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Caveat Enforcers

The original delegator delegates with authority=0x00. A delegation with authority=0x00, and no caveats, gives the delegate the same exact powers as the delegator. This means that if the contract is Ownable, the delegator just allowed the delegate to transferOwnership.

In order for the original delegator to limit the delegate's powers, he needs to introduce caveats. Caveats are a set of contracts that act as constraints to the delegate's powers. If the delegator had set an AllowedMethodsEnforcer for a specific function (e.g. the function setPurpose(string _newPurpose), then any attempt of the delegate to transferOwnership will fail.

What's even better? Caveat Enforcers add run-time conditionals to EVM transactions.

Native EVM transaction can NOT enforce when/how the transaction is executed.

When signing a Transaction an Account is NOT able to enforce important run-time rules and conditions:

Basic Run-Time Rules missing from native EVM transactions:

  • When (block.timestamp) the transaction can be executed i.e. before/after/between timestamp(s).
  • What block (block.blockNumber) the transaction must be included in i.e. before/after/between blockNumber(s).

Advanced Run-Time Rules missing from native EVM transactions:

  • PROBLEM: If the transaction requires other on-chain state conditionals (oracles) to be true/false before executing.
  • SOLUTION: The Delegatable framework's Caveat Enforcers enable nuanced run-time transaction execution rules that unlock these transaction signing super powers!

Examples of (primitive) Enforcers


Enforcers can be composed together. A single enforcer perhaps even multiple times in certain situations.

For example a User may choose to use the TimestampEnforcerBefore and the ERC20AllowanceEnforcer enforcers to give a friend permission to spend up to 100 tokens for the next 30 days.

As long as the verifying contract inherits from Delegatable.sol, developeds can focus on what they do best, and write their own, custom made enforcers for their Dapps', and users' needs.