Conditions

This section focuses on Condition types and composition. There are three distinct, high-level categories of TACo access conditions:

• TimeCondition – time-based conditions using block height and other blockchain based timestamps. E.g. allow access for one week after the first request is made.

• RpcCondition – based on RPC calls as defined in Ethereum's Official API documentation. E.g. allow access if the address held ETH before 2020.

• ContractCondition – based on on-chain state, and can be any arbitrary contract function call. E.g. allow access if this requestor holds a special-purpose NFT.

Each access condition defines a returnValueTest used to compare the obtained value with the expected value for the condition.

Access conditions can also be combined via a CompoundCondition which provides the or, and & not logical operators.

Context variables provide the ability for placeholder values to be defined for conditions at encryption time, which will be dynamically populated at decryption time e.g. current user wallet address.

Multiple helper objects are provided to streamline the creation of conditions. An expressive API allows for granular control of conditions and examples of methods wherever possible.