Introduction

In this guide, we will walk you through the process of creating a dynamic NFT using Space and Time and Chainlink Functions. We will create a SwordNFT that's rating changes based on how the sword is being used in-game. More specifically, gaming telemetry in Space and Time is updated, and fed to the NFT contract using Chainlink Functions.

Here is an example of what the NFT will look like when we're done.

Before we get started, we should answer a couple of important questions.

What is a dynamic NFT (dNFT)?

From a simple view, according to ERC721 (and ERC1155) non-fungible tokens should have a tokenURI function that stores a URL which will return a JSON blob of metadata for a given NFT. That blob usually contains things like a pointer to an image file, NFT name, description, etc. A dNFT is simply an NFT where the metadata for the NFT is designed to change.

But I thought NFTs weren't supposed to change!

There is nothing in ERC721/ERC1155 that says an NFT's metadata cannot change. The idea that an NFT's metadata shouldn't change likely comes from one specific use case involving permanent digital collectibles. While a full discussion on the topic is beyond the scope of this guide, it's important to understand that NFTs can take on many forms, and there is an increasing demand for NFTs that can evolve and/or be leveled up. Also, keep in mind that it's important to think about who (or what) can make changes to an NFT, how those changes can be made, and how long it's possible to make changes.

Overview

For the guide we will go through the following high-level steps:

1. Base Setup & Config
   • Prerequisites
   • Download & install repo
   • Setup env-enc
2. Space and Time Setup
   • Create Table
   • Insert Data
3. Connect SxT to Mumbai via Chainlink Functions
4. Level Up Your SwordNFT

1. Base Setup & Config

❗

Space and Time and Chainlink Functions are both in beta. It's probable that updates will be made to one or both that change how steps in this guide work. You can find us on Discord with questions.

Prerequisites

1. You will need beta access to Space and Time and Chainlink Functions. You can sign up for access to SxT beta here and Chainlink Functions beta here.

2. If you're new to SxT it's recommended that you start first with our SxT Getting Started Guide. If you're new to Chainlink Functions, we recommend you start with their Getting Started Guide. Having a basic understanding of how to connect to SxT and how Chainlink Functions work will set you up for success with this guide.

Setup

1. git clone https://github.com/SxT-Community/SxT-dNFT.git && cd SxT-DNFT
2. npm install
3. One of the packages you just install is a handy tool created by Chainlink Labs for encrypting your local environment variables. Please have a look at npx env-enc help to see all available commands.

• npx env-enc set-pw - to set your root password

• Next, we'll use env-enc set to set some envars:

  MUMBAI_RPC_URL - RPC_URL for Mumbai network (Infura, Alchemy, etc)

  PRIVATE_KEY - Private key for the account/address you used to sign up for Chainlink Functions

  ACCESS_TOKEN - Space and Time Access Token (only valid for 30 minutes)

  POLYGONSCAN_API_KEY - Used to verify contracts

  GITHUB_API_TOKEN - Personal access token, used by Chainlink Functions

• Visit https://github.com/settings/tokens?type=beta and

  • Click "Generate new token"
  • Name the token and enable read & write access for Gists from the "Account permissions" drop-down menu
  • Do not enable any additional permissions.
  • Click "Generate token" and copy the resulting personal access token

2. Space and Time Setup

Setup Data in Space and Time

📘

You can access SxT via REST APIs or JDBC Driver.

Here's a look at the gaming telemetry table SxT we're going to create:

Table: GAME_TELEMETRY_ARTHUR

1. First, CREATE your table:

CREATE TABLE TEST.GAME_TELEMETRY_ARTHUR (
    ID INTEGER,
    GamerId INTEGER,
    ActionType VARCHAR,
    AchievementId VARCHAR,
    collectableId VARCHAR,
    Level_ INTEGER,
    ItemId VARCHAR,
    Points INTEGER,
    PRIMARY KEY (ID)
) WITH "public_key=<your_biscuit_public_key>,
       access_type=public_write, 
       template=PARTITIONED, 
       atomicity=transactional"

📘

Please note, you will want to replace your_biscuit_public_key with public key used to generate the biscuit token you're sending along with this request. You'll also want to replace TEST with your schema name.

