🔮 Orb Contract •

Auction + Harberger taxed ownership. Used by orb.land. Uses Forge toolkit for building and testing. The contract combines the following areas of functionality:

• Auction. Allows the contract owner to start the Orb auction, determining the first Keeper of the Orb.
• Funds management. Allows any user to deposit and withdraw funds. Funds are used to make auction bids and pay Harberger Tax.
• Harberger Tax. Uses delayed accounting (settling) to allocate funds from the current Keeper to the contract beneficiary, based on the price set by the Keeper and tax rate.
• On-chain Orb Invocations. Allows the Keeper to periodically invoke the Orb, requesting a response from the Orb creator.
• ERC-721 compatibility. All transfers revert, but otherwise, the contract appears as supporting all ERC-721 functions.

The contract is fully documented in NatSpec format.

Usage

forge install foundry-rs/forge-std openzeppelin/openzeppelin-contracts # dependencies
forge test # tests
make anvil # local node
make deploy-anvil # deploy to local node in another terminal

License

Released under the MIT License.

Credits

• Eric Wall - Concept and mechanics design
• Jonas Lekevicius - Contract implementation
• Odysseas.eth - Tests, toolkit setup and many other contributions
• OpenZeppelin Contracts - Contract is based on OZ ERC-721 and Ownable implementations