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Meta data

If you haven't set up your TradableAsset Pravda program yet, read Tradable Asset Standard first.

The integration with Expload Auction also requires a meta-server, providing Expload Auction with all necessary asset data - names, descriptions, preview pictures, etc.

Meta data structure

Meta data has the following format:

    "name": <itemName>,
    "description": <itemShortDescription>,
    "pictureUrl": <itemPictureURL>,
    "previewPictureUrl": <itemPreviewPictureURL>,
    "tags": <tagsData>

name - asset name. For example, "Toy Sword".
description - short asset description. For example, "Give it back to me, I'll cal my mom!".
pictureUrl - link to asset's picture. .png, transparent background, square orientation is preferred. Maximal size - 512px x 512 px.
previewPictureUrl - link to a smaller (preview) asset picture. Requirements are the same as for pictureUrl.
tags - dictionary with other asset data. For example:

    "name": "Toy Sword",
    "description": "Give it back to me, I'll cal my mom!",
    "pictureUrl" : "",
    "previewPictureUrl" : "",
    "tags" :  {
        "rarity": ["legendary"],
        "class": ["warrior", "paladin", "berserk"]

Data in tags can be used for searching and filtering assets on Expload Auction.

As previously described, each asset has two identificators having an in-game meaning - classId and instanceId. Meta-server should provide asset data using any of those two identificators. classId meta data will be shown in auction asset tabs, instanceId meta data - when choosing specific auction lots and inventory items. Another words, classId is a more general information then instanceId. Data shown in class meta shouldn't be duplicated in instance meta: empty instance data fields will be replaced by class data fields and non-empty instance data fields will override class data fields.


The game should have a meta-server which has a public API for class- and instance-meta. There is an implementation example written in C#.

Program setup

When your meta-server is ready it is necessary to add information about it to your TradableAsset Pravda program. Modify methods GetClassIdMeta and GetInstanceIdMeta so that when those methods are given a classId or an instanceId, they return a link to the needed data on your meta server.

After modifying the code you have to either deploy your program, or, if you've done it before, use following commands:

# For custom implementations this will
# only work for development using PravdaProgramTemplate:

dotnet publish -c Update


Если вы выполнили все предыдущие шаги, и представитель Expload присвоил вашей игре GameId, то вы готовы к работе с аукционом!

Ваша игра будет отображаться в аукционе в приложении Expload. Вы также можете сделать дополнительный интерфейс аукциона внутри своей игры, используя исходный код аукциона.