README.md

Delegatable Diamond

DelegatableFacet.sol is a standalone contract for adding The Delegatable Framework to ERC-2535 Diamond contracts. Diamonds are a type of proxy contract that allows people to add new "facets" to it (like adding a method to a mutable object).

Once this facet is added to a Diamond, it will have all of the Delegatable interfaces exposed.

Setup and Requirements

Any authority checks in the other facets must not use msg.sender directly, but should use our special _msgSender() override method, per the normal Delegatable integration process. You can see an example of this substitution in our modified LibDiamond file.

If you're on the Ethereum mainnet, you can use our pre-deployed Delegatable Diamond Singleton at 0x22B7922dEA4816799380B78944d45669a37f4e98.

If you're using ERC-712 signTypedData signatures, it's probably a best practice to re-use your domainHash between other signatures and the Delegatable ones. To reuse the domainHash storage with this facet, you can copy the AppStorage usage in DelegatableFacet.sol.

If you're already using that exact pattern for your domainHash, you can simply add the facet with no init code. If you are not using that exact pattern for storing a domainHash, you must add your facet with an initCode for setting that value:

// Generate delegatable init code to generate domain typehash
const populatedTx =
  await DelegatableFacet.populateTransaction.setDomainHash(CONTRACT_NAME);
const initTypehashBytes = populatedTx.data;
// Add delegatable facet to the diamond
await Diamond.diamondCut(
  [
    {
      facetAddress: '0x22B7922dEA4816799380B78944d45669a37f4e98',
      action: FacetCutAction.Add,
      functionSelectors: getSelectors(DelegatableFacet),
    },
  ],
  // run delegatable init code to generate domain typehash
  '0x22B7922dEA4816799380B78944d45669a37f4e98',
  initTypehashBytes
);

Once you've done that setup, you'll be ready to get started issuing delegations and letting people use them to call methods on your behalf!

Some further reading to get set up:

• A high level summary of the goals of the Delegatable framework.
• A series of conversations about the framework on YouTube.
• A reference app called MobyMask.
• A JS library for creating & redeeming delegations.