author:** ![AlainMgz](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.cardano.org/alainmgz/32/44915_2.png) [@AlainMgz](https://forum.cardano.org/u/AlainMgz)\
**Post date:** [14 August 2022 16:18 UTC](https://forum.cardano.org/t/martify-marketplace-using-cardano-serialization-lib/89037/10 "2022-08-14T16:18:49Z")

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Hello @TheIT_Guy and @nmaddp1995,

Thanks for using Martify code! If you’re still having issues feel free to reach out to us on Twitter or join the Discord, [http://linktr.ee/martifylabs](https://t.co/wVVtopavL6)

We’re more active there than on this forum 🙂

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**Author:** ![DuaaAzhar](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.cardano.org/duaaazhar/32/66765_2.png) [@DuaaAzhar](https://forum.cardano.org/u/DuaaAzhar)\
**Post date:** [2 May 2023 06:34 UTC](https://forum.cardano.org/t/martify-marketplace-using-cardano-serialization-lib/89037/11 "2023-05-02T06:34:14Z")

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Hi, @Adamuso Can you please share your buy and sell function of this marketplace. I am badly stuck in redeeming/Buying my NFT from a smart contract. The only related resource about cardano serialization i found was your post. I hope that your buy and sell function can help me out somehow.