Kwil ERC721 Oracle Example

This is an example of how to use the Kwil ERC721 Oracle to token gate access based on the ownership of an ERC721 token.

How it Works

The oracle will listen for the Transfer event on the ERC721 contract and will update the access control list based on the ownership of the token.

The access control list is a schema in cmd/genesis.kf. It will be deployed at the network genesis.

A sample schema for checking addresses against ERC721 ownership can be found in ./sample_schema.kf.

How to Run

1. In cmd/erc721_oracle.go, update the contractAddress and contractStartHeight to the address of the ERC721 contract you want to listen to and the Ethereum block height at which the contract was deployed.

var (
    contractAddres = "your_contract_address"
    contractStartHeight = 12345678
)

2. Build the binary with the oracle.

go build -o .build/kwild-erc721 ./cmd

This will create a binary called kwil-erc721 in the .build directory.

3. Set up the node config files.

.build/kwild-erc721 admin setup init -o .build/node_config

This will create a directory called node_config in the .build directory.

4. Add an Ethereum RPC in .build/node_config/config.toml.

The config must be added to the [app.extensions] section. Use a websocket address.

[app.extensions]

[app.extensions.erc721_oracle]

rpc_url = "wss://mainnet.infura.io/ws/v3/your_api_key"

5. Start docker following the standard node start instructions.

6. Start the node.

.build/kwild-erc721 node -r .build/node_config

Once started, the oracle will sync with the Ethereum network and listen for the Transfer event on the ERC721 contract. It will update the access control list based on the ownership of the token.

How to Test

After the node is running and the oracle is caught up with the Ethereum network, you can do the following to test:

1. Deploy the schema in ./sample_schema.kf.

You can deploy the schema using the Kwil CLI.

2. Verify Write Token Gating: Call the add_message procedure. If the address is not the owner of the ERC721 token, the procedure will fail.

You can call the procedure using the Kwil CLI.

3. Verify Read Token Gating: Call the get_messages procedure. If the address is not the owner of the ERC721 token, the procedure will fail.

You can call the procedure using the Kwil CLI.