<aside> 💡 This document demonstrates the features of the core API released in March 2021. Nine Chronicles is a serverless game, so there is no central API server, but you can use the GraphQL interface locally by running the client. Currently, NCG (Nine Chronicles Gold) transfer is only available through API, so those who have done NCG transactions will be familiar with it.

</aside>

What's Nine Chronicles?

Nine Chronicles is an online game without servers — like Bitcoin or BitTorrent, the gamers and miners connect to each other to power a distributed game network.

We believe decentralized infrastructure has created new possibilities for online gaming. Just like blockchain ecosystems, communities will be able to powerfully decentralized ostgames that are widely open for creative experimentation. Since these community-powered worlds are open source and perpetual, talented game designers and developers can take over a stagnant world any time and breathe a new life into it. For more information, visit docs.nine-chronicles.com.

Getting started

You must first launch the game launcher to begin — if you haven't gotten started, please visit nine-chronicles.com to join our early access.

After launching the game, open the internet browser and access http://localhost:23061/ui/playground to load the GraphQL playground. In addition to the official client, headless builds can be used. When developing new services, try the steps below with the headless build, which is easier to execute on a server machine like Linux environment.

Accessing agent and shop data from the playground

Let's search the store information through the playground and buy the desired item. Key information in the game can be inquired through query → stateQuery. First, we will obtain the player's avatar address to facilitate the inquiry. This can be queried with an agent query, and then details can be viewed through an avatar query.

The agent's address can be copied from the launcher's login screen or from the bottom right.

query {
  stateQuery {
    agent(address: "0xA116d45d176aeD204a7627A470e87907e57BE6CD") {
      avatarAddresses
    }
    avatar(address:"0x122a60B6a56CC0D23Aad4A07c9E724d49044eB6D") {
      actionPoint
      level
      agentAddress
    }
  }
}

{
  "data": {
    "stateQuery": {
      "agent": {
        "avatarAddresses": [
          "0x122a60B6a56CC0D23Aad4A07c9E724d49044eB6D"
        ]
      },
      "avatar": {
        "actionPoint": 100,
        "level": 158,
        "agentAddress": "0xA116d45d176aeD204a7627A470e87907e57BE6CD"
      }
    }
  },
  "extensions": {}
}

In the game, there is a difference between the properties managed by the agent and the properties managed by the avatar. For example, gold is managed by the agent, and equipment is managed by the avatar. Since product purchasing is a transaction between avatars, we will need to use our avatar address for this action.

Ok, then let's get the store information. If you use the playground's SCHEMA tab, you can check the information of the data that can be imported, and the auto-complete function is also provided so you can conveniently check your query. In this demo, let's search for foods less than 100 Gold.

query {
  stateQuery { 
    shop {
      products(itemSubType: FOOD, maximumPrice: 100) {
        itemUsable {
          id
          itemId
        }
        price
        sellerAgentAddress
        sellerAvatarAddress
        productId
      }
    }
  }
}

{
  "data": {
    "stateQuery": {
      "shop": {
        "products": [
          {
            "itemUsable": {
              "id": 201005,
              "itemId": "d19ca62e-3504-4ca7-83db-f0041ff47706"
            },
            "price": "20 NCG",
            "sellerAgentAddress": "0x2609F8e941caB431F68Ec2772D963F5006341C7c",
            "sellerAvatarAddress": "0x16741aa2387ad785d45D154293B7dC98C3A8e084",
            "productId": "13e1de91-9271-40bb-86b7-c53140b62838"
          },
          {
            "itemUsable": {
              "id": 201011,
              "itemId": "40fb0509-7f63-4815-a51d-3a976ea17ded"
            },
            "price": "28 NCG",
            "sellerAgentAddress": "0x3a3aDe342Dd061cCb1B7b4a011d7648fb509e441",
            "sellerAvatarAddress": "0xB781D43C5258e480f202EAEd4811ee05f680F797",
            "productId": "5e699ecb-5055-4233-a229-0d309a74e387"
          }
        ]
      }
    }
  },
  "extensions": {}
}

Create a buy action and check if the transaction id has been incorporated

By using GraphQL API, you can make transactions by executing mutations. For example, let's buy an item by entering the required information in the buy query. Before executing, you need to log in to the game.

mutation {
  action {
    buy(
      buyerAvatarAddress:"0x122a60B6a56CC0D23Aad4A07c9E724d49044eB6D",
      sellerAgentAddress: "0x2609F8e941caB431F68Ec2772D963F5006341C7c",
      sellerAvatarAddress: "0x16741aa2387ad785d45D154293B7dC98C3A8e084",
      productId: "13e1de91-9271-40bb-86b7-c53140b62838")
  }
}