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Version: v3.x.x

Key Claiming

Prerequisites​

Overview​

Lit Actions have their own support for claiming. Instead of using an auth method use your own userId with the Lit Action's IPFS CID to create an appId. This allows for deriving custom claims without the need for an authentication method.

How it works

Instead of pre-authenticating the access token within an Authentication Method, claiming in a Lit Action allows you to define your own userId and use the Actions IPFS CID to form the key identifier through your own user identifier. This doesn't require a pre-authentication step which allows you to set up your own claims to then be routed on-chain with our contract-sdk.

Example​

Here is an example of how to claim a key using the Lit SDK and then mint a claim using the contract-sdk.

Calculating your key id​

You can create key id by taking the keccak256 hash of the theIPFSIdOfYourLitAction_yourUserId where theIPFSIdOfYourLitAction is the IPFS CID of your lit action that will be used for claiming and then yourUserId is the user id of the user.  You need to separate these items with an _ in the string.

const keyId = ethers.utils.keccak256(ethers.utils.toUtf8Bytes("theIPFSIdOfYourLitAction_yourUserId"))

Minting a claim​

  const res = await client.executeJs({
    sessionSigs,
    code: `(async () => {
      Lit.Actions.claimKey({keyId: userId});
    })();`,
    authMethods: [],
    jsParams: {
        userId: 'foo'
    },
  });

  let client = new LitContracts(signer: "<your pkp wallet or other signer>");
  let tx = await contractClient.pkpNftContract.write.claimAndMint(2, res.claims['foo'].derivedKeyId, res.claims['foo'].signatures);

Adding an auth method when minting a claim​

  const authMethod = {
    authMethodType: AuthMethodType.EthWallet,
    accessToken: JSON.stringify(authSig),
  };

  const authMethodId = LitAuthClient.getAuthMethodId(authMethod);

  const keyId = ethers.utils.keccak256(ethers.utils.toUtf8Bytes("theIPFSIdOfYourLitAction_yourUserId"))

  const res = await client.executeJs({
    sessionSigs,
    code: `(async () => {
      Lit.Actions.claimKey({keyId: userId});
    })();`,
    jsParams: {
        userId: 'foo'
    },
  });

  let client = new LitContracts(signer: "<your pkp wallet or other signer>");
  let tx = await client.pkpHelperContract.write.claimAndMintNextAndAddAuthMethods(
    res.claims['foo'],
   {
    keyType: 2,
    permittedIpfsCIDs: [],
    permittedIpfsCIDScopes: [],
    permittedAddresses: [],
    permittedAddressScopes: [],
    permittedAuthMethodTypes: [AuthMethodType.EthWallet],
    permittedAuthMethodIds: [`0x${authMethodId}`],
    permittedAuthMethodPubkeys: [`0x`],
    permittedAuthMethodScopes: [[BigNumber.from("1")]],
    addPkpEthAddressAsPermittedAddress: true,
    sendPkpToItself: true
   });
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