# Need help understanding the jpg.store tx metadata

**URL:** <https://forum.cardano.org/t/need-help-understanding-the-jpg-store-tx-metadata/104135>\
**Category:** Transaction Metadata\
**Created:** [2 July 2022 20:10 UTC](https://forum.cardano.org/t/need-help-understanding-the-jpg-store-tx-metadata/104135 "2022-07-02T20:10:05Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Sirez](https://avatars.discourse-cdn.com/v4/letter/s/c0e974/32.png) [@Sirez](https://forum.cardano.org/u/Sirez)\
**Post date:** [2 July 2022 20:10 UTC](https://forum.cardano.org/t/need-help-understanding-the-jpg-store-tx-metadata/104135/1 "2022-07-02T20:10:05Z")

</div>

Hi,

I hope this is the right category for this type op question.

I’m trying to understand the transacrtion meta data of jpg store.

This transaction [Transaction 71c8f5a9d42aa74e984938a8c2e2ac4f05eb469cd47ca4df181a2f5524933bb4 - Cardanoscan](https://cardanoscan.io/transaction/71c8f5a9d42aa74e984938a8c2e2ac4f05eb469cd47ca4df181a2f5524933bb4?tab=metadata) f.e. is the listing of an asset for 239 ADA. But where is this information stored in the meta data? Do I have to decrypt the hashes in some way?

Hope someone can help me to understand this 😃

Kind regards

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<div class="post-metadata">

**Author:** ![HeptaSean](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.cardano.org/heptasean/32/82306_2.png) [@HeptaSean](https://forum.cardano.org/u/HeptaSean)\
**Post date:** [2 July 2022 21:12 UTC](https://forum.cardano.org/t/need-help-understanding-the-jpg-store-tx-metadata/104135/2 "2022-07-02T21:12:00Z")

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Looking at another sell on the same contract:  
Offer: [https://cardanoscan.io/transaction/102a6d8c0c5f91bb42f9470ddff0d3dc6b6a5c780ee44009cd6bd854ad6adda5](https://cardanoscan.io/transaction/102a6d8c0c5f91bb42f9470ddff0d3dc6b6a5c780ee44009cd6bd854ad6adda5)  
Sell: [https://cardanoscan.io/transaction/7a6f53feed7d421ea487a84a6ab7fcc8f5467971cea55b45005f173dfaeccbf9](https://cardanoscan.io/transaction/7a6f53feed7d421ea487a84a6ab7fcc8f5467971cea55b45005f173dfaeccbf9)  
The strings in the metadata array of the offer are exactly the datum given to the smart contract later in the sell transaction.

According to [https://github.com/jpg-store/contract-v2#specification](https://github.com/jpg-store/contract-v2#specification), this should contain your public key hash, the asset, and the payout.

I tried to decode the things in your transaction with [https://cbor.me/](https://cbor.me/?bytes=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) and it gives me:

```auto
121([h'D536801A890A41B4CCCC9AD28F9E90010A34DD4B0C45F69823988207',
[121([121([121([h'2A6728F4DED4DDF1E7097E94B7A3303FD3B6433F6A21B41174BC7440']),
121([121([121([h'21BD9B422CE832842B1CFA9917C2C7CAB40C27A589B1E9E4F75EC699'])])])]), {h'': 121([0, {h'': 11950000}])}]),
121([121([121([h'70E60F3B5EA7153E0ACC7A803E4401D44B8ED1BAE1C7BAAAD1A62A72']),
121([121([121([h'1E78AAE7C90CC36D624F7B3BB6D86B52696DC84E490F343EBA89005F'])])])]), {h'': 121([0, {h'': 4780000}])}]),
121([121([121([h'D536801A890A41B4CCCC9AD28F9E90010A34DD4B0C45F69823988207']),
121([121([121([h'CDFEC174B3189F5CCB704F9184A3F1A5508AF0FF82699A8905A83FD6'])])])]), {h'': 121([0, {h'': 222270000}])}])]])

```

Could be an encoding for 222.27 ADA shall go to you, 11.95 ADA shall go as royalties to the creator, and 4.78 ADA are fees, which would exactly sum up to your 239 ADA.

