For an agreement in a Blockchain network that can be carried out in terms of legal, it must meet a number of traditional legal standards.

There must be a clear and acceptable proposal, in which the terms of a smart contract are encrypted and deployed on the blockchain and the interaction of a part of the contract means accepting. The review, or something of the exchange value between the parties is also required, often related to digital or cryptocurrencies. 

The parties must intend to create a legal binding agreement, which may be difficult to determine due to the automatic nature of smart contracts. All parties must be legal to end the agreement and the goal of the contract must be legal. Compliance with current legal standards and regulations, such as the Law on Data Protection and Financial Transactions, is very important. 

The security and immutability of Blockchain technology provides a solid basis for the agreement to be executed, ensuring that once a smart contract, it cannot change without consensus.

However, this immutability also means that any error in the contract code can be difficult to overcome, emphasizing the importance of tests and audits in tests. 

By responding to these criteria, the Blockchain network agreements can perform legal implementation, providing a powerful frame for digital transactions.