Bs721 Basic

This is a basic implementation of a bs721 NFT contract. It implements the BS721 spec and is designed to be deployed as is, or imported into other contracts to easily build bs721-compatible NFTs with custom logic.

Implements:

• BS721 Base

Implementation

The ExecuteMsg and QueryMsg implementations follow the BS721 spec and are described there. Beyond that, we make a few additions:

• InstantiateMsg takes name, symbol (for metadata) and uri, as well as a Minter address. This is a special address that has full power to mint new NFTs (but not modify existing ones)
• ExecuteMsg::Mint{token_id, owner, token_uri} - creates a new token with given owner and (optional) metadata. It can only be called by the Minter set in instantiate.
• QueryMsg::Minter{} - returns the minter address for this contract.

It requires all tokens to have defined metadata in the standard format (with no extensions). For generic NFTs this may often be enough.

The Minter can either be an external actor (e.g. web server, using PubKey) or another contract. If you just want to customize the minting behavior but not other functionality, you could extend this contract (importing code and wiring it together) or just create a custom contract as the owner and use that contract to Mint.

If provided, it is expected that the token_uri points to a JSON file following the ERC721 Metadata JSON Schema.

Running this contract

You will need Rust 1.44.1+ with wasm32-unknown-unknown target installed.

You can run unit tests on this via:

cargo test

Once you are happy with the content, you can compile it to wasm via:

RUSTFLAGS='-C link-arg=-s' cargo wasm
cp ../../target/wasm32-unknown-unknown/release/cw721_base.wasm .
ls -l cw721_base.wasm
sha256sum cw721_base.wasm

Compiling

To compile all the contracts, run the following in the repo root:

docker run --rm -v "$(pwd)":/code \
  --mount type=volume,source="$(basename "$(pwd)")_cache",target=/code/target \
  --mount type=volume,source=registry_cache,target=/usr/local/cargo/registry \
  cosmwasm/workspace-optimizer:0.12.9

This will compile all packages in the contracts directory and output the stripped and optimized wasm code under the artifacts directory as output, along with a checksums.txt file.

If you hit any issues there and want to debug, you can try to run the following in each contract dir: RUSTFLAGS="-C link-arg=-s" cargo build --release --target=wasm32-unknown-unknown --locked

Importing this contract

You can also import much of the logic of this contract to build another BS721-compliant contract, such as tradable names, crypto kitties, or tokenized real estate.

Basically, you just need to write your handle function and import bs721_base::contract::handle_transfer, etc and dispatch to them. This allows you to use custom ExecuteMsg and QueryMsg with your additional calls, but then use the underlying implementation for the standard bs721 messages you want to support. The same with QueryMsg. You will most likely want to write a custom, domain-specific instantiate.