(jpg.store is actually quite good in including the complete datum in the offer transaction. When I was looking at swap requests in SundaeSwap, there were no metadata other than the string “swap request”. They seem to manage those things off-chain, which also means that they are not really secured by a smart contract.)

EDIT: The addresses that are given in those datums can actually be found on Cardanoscan if you prepend `01` (for the type of address) and then concatenate the payment and the stake hash (converted to lower-case, since Cardanoscan can only handle that):  
[https://cardanoscan.io/address/012a6728f4ded4ddf1e7097e94b7a3303fd3b6433f6a21b41174bc744021bd9b422ce832842b1cfa9917c2c7cab40c27a589b1e9e4f75ec699](https://cardanoscan.io/address/012a6728f4ded4ddf1e7097e94b7a3303fd3b6433f6a21b41174bc744021bd9b422ce832842b1cfa9917c2c7cab40c27a589b1e9e4f75ec699) is the one set to receive 11.95 ADA and it receives a lot of mid-size ADA values in transactions, where BlockOwls are involved, which fits a royalty address.  
[https://cardanoscan.io/address/0170e60f3b5ea7153e0acc7a803e4401d44b8ed1bae1c7baaad1a62a721e78aae7c90cc36d624f7b3bb6d86b52696dc84e490f343eba89005f](https://cardanoscan.io/address/0170e60f3b5ea7153e0acc7a803e4401d44b8ed1bae1c7baaad1a62a721e78aae7c90cc36d624f7b3bb6d86b52696dc84e490f343eba89005f) is the one set to receive 4.78 ADA and it receives a lot of such small transactions. It is obviously an address of jpg.store for collecting fees.  
[https://cardanoscan.io/address/01d536801a890a41b4cccc9ad28f9e90010a34dd4b0c45f69823988207cdfec174b3189f5ccb704f9184a3f1a5508af0ff82699a8905a83fd6](https://cardanoscan.io/address/01d536801a890a41b4cccc9ad28f9e90010a34dd4b0c45f69823988207cdfec174b3189f5ccb704f9184a3f1a5508af0ff82699a8905a83fd6) is your address set to receive 222.27 ADA.

The asset itself does not seem to be encoded in the datum. Maybe, it is another version of the contract.

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<div class="post-metadata">

**Author:** ![HeptaSean](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.cardano.org/heptasean/32/82306_2.png) [@HeptaSean](https://forum.cardano.org/u/HeptaSean)\
**Post date:** [2 July 2022 22:04 UTC](https://forum.cardano.org/t/need-help-understanding-the-jpg-store-tx-metadata/104135/3 "2022-07-02T22:04:29Z")

</div>

This analysis makes me think: It should be possible to manually construct and submit an offer without fees and royalties.

Would be interesting if it appears on their web interface and can be accepted by anyone through it.

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<div class="post-metadata">

**Author:** ![Sirez](https://avatars.discourse-cdn.com/v4/letter/s/c0e974/32.png) [@Sirez](https://forum.cardano.org/u/Sirez)\
**Post date:** [6 July 2022 20:08 UTC](https://forum.cardano.org/t/need-help-understanding-the-jpg-store-tx-metadata/104135/4 "2022-07-06T20:08:08Z")

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Thank you so much for the detailed answer!

You went beyond my expectations 😃

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<div class="post-metadata">

**Author:** ![zing-rsa](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.cardano.org/zing-rsa/32/82727_2.png) [@zing-rsa](https://forum.cardano.org/u/zing-rsa)\
**Post date:** [23 March 2025 20:08 UTC](https://forum.cardano.org/t/need-help-understanding-the-jpg-store-tx-metadata/104135/5 "2025-03-23T20:08:26Z")

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@HeptaSean, not sure how much context you have around this metadata exactly, but I thought I’d try my luck. I’m trying to figure out what the `30` label refers to(seemingly included in all jpg store metadata). In all the linked transactions here I see the value for this label is `1`, however in most recent transactions on jpg store I see it can be `4`, `5` and `6`. Presumably it is a version? Looking through lots of transactions I’ve noticed some patterns, for example;

- where the `30` label has a value of `>=5`, the datum labels start at `50` onwards.
- for values of `<5`, the datum labels start at `0`

I haven’t been able to prove this, but seems like an alright starting point. Perhaps you or someone else can confirm this? thanks
