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Non-Fungible Token On-chain storage (TIP-4.4)

Requires: TIP-4.1 Requires: TIP-6.1

Abstract​

Using the Storage contract, you can store NFT-related bytes in blockchain

Motivation​

Fault tolerance. If off-chain services are unavailable, the user will view NFT-related bytes, because it is stored on-chain.

Specification​

The keywords “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”, “RECOMMENDED”, “MAY”, and “OPTIONAL” in this document are to be interpreted as described in RFC 2119

Contracts​

  • Collection - TIP4.1 contract that minted token and store Storage contract code
  • NFT - TIP4.1 contract that store token information and Storage contract address
  • Storage - contract that store token byte content. Storage is independent. Storage doesn’t store NFT address because NFT contract address can be changed by burning and redeployment from another collection.

Collection​

Every TIP-4.1 Collection contract must implement TIP4_4Collection

pragma ton-solidity >= 0.58.0;

interface TIP4_4Collection {
    function storageCode() external view responsible returns (TvmCell code);
    function storageCodeHash() external view responsible returns (uint256 codeHash);
    function resolveStorage(address nft) external view responsible returns (address addr);
}

NOTE The TIP-6.1 identifier for this interface is 0x6302A6F8

TIP4_4Collection.storageCode()​

function storageCode() external view responsible returns (TvmCell code);
  • code (TvmCell) - storage contract code

TIP4_4Collection.storageCode()​

function storageCodeHash() external view responsible returns (uint256 hash);
  • hash (uint256) - storage contract code hash

TIP4_4Collection.resolveStorage()​

function resolveStorage(address nft) external view responsible returns (address addr);
  • nft (address) - token contract address
  • addr (address) - storage contract address

NFT​

Every TIP-4.1 NFT contract must implement TIP4_4NFT

pragma ton-solidity >= 0.58.0;

interface TIP4_4NFT {
    function onStorageFillComplete(address gasReceiver) external;
    function getStorage() external view responsible returns (address addr);
}

NOTE The TIP-6.1 identifier for this interface is 0x009DC09A

TIP4_4NFT.onStorageFillComplete()​

function onStorageFillComplete(address gasReceiver) external;
  • gasReceiver (address) - address of contract that receive all remaining contract balance then last chunk filled Calling the Storage.fill() on storage contract that fills the last chunk should call TIP4_4NFT.onStorageFillComplete() on token contract

TIP4_4NFT.getStorage()​

function getStorage() external view responsible returns (address addr);
  • addr (address) - storage contract address

Storage​

Every Storage contract must implement TIP4_4Storage

pragma ton-solidity >= 0.58.0;

interface TIP4_4Storage {
    function fill(uint32 id, bytes chunk, address gasReceiver) external;
    function getInfo() external view responsible returns (
        address nft,
        address collection,
        string mimeType,
        mapping(uint32 => bytes) content,
        string contentEncoding
    );
}

NOTE The TIP-6.1 identifier for this interface is 0x204D6296

TIP4_4Storage.fill()​

function fill(uint32 id, bytes chunk, address gasReceiver) external;
  • id (uint32) - chunk number. From 0 to 4 294 967 295
  • bytes (chunk) - data. Max size of data is limited by external message payload size. Maximum size external message payload size is 16KB at 2022-03-18.
  • gasReceiver (address) - address of contract that receive all remaining contract balance then last chunk filled.

TIP4_4Storage.getInfo()​

function getInfo() external view responsible returns (
    address nft,
    address collection,
    string mimeType,
    mapping(uint32 => bytes) chunks,
    string contentEncoding
);
  • nft (address) - token contract address
  • collection (address) - collection token contract address
  • mimeType (string) - MIME types are defined and standardized in IETF's RFC 6838
  • content (mapping(uint32 => bytes)) - byte content. Maximum content size is 4 294 967 295 chunks * chunk size. Max size of data is limited by external message payload size. Maximum size external message payload size is 16KB at 2022-03-18 Maximum content size is 4 294 967 295 * 16KB ≈ 69TB at 2022-03-18.
  • contentEncoding (string) - Was it compressed by any algorithm. If it was compressed with zstd contentEncoding need to be zstd, all other need to be like http content encoding

Visualization​

Legend​

Legend Legend

NFT minting with Storage​

Storage

Storage filling​

Storage

Storage with Index​

How to interaction on-chain indexes and Storage contracts Storage