2. Load Table - This is where a game would be inserting its telemetry into SxT:

INSERT INTO TEST.GAME_TELEMETRY_ARTHUR (ID, GamerId, ActionType, AchievementId, collectableId, Level_, ItemId, Points)
VALUES 
    (1, 1, 'Game Started', '', '', 1, 'SwordNFt', 3),
    (2, 1, 'Attack', '', '', 1, 'SwordNFt', 3),
    (3, 1, 'Defense', '', '', 1, 'SwordNFt', 2),
    (4, 1, 'Kill', 'King', '', 1, 'SwordNFt', 100),
    (5, 1, 'Attack', '', '', 1, 'SwordNFt', 3);

3. View data that is loaded:

SELECT * from TEST.GAME_TELEMETRY_ARTHUR

SELECT 
    ItemId, 
    SUM(Points),
    CASE 
        WHEN SUM(Points) BETWEEN 100 AND 150 THEN 1
        WHEN SUM(Points) BETWEEN 151 AND 300 THEN 2
        WHEN SUM(Points) > 300 THEN 3 
        ELSE ''
    END AS SWORD  
FROM TEST.GAME_TELEMETRY_ARTHUR
GROUP BY ItemId;

Should return:

ITEMID  |SUM(POINTS)|SWORD|
--------+-----------+-----+
SwordNFt|111        |1    |

3. Connect SxT to Mumbai via Chainlink Functions

Now that we have our gaming telemetry table in SxT, we're going to connect everything up. The following steps were adapted from the Chainlink Functions repo and might be useful as a resource if you run into any issues getting Chainlink Functions setup.

The first thing we're going to do is simulate the full interaction. This is helpful because it allows us to identify potential issues before we deploy our dNFT contract.

1. Test/Simulate

   npx hardhat functions-simulate --gaslimit 300000

   ❗

   If the test fails, be sure your ACCESS_TOKEN is valid (not older than 30 minutes) in your encrypted envar file.

2. Deploy our contract to Mumbai:

   npx hardhat functions-deploy-client --network mumbai --verify true

3. Get the contract address from the previous step and set temporary envar:

   export CONTRACT_ADDRESS=<your_contract_address>

   Now is a good time to pull up your dNFT contract on OpenSea! Just place your contract address in here: https://testnets.opensea.io/assets/mumbai/<contract_address>/0

4. Create Functions Subscription and fund with LINK tokens:

   npx hardhat functions-sub-create --network mumbai --amount 2 --contract $CONTRACT_ADDRESS

   Get the subscription id and set a shell envar for:
   export SUB_ID=<CL_FUNCTIONS_SUB_ID>

5. Run request:

   npx hardhat functions-request --network mumbai --contract $CONTRACT_ADDRESS --subid $SUB_ID --gaslimit 300000

4. Level Up Your dNFT Sword

Now it's time to level up your swordNFT based on a gaming telemetry update to the data in SxT.

Add more game telemetry to SxT (sword 2)

INSERT INTO TEST.GAME_TELEMETRY_ARTHUR (ID, GamerId, ActionType, AchievementId, collectableId, Level_, ItemId, Points)
VALUES (6, 1, 'Collect', '', 'PotionA', 2, 'SwordNFt', 100);

SELECT 
    ItemId,
    SUM(Points),
    CASE 
        WHEN SUM(Points) BETWEEN 0 AND 150 THEN 1
        WHEN SUM(Points) BETWEEN 151 AND 300 THEN 2
        WHEN SUM(Points) > 300 THEN 3 
        ELSE ''
    END AS SWORD  
FROM TEST.GAME_TELEMETRY_ARTHUR
GROUP BY ItemId;

Push New Telemetry to Mumbai

1. Test/Simulate
   npx hardhat functions-simulate --gaslimit 300000

2. Run request:

   npx hardhat functions-request --network mumbai --contract $CONTRACT_ADDRESS --subid $SUB_ID --gaslimit 300000

   If the request fails, Double check your ACCESS_TOKEN. You need to refresh your ACCESS_TOKEN every 30 min.

   🚀

   Hit OpenSea and refresh the page to see your swordNFT change - https://testnets.opensea.io/assets/mumbai/<contract_address>/0

Add More Game Telemetry to SxT (sword 3)

As the game is played, more telemetry is loaded into Space and Time!

INSERT INTO TEST.GAME_TELEMETRY_ARTHUR(ID, GamerId, ActionType, AchievementId, collectableId, Level_, ItemId, Points)
VALUES 
    (7, 1, 'Collect', '', 'PotionB', 2, 'SwordNFt', 150),
    (8, 1, 'Attack', '', '', 3, 'SwordNFt', 9);

View the insert with:

SELECT * from TEST.GAME_TELEMETRY_ARTHUR

Or:

SELECT ItemId,
    SUM(Points),
    CASE 
        WHEN SUM(Points) BETWEEN 100 AND 150 THEN 1
        WHEN SUM(POINTS) BETWEEN 151 AND 300 THEN 2
        WHEN SUM(POINTS) > 300 THEN 3 
        ELSE 1 
    END AS SWORD  
FROM TEST.GAME_TELEMETRY_ARTHUR
GROUP BY ItemId;

Push New Telemetry to Mumbai

1. Test/Simulate
   npx hardhat functions-simulate --gaslimit 300000

2. Run the request:

   npx hardhat functions-request --network mumbai --contract $CONTRACT_ADDRESS --subid $SUB_ID --gaslimit 300000

Head back to OpenSea to see your level three swordNFT!